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Team Name: Gekko

1. En H j z d V V Figure C15 Gekko bulkhead manufacturing drawing RX14 GEKKO SEDv5 0 9aug13 A DLR and SSC cooperation Ez Sea d m Ba seg Fe ais D Ut Homng Or A Bez i CEGE experiment rmadule GEKKD experiment module CZleg E 1 Page 172 EUROLAUNCH A DLR and SSC cooperation aaj s B LE ZA Kid gd i Ai SS d k E 2571 7 Sa A tans alana EE Ze EME MHT Ur708 pe AT Figure C17 Test setup of the PSU RX14 GEKKO SEDv5 0 9aug13 Page 173 EUROLAUNC A DLR and SSC cooperation Figure C18 OBDH PCB flight model RX14 GEKKO SEDv5 0 9aug13 Page 174 Data sheets of the coaxial triaxial cable assemblies d Telegartner 1 4 KARL GARTNER GMBH order number J01151A0331 SMA Receptacle female for Printed Circuits in Press In Technology 1 4 36 UNS Technical Attributes Remarks 00 Further technical information on request Product description 2013 Teleg rtner Karl Gartner GmbH Technische Anderungen vorbehalten Technical changes reserved www telegaertner com Lerchenstr 35 D 71144 Steinenbronn Tel 49 0 7157 125 100 Fax 49 0 7157 125 120 E Mail info telegaertner com RX14 GEKKO SEDv5 0 9aug13 Page 175 EUROLAUNCH A DLR and SSC cooperation r Telegartner 1 4 KARL GARTNER GMBH order number J01150A0061 SMA Angle Plug Crimp G7 RG 316 U Technical Attributes ERC Product description The SMA series is
2. 120V for the positive ions and 10mV to 120V every second for both positive and negative The bias voltage of the Gerdien condensers pA shall be adjusted in the range of 10mYV to for negative ions 2 PA The bias voltage of the Gerdien condensers shall be adjusted in the range of 10mV to RX14 GEKKO SEDv5 0 9aug13 Page 69 EuROLAUNCH and SSC coo 50V for the positive ions and 10mV to 50V for negative ions The bias voltage adjustment of the Gerdien R T P 5 condensers shall be performed with a minimum accuracy of 10mV be measured in the range of 5pA to 2 nA The current measurements of the Gerdien A R T P 7 condensers shall be performed with a maximum accuracy of 1pA The PSU shall provide a 5V 2 5V and a 3 3V output with 10 accuracy eave NN a 120V output with 10 accuracy PD ae MN a 60V output with 10 accuracy RE I possible in the range of 20mA to 200mA P 9 10 P The input current measurement shall be R T P 11 performed with an accuracy of 2mA resolution aic NN NN A possible in the range of 20V to 40V The input voltage measurement shall be HI P 13 performed with an accuracy of 200mV resolution The experiment shall be designed to withstand A T 1 the mechanical loads during the complete flight of the REXUS rocket The experiment shall be designed to operate in A T the temperature profile of the pre flight and flight phase
3. Page 17 EuROLAUNCH Mechatronics Engineering PhD student Mechanical design 15 Electrical Engineering MSc student Electronic and software design Outreach David Szabo is graduated in May 2012 Electrical Engineering MSc student Digital electronics and software design Backup team member follows the Gekko team activity can be involved in the work if needed Electrical Engineering PhD student Project management Electronic design Outreach 15 RX14 GEKKO SEDv5 0 9aug13 Page 18 EuROLAUNCH 2 EXPERIMENT REQUIREMENTS 2 1 Functional Requirements condensers The experiment shall adjust the bias voltage of the F 2 Gerdien condensers according to the velocity of the The experiment shall measure the ion mobility F 1 during the flight of the rocket using two Gerdien rocket The experiment shall measure the current of the Gerdien condensers The experiment shall measure the input current and input voltage of the PSU F4 The experiment shall use its own PSU to ensure continuous power supply for the electronics The experiment shall store all measured data into an on board non volatile memory The experiment shall send the data to the ground F 7 station through the RXSM during the whole flight of the rocket RX14 GEKKO SEDv5 0 9aug13 Page 19 EuROLAUNCH 2 2 Performance reguirements The ion mobility measurements shall be performed 2 The ion mobility measurements shal
4. the OBDH PCB and the PSU PCB were inspected in the next step We haven t found any irregularity at the first time Figure 54 55 RX14 GEKKO SEDv5 0 9aug13 Page 130 EUROLAUNCH A DLR and SSC cooperation Figure 54 OBDH board Figure 55 PSU board After the first inspection we haven t found the reason of the short circuit The electronics box was reassembled connected to the GSE and powered with a current limited benchtop power supply Ihe power consumption was below the nominal 25mA input current and the communication couldn t be established After the next disassembly we have found a burning point on the inner wall of the electronics box under the PSU board Figure 56 This point was under a resistor pin one of the few pins that the 28V is directly connected to Figure o shows the schematic of the UVLO circuit with the highlight of the corresponding pin Figure 56 a The PSU PCB bent down and touched the box Figure 56 b Burning on the box RX14 GEKKO SEDv5 0 9aug13 Page 131 EuROLAUNCH V e at fe i Figure 57 The UVLO circuit The pin of R20 touched the structure The PSU was further investigated to find the cause of the failure We realized that the voltage reference IC LM285 1 2 was damaged and the reference voltage was much lower than in normal case Due to the failure of the reference voltage the control circuit blocked the operation of the PSU By this point the La
5. BIFEI National Semiconductor Corp Difet Burr Brown Corp APPLICATIONS e PRECISION PHOTODIODE PREAMP e MEDICAL EQUIPMENT e OPTOELECTRONICS e DATA ACQUISITION e TEST EQUIPMENT Trim 10k 1 Trim 10KC c 5 OPA124 Simplified Circuit NOTES 1 Omitted on SOIC 2 Patented Intemational Airport Industrial Park Mailing Address PO Box 11400 Tucson AZ 83724 Street Address 6730 S Tucson Blvd Tucson AZ B3706 Tel S20 745 1111 Twx 310 332 1111 Intemet hip www burr brown com FAXLine 800 542 5133 US Canada Only Cable BER RX14 GEKKO SEDv5 0 9aug13 RP Telex 065 5431 FAR 320 883 1510 Immediate Product Info BO 5455 6132 Page 180 EUROLAUNCH A DLR and SSC cooperation SPECIFICATIONS ELECTRICAL At Voc 15VDC and T 25 C unless otherwise noted OPA124U P OPATZ4UAPA INPUT NOISE Voltage fg 10Hz fo 100Hz fo 1kHz fo 10kHz fa 10Hz to 10kHz fa 0 1Hz to 10Hz Current f 0 1Hz to 10Hz fo 0 1Hz thru 20kHz OFFSET VOLTAGE Input Offset Voltage Vem OVDC vs Temperature Ta Ty tO Tmax Supply Rejection Ka 10V to 18V vs Temperature Twin to Tmax H I H S IMPEDANCE Differential Common Mode VOLTAGE RANGE Common Mode Input Range Common Mode Rejection vs Temperature FREQUENCY RESPONSE Unity Gain Small Signal Full Power Response 20Vp p R 2kQ Slew Rate Vo 10V R 2kQ THD Settling Time 0 1
6. G5 RG 223 U RG 141A U RG 142B U MIL clamp IP 67 7 16 28 UNEF 916 2 Technical Attributes G1 RG 58C U G5 RG 223 U RG 141A U RG 142B U 1 0 2 95 AF Product description The TNC series is a commonly used coax connector The same size as BNC connectors but with a threaded coupling mechanism this connector can be used up to 11 GHz Both 50 Q and 75 Q impedances are available Connector styles are available for flexible conformable and semi rigid cable types Versions of the TNC connector are available for mounting to printed circuit boards using both through hole soldered and through hole press fit techniques Both crimp and clamp cable termination processes are used for this series Applications for these connectors range from signal and data to video transmission where vibration resistance is required TNC s are a low cost high frequency solution for coax connections Mating face sealing for TNC connectors between plug and jack mated according to IP 68 The classifications are general statements for the relevant series Individual connectors may deviate from the values shown If in doubt please consult our engineers Note Combination connectors and cable clamps can be utilised to create a further number of TNC connector variations 2013 Teleg rtner Karl Gartner GmbH Technische nderungen vorbehalten Technical changes reserved www telegaertner com Lerchenstr 35 D 71144 Steinenbronn Tel 49 0 7157 125
7. ithe range of 20V to 40V 10 RX14 GEKKO SEDv5 0 9aug13 Page 20 EuROLAUNCH P13 The input voltage measurement shall be performed with an accuracy of 200mV resolution 2 3 Design Requirements The experiment shall be designed to withstand the D 1 mechanical loads during the complete flight of the REXUS rocket The experiment shall be designed to operate in the D 2 temperature profile of the pre flight and flight phase of the REXUS The experiment thermal dissipation must not heat D 3 up the outer structure more than 10 C over the ambient temperature through cable more than 70 C D The experiment thermal dissipation must not heat up parts facing other modules more than 50 C The heat transport by convection must be limited in such a way that the air temperature at the module A 9 interfaces does not exceed the ambient temperature by more than 10 C The experiment thermal dissipation must not heat D 4 up the parts close to or in contact with the feed 1mbar air pressure TBC The experiment shall be designed to operate under The experiment shall be connected to the RXSM experiment interface The experiment interface connector shall be a D SUB 15 male type 10 The experiment shall be able to communicate on the RS422 telemetry interface The telemetry data rate shall be less than 30kbps 12 The experiment shall be powered over the RXSM A power interface RX14 GEKKO SEDv
8. Gain 1 R 2kQ 0 01 10V Step Overload Recovery 50 Overdrive Gain 1 RATED OUTPUT Voltage Output Current Output Output Resistance Load Capacitance Stability Short Circuit Current POWER SUPPLY Rated Voltage Voltage Range Derated Current Quiescent lo 0mADC TEMPERATURE RANGE Specification Twin and Tmax Storage 8 Junction Ambient PDIP SOIC Specification same as OPA124U P NOTES 1 Offset voltage offset current and bias current are measured with the units fully warmed up For performance at other temperatures see Typical Performance Curves 2 Overload recovery is defined as the time required for the output to retum from saturation to linear operation following the removal of a 5096 input overdrive 3 For performance at other temperatures see Typical Performance Curves 4 Sample tested 98 confidence 5 Guaranteed by design BURR BROWN OPA124 L2 RX14 GEKKO SEDv5 0 9aug13 CONNECTION DIAGRAMS Top View PACKAGE ORDERING INFORMATION PACKAGE PRODUCT OPA124U OPA124P OPA124UA OPA124PA OPA124PB PACKAGE 8 Lead SOIC 8 Pin Plastic DIP 8 Lead SOIC 8 Pin Plastic DIP 8 Pin Plastic DIP DRAWING NUMBER Page 181 EUROLAUNCH A DLR and SSC cooperation BIAS OFFSET CURRENT DRIFT pA max NIC max TEMPERATURE RANGE 25 C to 85 C 25 C to 85 C 25 C to 85 C 25 C to 85 C 25 C to 85 C NOTE 1 For detailed drawing and dimensi
9. The specific length used in eguation 4 is for example the profile length of an airplane wing therefore it is recommended to use the full length of the condenser or the height of the module From the foregoing X 0 3 m Re 2 8355 10 If the value of the Reynolds number is such high well above the value of Re 2320 then the resulting flow is certainly turbulent This supports the initial hypothesis that it is recommended to assume turbulent flow in the boundary layer Dynamic viscosity The dynamic viscosity of the air is 10 Pa s magnitude and it increases with the rising of the temperature During the calculations using the dynamical viscosity of the air at the temperature of 0 C is appropriate its value is Uu 1 71x 10 Pa s Kinematic viscosity The kinematic viscosity can be converted from the dynamic viscosity by the following formula v u 0e 5 The density of air at the temperature of 0 C 1 293 kg m Thus the dynamical viscosity of air is v 1 71 10 1 293 1 3225 10 m s The thickness of the boundary layer from the data obtained formerly RX14 GEKKO SEDv5 0 9aug13 Page 96 EUuROLAUNCH x 1 4 1 7 m distance from the tip of the rocket dmin 0 01728 m 17 28 mm dmax 0 020989 m 20 989 mm Considering the safety factor the final result is dmax N 0 020989 2 0 041978 m 42 mm In conclusion it can be said if the condenser is placed from 40 50
10. as a secondary effect the voltage reference circuit was damaged ZA Results 7 3 1 Technical and scientific results The short circuit on the power line occurred after lift off ant therefore the Gekko experiment was unable to perform measurements The scientific objectives Obj 1 3 were not met The technical objectives objective 4 and 5 are fulfilled We successfully developed an experiment to conduct Gerdien condenser measurements and even if the first flight was not successful we gained a lot of experience 7 3 2 Outlook improvements and recommendations At this time we are working on the improvement of the experiment in order to come up a proper solution to prevent the failures that we experienced during the REXUS14 launch Three different parts are targets of improvement the RX14 GEKKO SEDv5 0 9aug13 Page 135 EUuROLAUNCH insulation ring on the tip of the sensors the attachment of the triaxial cables and the condensers and the electronics box construction and placement The insulation ring was made from a special thermo plastic material Appendix C of which the maximum short term a few hours operating temperature is 500 C The deformation of this ring was not a critical failure but still a problem that shall be corrected A possible solution for this problem is to use a commercial ceramic ring In that case the mechanical parameters shall be adjusted to the available dimension of the ceramic ring The most
11. c Seo ree amp 062 eis matos amd fer mda that d nof show a nming 6067 omiaa Bora o dac ea i al maturation n dr of 23 Ci 808 FH T5 apom 2 bw howa ip applicators whem sesso e BO baai b apnd cue CEN mhi pared of tima there ba acapar n finale sang 0 1137 13 ried a 23 C of deut ae n 8 compared with fa ISO 1387 33 a org at siut The tamporacure valid Gren ham ja thun based on the tharma ox dative dag alaton dich tak az pion and caia reeled or Confident ch limear thermal exp kr Im proper Mite how tfi hd rn as imum aint rules E Linn ca p snc d temper atum dagende Ip cgo amnia cn the duration SE aid dea and tha m di at Mtaa n imama fo which ha Wale Als abobween Z1 an matar ia ah jactad Ti impact arangi jarma wh ncrecmnm empa dura Hw minimum arwabis Gavia onporantg m proanicsdy maniy determined by tha geet bo which tha material In subjected ta im zant Tha valtia gon here dm haod on unfwoiralie impar Max aia aeria Tam perat ar ke cardticnm and may consequentis not ba canaidnmed an being he Head Mr gt abad practica limit A r Hy D hee and mated ratings darivad from raw material applar data anti Ghar publcaiona ara nal pindal fo rolad hazarda pramenbed by tha material under aval fira conitiona Thea ie es ma UL Ale Hunter weba Nr Corto CURD PEE siok Bog 3 i r a hapaa W Munt of the figures gian for tha machanksd properas ara i r aver valune of tagia run on ity et ipacmanm machinad out Mechani
12. no responsibility for the use of this information and all use of such information shall be entirely at the user s own risk Prices and specifications are subject to change without notice No patent rights or licenses to any of the circuits described herein are implied or granted to any third party BURR BROWN does not authorize or warrant any BURR BROWN product for use in life support devices and or systems RX14 GEKKO SEDv5 0 9aug13 BURR BROWN OPA124 Page 182 EUROLAUNCH A DLR and SSC cooperation zz PODUHEMZIMIDAZDI E PHI Duratron CU60 PBI b Duratron CUSO PBI offers the highest temperature resistance and best mechanical property retention over 200 T of I all unfilled themoplastics Duratron CUSO PBI is very clean in terms of ionic impurity and does not outgas except LH water These characteristics make this material extremely attractive to high4tech industries such as semiconductor LLI Ze and aerospace industries Usually Duratron CUGO PBI is used in critical components to decrease maintenance E costs and to gain valuable production uptime It i amp used to replace metals and ceramics in pump components et valve seats high tech valves bearings rollers high temperature insulators WERE cd Physical properties indicative values e mae nad i Aonnfim he mathid 1 of H7 ad dm onde S0 mm x 1 o m The figures given br Hue properties ane for W most part ELLE Vies EC Ra REM Mt EE
13. reg line 0 20pA e AMP 10G bias V AMP 1G bias 0V T 19 C 126 Amplifier output mV gt E 128 130 132 134 Current pA Figure 58 precision amplifier thermal test Note that the flight model PCB was modified after the thermal test so these figures can be used to calculate the voltage drift but the absolute values are not correct The temperature decreased by 45 C during the thermal test and the offset of the precision amplifiers changed _ 2 error in measured input offset voltage positive amplifier PBB WV PBB WV negative amplifier 14 7 mV Ss 92 uV The measured input offset voltage drift is in the limit 1 22uV C and 2 04uV C The temperature is monitored in the Gekko experiment so the temperature effect can be considered in the data evaluation The bias voltage amplifiers were tested on room temperature and on 20 C The results are shown on the next figure RX14 GEKKO SEDv5 0 9aug13 Page 108 EUROLAUNCH A DLR and SSC cooperation Bias voltage 30xBias 30xBiast T 20 C Bias voltage V 0 500 1 000 1 500 2 000 DAC output V 30xBias Bias 30x T 20 C ell DI si o gt un Ie ea DAC output V Figure 60 Bias voltage amplifier negative he test shows that the temperature has no notable effects on the bias voltage amplifiers At 30x mode the bias DAC rate in case of the positive amplifier is 31 4 and 31 6 for the
14. 28 each condenser 0 125 x 0 165 x 0 105 electronic box RX14 GEKKO SEDv5 0 9aug13 Page 42 EuROLAUNCH Experiment footprint area in m 0 0189 electronics box Experiment volume in m 4 55 x 10 each condenser 2 x 10 electronic box Experiment expected COG centre of Experiment COG can be adjusted to gravity position coincide with the geometrical centre of the rocket RX14 GEKKO SEDv5 0 9aug13 Page 43 EUROLAUNCH 4 4 Mechanical Design The mechanical design of the experiment can be separated to two main parts the condensers and the electronics box In the following each unit will be described in detail Figure 17 Placement of the condensers The Gerdien condensers The configuration of the condenser is shown in figure 18 The inner electrode is end in sleeve nuts on both ends The spacers of the centre electrode are fixed into these sleeve nuts The excursion is prevented by screw bond and fixation by shape The spacers of the inner electrode are fitted in the notches of the outer electrode The spacers of the inner electrode and the inlets are made of non conductive material that can withstand the high temperature practically ceramics using plastics is preferable because of the easier manufacturing we plan to use a plastic material that can be used for up to 5007C the inner electrode will be made of bronze all other parts are stainless steel RX14 GEKKO SEDv5 0 9aug13 Page 44
15. 7000 8000 Condenser current pA Figure 54 Characteristic of the precision amplifier 0 6nA RX14 GEKKO SEDv5 0 9aug13 Page 105 EUROLAUNCH A DLR and SSC cooperation ra ca a AMP 10G Itage mV ra cC un Reg line Out put vo AMP 100M REG line 0 6n gt E E m z eg L rm ei Condenser current pA Figure 56 Characteristic of the precision amplifier 0 6nA After the tests we fitted a regression line to the points of the characteristics The estimation of the measured current of the condensers is based on these RX14 GEKKO SEDv5 0 9aug13 Page 106 ELULROLAUNCH lines The parameters of the regression in the full range 0 6nA and 0 6 nA on room temperature are the following NN slope mV pA offset mV T 20 C postive a meme am Test 3 oince the input offset voltage of the precision amplifiers are depending on the temperature tipical 2uV C max 4uV C see datasheet in Appendix C the voltage drift shall be measured The results presented on figure 57 and 58 Amplifier 0 20pA 24 22 20 gt E 3 18 reg line 0 20pA t 16 AMP 10G Bias 0V E e AMP 1G Bias 0V T 19 C e 14 12 10 0 5 10 15 20 25 Lonerator pA Figure 57 precision amplifier thermal test RX14 GEKKO SEDv5 0 9aug13 Page 107 EuROLAUNCH AMP 10G bias OV 0 20 pA 114 418 118 120 122
16. Balassa Adrain Gugyin Andras Futo Supporting professors Jozsef Szabo Antal Banfalvi Laszlo Csurgai Horvath Gabor Kocsis Visiting guest from BioDos Vilmos Gorocz Veronika Grosz Borbala Marosvari Daemon PICTURES RX14 GEKKO SEDv5 0 9aug13 Page 156 EUROLAUNCH REXUS Experiment Acceptance Review EUuROLAUNCH Page 2 GENERAL COMMENTS e Experiment not ready Condensers will be mounted within the next two weeks e Venting hole will be manufactured as well as new covers by the team e Team has to move in another building but work will not be affected to much e Notest with service System Simulator possible boards not ready no optocoupler available e Teamis still big many people to work on it PANEL COMMENTS AND RECOMMENDATIONS Science e Science achievements will be fulfilled Requirements and constraints SED chapter 2 e No comments Mechanics SED chapter 4 2 1 amp 4 4 e Team will make a second venting hole on the opposite of the old one as recommended in the user manual e Team will manufacture new cover plates which fit to the bore holes e Gerdien Condensers are under manufacturing will be ready after SEW e Greater holes will be manufactured into the bulkhead for assembly of the experiment e Teamimplemented all requests from CDR Electronics and data management SED chapter 4 2 2 4 2 3 4 5 amp 4 7 e 2PCB are ready mother board OBDH e 2PCBunder population production PSU 4
17. Di Lao 999 ONE Il STIX SVX E AO0ZCL SOWL AO0Sc UL VO LX AS 80WL ja AGT ZOWL AOZcL SOWL SPD 0 1X MOZIT SONL E AS VONL l EA SOT ZO 1X snan eoWL Snel LOWL N2 G UN ZK LN QN5V Oo Lt I8 1X Datz H9608V4 H9608VJ H9608VJ D Ee aa AO0ZL SONL CI AS V Ka Wi WI Wt T O 5 0cH LH eeu Ji o rav ozs 4095 Heu OG all pes eiat t98 wes LC gol HAD gy Olu O icm YZZZZNZ P 9 u0Zt 9 uO t AM e KS 4081 T gt 699 199 Heel nokni E pl uoo o AQ U0LP rav pes OW 890 WER esu 4001 eS aZol m xosi Vor lent CN z1 9H d N 9 U0ZY 9 UOZv E FU o 099 859 XNBA 5 091 O UO t mim rt GJ Hery EN ES VOL xm 9 S ONS ONS Dk PON d _ ER LLO lvy JolA A LL Im ad L DEN rav an9a 9085N I OSU 8ta uot EES H T gs E Ed PA Q e FS 971 4 BfF 0 xneA snan zoNL R oro dai dozz 8 7 AQSZ UDLP BOSZ UOLP 69 s ANOS ay Ze ZE 691 VI Ld AQSZ UOLP A0SZ UOLP von L ugL EE dE EZE9NI AEE LSO Io oU 8sH o za ZO su z Z0SLSS BE gt Sng8l LOWL era YZO6ZNZ xne M2 gt TV 6l P LPNL E S wt SON i goggy CONS 089 y YZZZZNZ sza AZZ V or LcNL ZSY 229 SL S 3001 aga via xneA Q2 zs zung Tel c A09 L ZUb AOS ngL uoo u00 9n 0 EE 910 19 Sd zen s yggezand LEE nens nen ined T A CU FUND 939 SCH A S2 U0LV ASZ gei ASL LV SH SNX3Y Odvul LHL g13 RX14_GEKKO_SEDv5 0_9au Page 50 EuROLAUNCH If an overload or a short circuit occurs on any output the other output vol
18. Enter standby mode POWER ON INIT device e MEAS enabled SEND STORE frame y Reset FRAME RDY Measure next point Frame ready LO set Y Wi a Set FRAME RDY Send LO detected Last point SEND STORE frame y Reset FRAME RDY ETE ER TET EU i M M M M M M SOE set a y Collect HK data ie HK FRAME RDY n Nominal operation enable MEAS SEND STORE frame FRAME Hecode TE Reset FRAME RDY ED RDY START W IEE f enable MEAS t Hun test In eim orv Enter standby operation disable MEAS Erase post operation Download memory SEND STORE frame Losses Reset FRAME RDY Figure 31 On board software flowchart In nominal mode the experiment shall take the measurements in predefined bias voltage ranges The bias voltage steps AU ias are the same within one characteristic so each sweep can be defined by the start value Upiaso l and step AUpias I These data are stored in the EEPROM of the PIC RX14 GEKKO SEDv5 0 9aug13 Page 64 EUuROLAUNCH When a timer interrupt occurs in nominal mode the OBDH shall take four AD conversion and two DA conversion to collect one one point of the actual characteristic The transient time of the precision amplifier is in the order of the AD conversion time so the voltage adjustment cannot be followed by the current reading on
19. Table 33 Experiment preparation activities Day 1 Task Responsible Task Responsible required time required time Check the attachment of the Gerdien O L rinczi Set up Ground G Balassa condensers visual checking 10 mins Station 20 mins Place the protective covering onto the O Lorinczi Prepare Gekko G Balassa edges of the condensers GSE 20 mins Remind other experimenters to pay Zs Varadi attention of the HV system 10 mins Check the mounting of the Electronic O L rinczi box to the module visual checking 10 mins Connect the electronic box to the Zs V radi Gerdien condensers 10 mins Connect the Gekko GSE to the Zs V radi electronic box through the 10 mins technological connector Perform functional tests on the Zs V radi experiment and ground station G Balassa 1 hour Upload on board memory content Zs V radi bias voltage value if necessary G Balassa optional 1 hour Upload the OBDH software update if G Balassa necessary optional 1 hour Remove technological connector Zs V radi 10 mins Connect the experiment interface Zs V radi connector to the electronic box 10 mins RX14 GEKKO SEDv5 0 9aug13 Page 117 EuROLAUNCH Table 34 Flight Simulation Test activities Task Responsible required time FST 30mins Set up Ground Station G Balassa Start Ground Software 15 mins Monitor telemetry data on the ground Zs V radi station G Balassa Set the experiment operational mode G
20. a very popular coax connector with threaded coupling and can be used up to frequencies of over 18 GHz depending on type The impedance is controlled at 50 O Connector styles are available for flexible conformable and semi rigid cable types Versions of the SMA connector are available for mounting to printed circuit boards using both through hole soldered and through hole press fit techniques as well as surface mount types SMD Solder crimp and clamp techniques are used to terminate this series to cables SMA applications include communications satellite and test equipment 2013 Telegartner Karl Gartner GmbH Technische Anderungen vorbehalten Technical changes reserved www telegaertner com Lerchenstr 35 D 71144 Steinenbronn Tel 49 0 7157 125 100 Fax 49 0 7157 125 120 E Mail info telegaertner com RX14 GEKKO SEDv5 0 9aug13 Page 176 EUROLAUNCH A DLR and SSC cooperation Habia Cable RG 316 U 50 Ohm Coaxial Cable Construction Alternatives Construction mm Acc to M17 138 00001 Conductor Silver plated copper covered steel 7x0 17 0 51 PFA jacket Dielectric Solid PTFE 1 52 Specified SRL limits i Silver plated copper 0 10 2 05 FEP White 2 50 Acc to M17 113 RG 316 FEP jacket Transparent i 15 kg km Specified SRL limits Speedflex 316 Low Smoke Zero Halogen Alternative jacket colours also available Technical Data Attenuation amp Power Impedance Capacitance Velocity of signal pr
21. assure turbulence free airflow a defined distance has to be present between the rocket wall and the condensers as there is a turbulent boundary layer near the rocket The thickness of the boundary layer is dependant of the distance measured from the tip of the rocket therefore the necessary condenser distance varies in relation to the placement In chapter 5 3 the needed distances are available in case of mounting the condensers at the top or at the base of the payload The electronics box The raw material of the electronics box is the STANAL 40 aluminium alloy We use bolted connections in order to achieve easy mounting and proper fixation at the same time All bolts fixing the box walls are the size of M3 for mounting the electronics box to the bulkhead we use six pieces of M4 bolts In the electronics box there are four PCBs e Power supply PCB e On board data handling PCB e Measurement Signal amplifier analogue PCB e Motherboard At the sides of the electronics box grooves are designed to encase the PCBs equipped with the card lock retainers At the inner end of the electronics box there is room for the motherboard at the top of the electronics box the wires and cabling can be placed RX14 GEKKO SEDv5 0 9aug13 Page 46 EuROLAUNCH The connector interfaces are placed on the top of the electronics box if there is not enough height for the connectors these might be placed on the upper region of the front side Fig
22. condensers If the velocity is lower we can decrease the voltage and the experiment becomes safer Figure 46 Airflow velocity in a cross section of the condenser As the results show the airflow velocity inside the condenser is much slower than the undisturbed flow The value changes between 0 8 1 2 Mach that is similar to the estimation given by the experts from DLR RX14 GEKKO SEDv5 0 9aug13 Page 92 EUuROLAUNCH 1275 58 1148 82 1021 27 883 507 765 949 638 791 510 633 382 975 255 316 127 658 D Velocity m s Figure 47 Airflow velocity and trajectories It is important to emphasize that in this case the boundary conditions represents the properties of the atmosphere near to the surface Assuming higher altitudes the atmosphere and the airflow characteristics might show great differences RX14 GEKKO SEDv5 0 9aug13 Page 93 EUuROLAUNCH Boundary layer The calculation of the accurate flow profile is possible by solving a Navier otokes equation but this is not necessary as our goal is to determine the thickness of the boundary layer mM LL _ nee ee o amem er ht TT ae um Figure 48 Heat flux distribution of the condenser Determining the thickness of the boundary layer The thickness of the boundary layer is a distance measured from the wall where the velocity of the flow reaches 99 o
23. correct The condensers and their mountings can withstand without damage under the vibration test is carried out in accordance with the requirements of the rocket Table 19 Vacuum test Electronics box Test facility Vacuum chamber at BUTE Tested item Electronic box Test level procedure System level 15mins and duration Verified Requirement D7 The test objectives This test is to verify that the experiment withstands the REXUS pressure environment The primary goal of this test is to recognize possible coronal effects inside the electronic box During this test the experiment operates in normal operational mode under 1mbar pressure Table 20 Vacuum test Gerdien condensers Test type Vacuum test Test facility Vacuum chamber at BUTE Tested item Gerdien condensers Test level procedure Unit level 2mins and duration RX14 GEKKO SEDv5 0 9aug13 Page 6 EUuROLAUNCH Verified Requirement D7 The test objectives This test is to verify that the high voltage doesn t cause coronal effects on the Gerdien condensers The test is performed under 1mbar air pressure Table 21 RF Test Test number 12 RF anechoic chamber at BUTE Tested item Whole experiment Test level procedure System level and duration Verified Requirement The test objectives This test is performed to measure the effects of the RXSM o band transmitter on the experiment The test is made in an RF anechoic chamber with an S band
24. for the bias amplifiers Table 6 shows the nominal voltages and currents for each output 28 V bus from RXSM maximal 28V 110 3000 input current limited E 250 mA 28V Ground Analog supply for current sensor amplifier of gerdien condenser 1 Analog supply for current sensor amplifier of gerdien condenser 2 Supply for bias generator preamplifiers Table 6 Power supply voltages and planned nominal loads The A1 and A2 outputs are galvanically isolated from the others GND 3 GND 4 AN GND and D GND are connected to the 28V Ground on the motherboard see figure 10 GND 1 and GND 2 is connected to the output of the bias amplifiers see figure 16 in chapter 4 5 2 The primary side of the power supply is designed to be capable of delivering at least 3 W of power for the transformer in all circumstances even though the load on the secondaries will obviously not exceed 1 W The circuit diagram of the complete power supply unit can be found on the next page RX14 GEKKO SEDv5 0 9aug13 Page 49 A DLR and SSC cooperation EUROLAUNCH T T naaus 99 0 0 GT 9B ZTOZ eYeQ GUNN iusunoog bEA ADEGATE snxaasnx3 PS 111L AlddNS YsMOd 041419 ao an9a A E GND UL 9 2 Say GND L_y A S IS ECW IX QNS su je L2O 1X GAZT SV GAZ SV E gy ayo H aN9Y u zayo 4 Age
25. in previous lectures check the team site What happens if the HV short circuits Be careful with overload protection RX14 GEKKO SEDv5 0 9aug13 o Thermal SEC o O Software SEC o EUROLARUNC Page 149 N A DLR and SSC cooperation It is not clear how the rocket is insulated from the 240V Please include this Use filtering to filter S Band this should also be included in your development test On the input to the RX you need 1k not 120ohm check the user manual for more details Remove the crystal oscillator from the schematic Include some calculations about drift based on assume initial velocity Co axial cable connections should be clear especially if they can and should be removed during testing integration A lot of GNDs come up with a clear grounding concept Pg 40 two inputs from the condensers one back tracks on the positive but the one on the bottom is disconnected check this Be careful with the PCB design specifically filtering and grounding You should repeat the thermal analysis on the condensers following the redesign with correct boundary conditions It seems you were incorrectly informed on the temperature for this please ask for advice if you need it Consider the use of thermal ablation material Consider the effects of aerodynamic heating see thermal you may need to include coatings in this section With regards to aerodynamic heating please be careful w
26. latitudes where galactic cosmic rays participate in greater degree in ionization processes This means that not only particles of greater penetrating depth considering the lower ionosphere but also greater fluxes due to the decrease of magnetic rigidity should be considered The polar cap where measurements will be carried out is also a special location from the point of view of ionization taking into account the direct connection partly to the tail of the magnetosphere partly to the interplanetary space Therefore it is suitable to monitor from time to time the state of the atmosphere at greater altitudes and at high latitudes as well RX14 GEKKO SEDv5 0 9aug13 Page 6 EUuROLAUNCH 1 INTRODUCTION 1 1 Scientific Technical Background Our scientific objective is to study the composition of ionized molecules in different altitudes of the atmosphere An applicable tool for this purpose is a Gerdien condenser 8 because it is designed to measure the ion mobility spectra of various molecules The composition and the variation of the composition of the atmosphere is a very important question since the concentration of harmful gases is increasing For example the greenhouse gases are produced at the surface of the Earth but they are transported to higher layers by diffusion and chemical reactions 9 It is also interesting to compare our results with previous measurements and methods 10 Figure 1 Nosecone mounted Gerdien cond
27. negative bias amplifiers RX14 GEKKO SEDv5 0 9aug13 Page 109 EUuROLAUNCH The LO and SOE control circuits were also tested on room temperature and 20 C as well OBDH board We have built a qualification model of the Gekko OBDH that was tested in thermal chamber Test 4 This model was also used for software development and testing The design of the flight model was initiated after the final board level tests of the qualification model 5 3 6 System level tests We made several tests with the whole experiment to verify the following requirements F 2 F 3 F 5 F 7 D 10 D 12 OT O 4 O 7 The next picture was taken on the integration week Figure 61 Performing a system level test integration week DLR Bremen The experiment was connected to the Gekko GSE which supplied power to the experiment and provided communication IF The following table shows a set of HK data after a test run RX14 GEKKO SEDv5 0 9aug13 Page 110 EuROLAUNCH V V V mA C V V 72 70 28 02 2489 2161 516 51 7263 28 06 2486 2161 Sg 51 72 6 51 72 6 51 RX14 GEKKO SEDv5 0 9aug13 Page 111 EuROLAUNCH 5 3 Vacuum test The aim of the vacuum test Test 10 11 is to looking for corona effect caused by the high voltage system Ihe electronics box was tested in a vacuum chamber at the university This test was performed without the condensers WT Las XL Figure 62 a vacuum test university Figure 62
28. of the REXUS The experiment thermal dissipation must not A A heat up the outer structure more than 10 C over the ambient temperature The experiment thermal dissipation must not A 4 heat up the parts close to or in contact with the feed through cable more than 70 C y R T R T R T R T R T N The experiment thermal dissipation must not 9 heat up parts facing other modules more than 50 C The heat transport by convection must be A limited in such a way that the air temperature at the module interfaces does not exceed the ambient temperature by more than 10 C RX14 GEKKO SEDv5 0 9aug13 w Page 70 EuROLAUNCH ume TT under 1mbar air pressure EJ MN NNNM RXSM experiment interface EJ NN NN D SUB 15 male type 3 5 1 T NN A on the RS422 telemetry interface D io NN D 11 30kbps Deelen RXSM power interface The experiment shall be able to operate from R T D 13 the RXSM power line in the range of 24V to 36V supply voltage C MN NN D 14 exceed 3A BER experiment shall not exceed 1A 3 55 NN power line shall be less than 500mV D NN NN laminar 40mm from the outer surface of the rocket non volatile memory to store the entire data The experiment shall not resonate during the A flight the eigenfrequency of the experiment c 00 O o NO units shall highly exceed the frequency of rocket vibration during flig
29. on the required mechanical changes Following the above submission a further submission of version 2 3 covering all the points in this report specifically safety and chapter 6 is strongly recommend for submission by the 5 of August o Version 3 0 will be due in around the 27 of August TBC RX14 GEKKO SEDv5 0 9aug13 REXUS Pus m Experiment Integration Progress Review EvroLaur INCH Page 1 REVIEW Flight RX 14 Payload Manager Mikael Inga Experiment GEKKO Review location Budapest Hungary Date 040ct2012 Review Panel Mikael Inga SSC Experiment Team members Ott Botond L rinczi Vilmos Gor cz Cooperating visitor Andr s Fut Veronika Gr sz Cooperating visitor B lint Kollek J zsef Szab Endorsing professor Adri n Gugyin Antal B nfalvi Endorsing professor Zsolt V radi G bor Kocsis Endorsing professor PICTURES on Ai re i o m a EA e Uc e 1 TM L gt ee nan ay Se c f OBDH Components RX14 GEKKO SEDv5 0 9aug13 Page 152 EuROLAUNCH REXUS Experiment Integration Progress Review EuroLAUNCH Page 2 Amplifier board Power supply board GENERAL COMMENTS e The major concerns are about the condensers design outside the module PANEL COMMENTS AND RECOMMENDATIONS Science e Measurements from LO up to approx 75km altitude maybe delay nose cone ejection to avoid disturbing measurements e How to test calibrate condensers e Wind tunnel m
30. payload after the recovery RX14 GEKKO SEDv5 0 9aug13 Page 125 EuROLAUNCH A DLR and SSC coop Figure 47 After payload recovery The first inspection revealed that the sensors were filled with snow the tip insulation rings were deformed melted and some burning smell leaked from the experiment modules After the experts disassembled the payload they found a lot of soldering tin inside the Gekko module and some tin inside the Caesar module The following pictures were taken when we started the inspection and analysis after the recovery of the Gekko module RX14 GEKKO SEDv5 0 9aug13 Page 126 EUROLAUNCH A DLR and SSC cooperation Figure 49 The attachment of the triaxial cables are damaged RX14 GEKKO SEDv5 0 9aug13 Page 127 EuROLAUNCH Figure 50 Insulation ring melted during the flight We recognized that the cable attachments were damaged the two shielding layer of the triaxial cable were shorted and the soldering tin of the triaxial cable was melted and sprayed into the module Most of the tin was deposited on those sides of the electronics box that were facing to the sensor attachment and on the wall of the experiment module Figure 48 The impedance of the experiment power line was checked through the experiment IF cable by a multimeter There was no short circuit on the power line According to the study and calculations of our physicist the unexpected high temperature w
31. phase At this time the HK data collection is still running but the condensers are not biased there is no electrical field in the pipes During the countdown the experiment goes through the processes without any intervention The operational modes of the OBDH software are shown on Figure 30 RX14 GEKKO SEDv5 0 9aug13 Page 61 EUROLAUNCH A DLR and SSC cooperation Not performed Auto TC TC Auto TC Auto during a hot CD Poweron Auto Reached by TC only TC SOE Part of the normal process Figure 30 On board software state diagram When nominal operation is performed the program adjusts the bias voltage in a predefined voltage range and measures the condenser current and the bias voltage as well After 4 current and 4 bias voltage measurements were done with both condensers a data frame is formed transmitted to the ground station and stored into the onboard memory Every frame contains 16 measurement data including 2x4 current and 2x4 bias voltage measurements as shown below Experiment data frame emm SYNC WORD FRAME CNT mE ior TIME STAMP PARITY PL TM Sizeteytes 2 2 NENNEN ee E Ce EEN where PAYLOAD DATA Data byte 12 Cal 56 T8 LI aan Lan V GC bias 1 C GC141 V_GC2bias 1 C GC2 4 V GC2bias 4 C GC2 4 In nominal mode the measurement and the serial communication performed in parallel The transmission of a single data frame starts with the sy
32. small the mean free path will be large and if the pressure is high the mean free path will be small and less energy can ionize molecules Requirement 1 The mean free path has to be less or equal than the distance between the inner and the outer electrode otherwise the air cannot be considered continuum Now the average ion drift speed shall be defined To do this we use the Maxwellian speed distribution by means the speed distribution in different altitudes can be determined The average speed is Kai 1 1 8 NT v Substituting the results obtained from Einteins equation 2pd n mm Thus the mobility of ions is inversely proportional to the square root of the mass of the ion which means that it is more difficult to accelerate an ion of more mass with the same electric field Now we describe the measuring method we use The mobility spectrum of the ions is determined by measuring the condenser current and some knowledge of the atmosphere is also needed These are the ion mobility in different altitudes the speed of the rocket the ion density the temperature pressure and so on The speed in different altitudes is given before the flight by EuroLaunch and the temperature pressure and the neutral particle density not ion density can be calculated by atmosphere models Figure 1 shows a sketch of the condenser RX14 GEKKO SEDv5 0 9aug13 Page 10 EuROLAUNCH L Figure 2 The Gerdien condens
33. speed temperature and the height The plot buttons are to draw diagrams of the related measurements In the communication history window we will see the main steps of the measurement for example communication is ready port is opened error occurred and so on RX14 GEKKO SEDv5 0 9aug13 Page 68 EuROLAUNCH A DLR and SSC coop 5 EXPERIMENT VERIFICATION AND TESTING 5 1 Verification Matrix Table 9 Verification table TTT TT n The experiment shall measure the ion mobility A F 1 during the flight of the rocket using two Gerdien condensers The experiment shall adjust the bias voltage of R T F 2 the Gerdien condensers according to the velocity of the rocket Dr mater Tol the Gerdien condensers 7 LA electronics EJ coc current and input voltage of the PSU into an on board non volatile memory The experiment shall send the data to the R T F 7 ground station through the RXSM during the whole flight of the rocket The ion mobility measurements shall be performed between 0 005 and 15 m Vs for The experiment shall use its own PSU to F 4 ensure continuous power supply for the EF C EF positive ions and from 0 01 to 20 m Vs for negative ions P 1 The ion mobility measurements shall be A performed with an accuracy of 0 001 m Vs NE for both positive and negative ions The ion mobility measurements shall be P 3 performed at a rate of 128 measurements Ions
34. time and money Its better to order the components or at least check the availability at the distributor before initiating the PCB production Different manufacturers can use different footprints for the components Using a common software environment within the team we have lost some time and made some mistakes with converting or re drawing the schematics that were made with different software by different team members RX14 GEKKO SEDv5 0 9aug13 Page 137 EuROLAUNCH 8 ABBREVIATIONS AND REFERENCES 8 1 Abbreviations This section contains a list of all abbreviations used in the document Add abbreviations to the list below as appropriate In version 5 of the SED final version delete unused abbreviations AIT asap BO BR CDR COG CRP DLR EAT EAR ECTS EIT EPM ESA Esrange ESTEC ESW FAR FCL FST FRP FRR GSE HK HV HAN ICD I F IPR LO LT LOS Assembly Integration and Test as soon as possible Bonn DLR German Space Agency Bremen DLR Institute of Soace Systems Critical Design Review Centre of gravity Campaign Requirement Plan Deutsches Zentrum fur Luft und Raumfahrt Experiment Acceptance Test Experiment Acceptance Review European Credit Transfer System Electrical Interface Test Esrange Project Manager European Space Agency Esrange Space Center European Space Research and Technology Centre ESA NL Experiment Selection Workshop Flight Acceptance Review Foldback Current Limiter Fl
35. transmitter operating with TBD dBm power To see the direction dependence a rotator platform is used Table 22 Wind tunnel test Test facility Tested item Gerdien condensers Test level procedure Unit level Acceptance test and duration Test campaign duration 1 day Verified Requirement D1 D17 The test objectives This test is to verify the design performance of Gerdien condenser by the measurement of the physical parameters Component tests are performed after the procurement before the board population Test facilities are the multimeters and characterispcope RX14 GEKKO SEDv5 0 9aug13 Page E UROLAUNCH 5 3 Test Results 5 3 1 Mechanical stress and vibration analysis and test Verification of Reg D 1 and D 20 The experiment will be designed to withstand all loads due to acceleration and vibrations Verification can be carried out by finite element method analysis regarding the material selection results Vibration simulation and test is also feasible in the lab An additional goal of the vibration test is to prove that the experiment will not resonate during the flight To ensure this the eigenfrequency of the experiment units should highly exceed the frequency of rocket vibration during flight Based on an ANSYS modal analysis this requirement is fulfilled the first results can be seen below Figure 33 ANSYS model geometry RX14 GEKKO SEDv5 0 9aug13 Page 8 EuROLAUNCH 6 1890 4
36. 013 on board the REXUS 14 sounding rocket The scientific background and the objectives are described and the engineering considerations are also discussed The document contains the detailed mechanical and electrical design of the payload as well as the project management aspects and the outreach approach of the team The flight results and the conclusion of the post flight analysis are also included Abstract REXUS Gerdien condenser polar region sounding rocket ion composition precision current measurement Space research Keywords RX14 GEKKO SEDv5 0 9aug13 CONTENTS ABSTRACT e HOUR 5 1 INTRODUCTION EE 6 1 1 Scientific Technical Background 6 1 2 Experiment EECHER eege e 14 1 3 Experiment Overview mmm 14 E SAMSA TS az TUNNEL 16 tAr CONGCEFON ne een EET 16 1 4 2 Team RE EE 16 2 EXPERIMENT REQUIREMENT S EE 18 ZA TUNCUIONAlLIRSOUNCITISINS eiecti 18 2 2 Performance reourements 19 29 DESIOM REQUIFCINISING EE 20 2 4 Operational Requirements s ssssssssssssssssss sss zzz 22 3 min 93cm EIC 23 3 1 Work Breakdown Structure VV 23 MERI le 25 Se EN Elei EEN 25 S22 DUGO Tm 26 329 Eer E 6 6 610 dE 26 3 3 Outreach leote T TT 27 S bic dace E LE E UU UU UU EETTM 30 4 EXPERIMENT DESCRIPTION EE 32 41 EIERE SIUD gege 32 4 2 Experiment Interfaces 2 0 0 0 cccccc ceca sec eeeaeeceeeeeeneeeeeeseeeeeeneeneeeaees 34 e GN ent Lu er E 34 BZ EEE TE MR TUUM M 37 4
37. 100 Fax 49 0 7157 125 120 E Mail info telegaertner com RX14 GEKKO SEDv5 0 9aug13 Precision amplifier BURR BROWN E Page 179 EUROLAUNCH A DLR and SSC cooperation OPA124 Low Noise Precision Difet OPERATIONAL AMPLIFIER FEATURES LOW NOISE 6nVHz 10kHz e LOW BIAS CURRENT 1pA max e LOW OFFSET 250uV max LOW DRIFT 2uV C max e HIGH OPEN LOOP GAIN 120dB min e HIGH COMMON MODE REJECTION 100dB min e AVAILABLE IN 8 PIN PLASTIC DIP AND 8 PIN SOIC PACKAGES DESCRIPTION The OPA124 is a precision monolithic FET opera tional amplifier using a Difet dielectrical isolation manufacturing process Outstanding DC and AC per formance characteristics allow its use in the most critical instrumentation applications Bias current noise voltage offset drift open loop gam common mode rejection and power supply re jection are superior to BIFET and CMOS amplifiers Difet fabncation achieves extremely low input bias currents without compromising input voltage noise performance Low input bias current is maintained over a wide input common mode voltage range with unique cascode circuitry This cascode design also allows high precision input specifications and reduced susceptibility to flicker noise Laser trimming of thin film resistors gives very low offset and drift Compared to the popular OPA111 the OPA124 gives comparable performance and 15 available i in an pin PDIP and Son SOIC package
38. 1750 1500 1250 1000 750 500 250 0 1 2 3 4 5 5 Figure 34 Natural frequencies of the condensers x order y frequency As seen on figure 34 the 6 mode is the highest frequency below 2000 Hz thus there is no need to analyze higher modes The eigenfrequencies are as follows Table 23 Eigenfrequencies mode a ur ber bor Frequency 568 24 156942 1145 9 15344 1535 4 1890 Hz RX14 GEKKO SEDv5 0 9aug13 Page 79 EUROLAUNCH A DLR and SSC cooperation To ensure that the calculated eigenfrequencies are correct the frequency response diagrams bode have to be determined for the condensers The results can be seen below 5 57 e 4 2 b4e 4 1 26e 4 595e43 2 83e 3 Amplitude Pa 1 34e 3 638 303 144 30 250 500 750 1e 3 1 25e 3 L ps 2e 3 Frequency Hz Figure 35 Frequency response z axis The local maximum on the diagram is at 570 Hz RX14 GEKKO SEDv5 0 9aug13 Page 80 EUROLAUNCH A DLR and SSC cooperation 265e 5 1 02e 5 3 66e 4 1 31e 4 itude Pa l4 7 amp 3 Ampl 1 68e 3 603 I 216 77 4 30 250 500 750 le 3 1 25e 3 L ps 2 83 Frequency Hz Figure 36 Frequency response y axis The local maxima on the diagram are at 5 0 Hz and 1150 Hz 2878 3 1 95e43 1 33813 LE cC Lu Amplitude Pa e H I JI nan Ki E 284 193 131 30 250 500 750 Lle 3 1 25e 3 1 5e 3 2e 3 Frequency Hz Figure 37
39. 3 Experiment COMPOMGIUS iuste geen 40 44 Me cnanical len UU UU MTM 43 A S Electronics DeSlgli genee eege ebe pairs peccet ndo 47 4 5 1 Power Supply X Db diii dodo eI emt imeem etie oreet 47 4 5 2 Analogue electronic boer 50 4 5 3 Digital electronics ede E EPI DEINER DU 54 fg bn E UL EE 58 Al Se OW Gl Dy SUS METTE mmm 59 4 9 SOWAS Re e DEEN 60 4 9 Ground Support Eoumpment ccc ccc cece eee e eee eeaeeeeeeeeeaeeeeenees 65 5 EXPERIMENT VERIFICATION AND TESTING 68 S1 Venicaton I AU E 68 RX14 GEKKO SEDv5 0 9aug13 D2 EA el ad ee TUS 11 9 9 KEE 7 5 3 1 Mechanical stress and vibration analysis and test 17 5 3 2 Thermal simulation of the condensers 89 5 3 3 FEM analysis of atlow cece cece ceca cece seen seen eeeeeeeeenas 91 9 3 4 Calculations on the effect of roll during flight 99 5 3 5 Electronics Board level tests 102 5 3 6 System level tests cc cccccsccceecsseeeesececeeeseesseeeeeeseess 109 Sif WAC IN Ie S osse Dun CRDI CIPUE Es dab Dein 111 LAUNGHIGAMPAIGNPIRSEPAISATION 6 istituto bibend 113 6 1 Input for the Campaign Flight Requirement Plans 113 6 1 1 DIMENSIONS and maes ern 113 5 12 tele eege 113 6 1 3 Electrical ae 114 6 1 4 Launch Site Heouements 115 6 2 Preparation and Test Activities at Esrange 115 6 2 1 Handling o
40. 5 uL nmm RR 5 355 __ 5 940 pg Se Table 30 PSU bread board model static tests Note that the PSU breadboard model test was done with the old 120V output transformer The next figures show the results of the PSU flight model board level test that was performed on room temperature RX14 GEKKO SEDv5 0 9aug13 Page 103 EUROLAUNCH A DLR and SSC cooperation e Uin 24V Uin 28V o Uin 36V Figure 51 Input current limiter of the PSU 20 478 im 276 3 C PS IN l Scale factor 25 368 AN 60V V AN 60 AN 60 1 6 Scale factor 42 469 5 258 1 767 2 9757 5 264 2 9841 145 1177 o 145 1178 256 243 o 255 238 568 63 Figure 52 Define the scale factors for HK data processing RX14 GEKKO SEDv5 0 9aug13 Page 104 EuroLAUNcH A DLR and SSC cooperation Amplifier board Several functional tests were performed on the breadboard model of the analogue electronics before we started the PCB design The next figures show the results of the performance tests that were made with the flight model PCB E e e e AMP 10G6 LA VD e e regression line10G LA EA CH e m E ei m E E 8 10 15 Condenser current pA Figure 53 Characteristic of the precision amplifier 0 20pA p IK ce ce AMP OUT 1G Reg Line 0 6nA Output voltage mV o D CH a a a e AMP OUT 100M q ce e 1000 2000 3000 4000 5000 6000
41. 5 0 9aug13 Page 21 EuROLAUNCH The experiment shall be able to operate from the D 13 RXSM power line in the range of 24V to 36V supply voltage The inrush current of the experiment shall not exceed 3A The continuous input supply current of the experiment shall not exceed 1A D1 The voltage ripple fed back to RXSM over the power line shall be less than 500mV 47 The airflow of the Gerdien condensers shall be laminar The Gerdien condensers shall be placed 40mm from the outer surface of the rocket The experiment shall be equipped with enough non volatile memory to store the entire data The experiment shall not resonate during the flight the eigenfrequency of the experiment units shall highly exceed the frequency of rocket vibration during flight The shift caused by the roll of the rocket shall not disturb the measurement RX14 GEKKO SEDv5 0 9aug13 Page 22 EuROLAUNCH 2 4 Operational Requirements The experiment shall be able to conduct O 1 measurements autonomously in case connection with the ground segment is lost The bias voltage values shall be calculated O 2 according to the predicted flight profile before the flight The calculated bias voltage values shall be O 3 uploaded into the onboard non volatile memory before the flight KC The start of the measurement shall be triggered by O 4 the LO control signal The onboard memory pointer shall be s
42. 6 this should be a standalone chapter If you have to repeat other sections here that is OK o In your timeline and design power on should be at T 600s not T 1200 Organisation project planning amp outreach hapters 3 1 amp 3 o With your resource manpower allocation it is iol dran how the percentages work use man hours if you can or make it clear what the percentages mean Make the role of the backups clear Include a more detailed budget in the SED Add URL for your Facebook page and website on the outreach chapter Post more on Facebook page try drum up more likes Update your website your latest news at the moment is the PDR Update the latest milestones on the website Add all new team members on the team member list be sure to include them on join space too Add pictures to the gallery on the website Include all the sponsors logos on the website 5 Internal Panel Discussion Summary of main actions for the experiment team o Correct all the comments in this report specially consider the points in safety and chapter 6 o Provide an updated SED with the required mechanical changes in full CDR Result conditional pass Next SED version due o Provide an updated mechanical section in version 2 2 ASAP for review by the panel the deadline for this is 4pm on Thursday 19 of July The experts will then decide whether the new design is suitable and whether you can fully pass the CDR For this update concentrate
43. 7 9 March 2013 Kecskem t Hungary Zsolt V radi REXUS Gekko Why to put a steel pipe on a rocket Hungarian presentation in the Europian Space Expo 23 March 2013 Budapest Electronic publications Zsolt V radi Hungarian experiment in the ESA REXUS rocket programme Publication at the U rvil g Hungarian space research related web portal Hungarian Radio Interview We gave an interview to a Hungarian radio Klubr di together with the BEXUS BioDos team n the 30 minutes scientific entertaining programme we talked about the background RX14 GEKKO SEDv5 0 9aug13 Page 29 EUuROLAUNCH and the objectives of the Gekko experiment gave the audience an introduction to the REXUS BEXUS programme and also brought up topics like the importance of such projects the benefits for the participating students and the fun parts of the mission RX14 GEKKO SEDv5 0 9aug13 3 4 Risk Register Table 3 Risk Register Risk amp consequence if not obvious SF10 SF11 SF20 SF21 SF30 SF40 SF50 MS10 MS20 ow Due to improper aerodynamic design the Gerdien condensers attached to the outer structure modify the planned flight profile of the rocket Residual of SF10 One or both of the condensers breaks off of the structure of the rocket thus modifying the flight trajectory Residual of SF20 Health hazard caused by touching the HV parts of the system Condenser struts may a
44. 9 male female connectors an RS232 2 USB converter a technology IF cable assembled with DSUB 25 male female connectors two power cables with banana plugs a laptop with the installed ground station SW installed MPLAB to re compile the on board SW if necessary USB A to mini USB converter connect PICkit3 PICkit3 programmer and debugger During the pre flight tests the experiment is connected to a laptop Commands are sent to the experiment and the HK and measurement data are received and processed with the GSE software written in C language RX14 GEKKO SEDv5 0 9aug13 Page 66 EUROLAUNCH A DLR and SSC cooperation Figure 32 Gekko GSE service module All measurement and telemetry data will be stored and monitored during the flight A picture of the program is shown in Figure 32 HS Gekko Ground Station te mie t hist S Port opened at 2012 12 16 22 45 05 HKkfiuwneurvwhuivhwevnwuvthwiuvnHKnvwrurenwiruhfuishveunjsdfh vusdfhvsdfuhuhvkHKhuimwebncghwghcwghfiuhwiuvhHKnuicvwniuwc vibirubvwrivzbiubwibvziwrvzbAB vurn unvsujoihjgrosjvunruvnsonvsunvusn Stop Open Port Close Port Telecommands ENETCENN Y Axis 10 3 Figure 32 Ground Software user interface RX14 GEKKO SEDv5 0 9aug13 Page 67 EuROLAUNCH The main sections of the ground station SW are the serial port communication telemetry telecommands and measurements There is also another section which shows the elapsed time
45. Amplifier e P 4 changed 10mV to4 50V e P 9 changed PSU shall provide 15 V and 60V RX14 GEKKO SEDv5 0 9aug13 Page 157 EUROLAUNCH A DLR and SSC cooperation x REXUS e Experiment Acceptance Review U ROLAUNCH Page 3 e Engineering model OBDH tested in thermal chamber e Flight model PCB OBDH successfully performed functional tests e PSU breadboard functional tests successful e Components same as BloDoS therefore tested Thermal SED chapter 4 2 4 amp 4 6 e OBDH board tested see above e PSU and amplifier not tested due to failure of test chamber e Alternative test chambers are available Software SED chapter 4 8 e Software ready in parts data acquisition structure in memory needs to be otpimized e Only working on a lower Baud rate Verification and testing SED chapter 5 e vacuum test will be done after integration at the university 1 20 mbar e vibration test after integration at EL TECH facility e wind tunnel test skipped due to lack of wind tunnel airflow simulation made instead Safety and risk analysis SED chapter 3 4 e no comments Launch and operations SED chapter 6 e Section 6 4 will be updated until end of January 2013 Organisation project planning amp outreach SED chapters 3 1 3 2 amp 3 3 e Deadlines will be modified SED e New submission date 16 Dec or later depending on the tests e Section 6 4 will be improved End to end Test e Test with the Simulator was par
46. Balassa manually by sending TC e g from Stand by to Prepare in case of absence of LO signal After FST Set the operational mode into Stand G Balassa Power required on by and reset the mass memory the experiment pointer to its initial value at the end of interface connector the test before power off After FST Remove the protective covers from the O L rinczi condensers 10 mins 6 2 1 Handling of the module While working on the module it can sit on a bench as the length of the condensers is shorter than the height of the module After mounting the condensers the bulkhead brackets can be inserted After mounting the electronics box to the bulkhead it can be inserted into the module from the bottom due to big cable cut outs in the bulkhead that was a request from experts in order to make room for another experiment and optimise the arrangement of the payload The safe handling holding points of the module When carrying the module it would be preferred not to pick it up by the condensers however its mechanical strength is sufficient in case of emergency or in a situation when the module can only be picked up by the main spacers of the condensers The safe handling points are the bottom and top edges of the module RX14 GEKKO SEDv5 0 9aug13 Page 118 EUuROLAUNCH Figure 45 Safe handling points of the Gekko module 6 2 2 HV system description safe handling The HV is generated on the PSU
47. EUROLAUNCH Figure 18 Condenser setup The outer electrode is protected mechanical protection and static shielding by a coating and terminated by screw caps for the fixation of all internal parts Three spacers are used to mount the condenser and keep it far enough from the rocket The spacers are welded to the condenser coating The mechanical loads of the module wall are distributed by use of washers see Figure 11 b The condensers are mounted to the rocket by four M6 bolts 2 each and four MA bolts 2 each Wires to the electrodes can be placed inside the spacers The aim of the additional struts spacers at the extremities of the condensers is to prevent the parachute lines from entangling with the condensers The design of the struts has been developed with the help of DLR experts according to the latest feedback regarding the new design there is no risk of entanglement The spacers at the extremities of the condensers are rounded in order not to damage the parachute lines otherwise the cross section of the spacers is a double wedge shape what is ideal for supersonic flights Figure 19 RX14 GEKKO SEDv5 0 9aug13 Page 45 EUuROLAUNCH Figure 19 Condenser Inlet left and the cross section of the main spacer right For the results of finite element method analysis of the condensers thermal and vibration see chapter 5 3 Laminar airflow in the condensers is another essential aspect for our experiment In order to
48. EUROLAUNCH A DLR and SSC cooperation SED Student Experiment Documentation Document ID RX14_GEKKO_SEDv5 0_2aug13 Mission REXUS 14 Team Name Gekko Experiment Title Measurement of the variation in electric conductivity with altitude Team Name University Student Team Leader Zsolt Varadi BUTE Team Members Gabor Balassa BUTE Andras Futo BUTE Agnes Gubicza BUTE Adrian Gugyin BUTE Balint Kollek BUTE Otto Botond Lorinczi BUTE David Szabo BUTE Milan Trunk BUTE Version Issue Date Document Type Valid from 4 1 09 August 2013 Spec 14 January 2012 Issued by Zsolt Varadi Gabor Balassa Otto B Lorinczi Approved by Payload Manager RX14 GEKKO SEDv5 0 9aug13 Change Record 2008 dec 18 2012 feb 16 2012 jun 14 2012 jul 19 2012 aug 06 2012 aug 17 2012 sep 04 2012 oct 01 2012 oct 12 2012 dec 16 2013 apr 16 2013 08 04 New Version all 1 1 1 3 1 4 2 2 3 4 5 6 7 1 1 3 4 2 1 4 3 4 4 4 6 5 3 6 1 1 1 4 2 2 2 3 1 3 2 3 3 3 4 4 2 4 2 4 5 4 6 4 9 5 2 9 3 6 8 1 1 3 3 4 1 4 4 4 8 6 7 1 3 1 4 3 4 5 2 5 1 1 17955 3 291 4 3 5 3 6 1 62 6 3 Wks 2 22 9 1 OZ 4 1 4 3 4 5 4 8 9 1 5 3 6 2 6 3 dee by Ore OF 4 2 2 4 3 4 5 2 4 5 3 4 8 4 9 5 1 9 3 6 1 6 3 92 15 9 2 egen 159 Blank Book 2010 PDR CDR Pre Campaign Final report This document includes all relevant information about the Gekko experiment launched in 7 May 2
49. Frequency response x axis The local maxima on the diagram are at 1535 Hz and 1890 Hz RX14 GEKKO SEDv5 0 9aug13 Page 81 EUROLAUNCH A DLR and SSC cooperation 3 00e 4 fife 3 1 33e 3 ba E LA Amplitude Pa i Lu co LA co 1 55 0 286 5 3e 2 30 250 500 750 Les 1 25 amp 43 1 5843 J 6 3 Frequency Hz Figure 38 Frequency response inner electrode z axis The local maxima on the diagram are at 560 Hz 1150 Hz and 1535 Hz RX14 GEKKO SEDv5 0 9aug13 Page 82 EUuROLAUNCH The results of the modal analysis and the freguency response analysis are similar however the 1535 Hz mode turned out to be Irrelevant analysis results confirmed the statement above As the next step the deformation strain and stress have to be checked at the critical freguencies Due to the long time and high amount of needed computation capacity for the FEM analysis the number of tests have to be minimized Table 24 Analysis T Frequency Hz 568 24 569 42 1145 9 1534 4 1535 4 1890 4 Analysis frequency 570 1150 1535 1980 Hz Boundary conditions of the vibration analyses The boundary conditions of the vibration analyses were as follows The outer surface of the 300 mm RX module was a fixed support and the inertial load acceleration was applied for one axis at a time For the x axis 240 m s for y and z axes 130 m s Compared to our plans with just one spacer before the CDR
50. Goldmann Gy ter 3 H1111 postal code Institute Address Budapest Hungary E mail phone 1 4 2 Team Members Gabor Balassa Educational Background Role in the project Expected workload Andras Futo Educational background Role in the project Expected workload Agnes Gubicza Educational Background Role in the project Expected workload Adrian Gugyin Educational Background Role in the project Expected workload Balint Kollek Educational Background Role in the project Expected workload gekko mht bme hu 0036 7 0 601 2471 Zsolt Varadi software Engineering and Physics BSc student scientific background GSE SW development and data evaluation 14 Electrical Engineering MSc student Electronic design Object of thesis work for 10 academic credits 14 Physics MSc student scientific background data evaluation 14 Electrical Engineering BSc student Electronic and software design 14 Electrical Engineering MSc student Electronic design Object of project laboratory for 10 academic credits 14 RX14 GEKKO SEDv5 0 9aug13 Ott Botond L rinczi Educational Background Role in the project Expected workload D vid Szab Educational Background Role in the project Expected workload Milan Trunk Educational Background Role in the project Expected workload Zsolt V radi Educational Background Role in the project Expected workload
51. Pt ttt DGND Pt tt LL DVDD IDGND DGND C5 C6 C7 S 9 10n 50 100n 50 1u 50 22 ee ee IRR 8 Seen eee So E E BEL E CET BE 888 RBO g ro SPM SCK SP SDO SPI2 SDI SPI2 SCK E SPI2 SDO 9 S SPI2 SDO o o o 3 Figure 27 Microcontroller and memory RX14 GEKKO SEDv5 0 9aug13 Page 57 EUROLAUNCH A DLR and SSC cooperation 100n 50 DGND DGND 10n50 MAX3070 GND DGND _100u 100n 50 10n 50 1301 cao on xU cgo AOND AGND a A E C DCs CR A C SIGNAL H pe En 10n 50 100n 50 AGND RD C303 WS AVDD A SE DVDD 100n 50 10n 50 C325 C326 DGND DGND I C307 B 1Q0n 50 7 AGND 1 r 50 C30 C310 AVDD AGND Figure 28 Multiplexers and RS422 IF RX14 GEKKO SEDv5 0 9aug13 Page 58 EuROLAUNCH Figure 29 AD and DA converters 4 6 Thermal Design Thermal Design of the condensers Due to the heat generated by the friction the proper selection of structural and soldering materials is fundamental From the REXUS manual we could get an approximate temperature value over 200 C for the rocket coverage As a result of discussions with DLR experts the temperature is highly dependent on the angle of surface and the airflow There is a reasonable probability of temperatures up to even 500 C Checking the thermal conditions for the condensers we got roughly similar res
52. XUS service module Due to the new calculations of the predicted flight trajectory the on board software update and the individual test were repeated he bench test with the other experiments Space Sailors Caesar and PoleCats was successfully carried out After the final checkout of the experiment modules done by the ESA and EuroLaunch experts the integration of the payload was started The protective covering of the condensers were marked as Remove Before Flight objects On the 4 of May at the Flight Readiness Review the experimenters and payload managers reached the conclusion that the REXUS 13 and 14 rockets are ready for flight 7 2 2 Failure analysis Table 36 Event timeline Experiment power on 1 600 Nominal operation confirmed Calibration test initiated T 300 RX14 GEKKO SEDv5 0 9aug13 Page 124 e EUROLAUNCH A DLR and SSC cooperation T 240 Short circuit on power line The REXUS power protection unit ie switched off the Gekko experiment No data frame was received after lift off According to the flight telemetry of the DLR TM station the input current of the Gekko experiment suddenly increased after lift off The power line protection unit switched off the experiment after a 10msec overload during which the input current reached approximately 20 Amps note the nominal input current of the Gekko is 30mA After payload recovery the following pictures were taken Figure 46 The REXUS14
53. ace emm le Z ser I setg 2 X09 setg I X09 setg CES CA SIOojoeuuoo ebed 3uoi4 s 3 VA m 2 m HHHH H A RSR Eee F A ig e SIS DPA ad id dE dms AVY B osama quo d y H Ce USA szsng WI 2 9 z g 8 SEN f E szsna wia B a E 3 KK G ct OZI WL A w o AA RA E A H NOZI WL A S S EAE WL A A ezt Z ONS Gd Zz iesuepuoo ueTpreg EAE t UND NV ges AS 7 oeinjonijs AS ONS ASt I X1esuepuoo uerpaos5 get AOZT AOZT OZTt ON O 7 O AST ZY 4 Z ONS Re RR AEA C C C C CC C CC CC C CC STI ELE ENNNNNNNNNNNNNNNNNNNNNNN _ Z ONS Le ounce O AST ZW LXXX XXX O AST TW DEE AST TH IS aR RMP d ind ONS T GND Z AST TV HD i y i m preog zeg 20 3eugoW TI DAettpm 7 h A einjonijs Figure 9 Experiment Setup g13 RX14 GEKKO SEDv5 O 9au Page 34 EuROLAUNCH A1 15Vo A2 15Vo A2 15Vo 120V o GND 2 Figure 10 Grounding concept 4 2 Experiment Interfaces 4 2 1 Mechanical Fixation and mounting of the Gerdien condensers The Gerdien condensers will be mounted to the rocket wall by bolted connections with nord lock washers and thread fixer see Figure 11 b We use stainless steel for most of the parts to meet the requirements in relation with high temperature and mechanical loads At the extremities of the condensers additional spacers prev
54. ach condenser 2 x 10 electronic box Experiment expected COG centre of Experiment COG can be adjusted to gravity position coincide with the geometrical centre of the rocket The current mass estimation does not include some parts on the PCBs and the cables needed for the experiment final weigh will slightly increase 6 1 2 Safety risks Due to improper aerodynamic design the Gerdien condensers attached to the outer structure of the rocket modify the planned flight profile of the rocket This risk has been mitigated to acceptable level by active cooperation between the Gekko team Eurolaunch and ESA in the mechanical design One or both of the tube shaped condensers breaks off of the outer structure of the rocket thus modifying the flight trajectory This risk has been mitigated by cooperation with DLR experts The risk probability was reduced by performing the shaker tests see 6 2 1 for proper handling of the condensers Health hazard caused by touching the HV parts of the system In order to reduce the probability of health hazard protective covering is applied on the edges of the condensers see 6 2 2 for safe handling of the HV parts RX14 GEKKO SEDv5 0 9aug13 Page 114 EUuROLAUNCH A DLR and SSC coop 6 1 3 Electrical interfaces Table 32 Electrical interfaces applicable to REXUS REXUS Electrical Interfaces Service module interface required Yes No usually yes Number of service module i
55. arrock H Design of a simple Gerdien condenser for ionospheric D region charged particle density and mobility measurements Penn State University Sci Rep No 433 1975 15 Zsolt V radi Otto Botond L rinczi Gabor Balassa Pal Bencze Rocket borne experiment for the measurement of the variation in electric conductivity with altitude ESA PAC Symposium 2013 RX14 GEKKO SEDv5 0 9aug13 Page 141 EuROLAUNCH APPENDIX A EXPERIMENT REVIEWS REXUS BEXUS Experiment Preliminary Design Review Flight REXUS 14 Payload Manager Mikael Inga Experiment Gekko Location Esrange Kiruna Sweden Date Tue 28 Feb 2012 1 Review Board members Mark Uitendaal SSC Esrange Olle Persson SSC Esrange Hans Henriksson SSC Esrange Mikael Inga SSC Solna Mark Fittock DLR Bremen Martin Siegl DLR Bremen Markus Pinzer DLR MORABA Nils Hoeger DLR MORABA Peter Turner DLR MORABA Alexander Schmidt DLR MORABA ESA Technical Directorate Koen de Beule Chair Natacha Callens ESA Education Office Paul Stevens ESA Education Office Minutes 2 Experiment Team members Zsolt V radi B lint Kollek Ott Larinczi D vid Szab RX14 GEKKO SEDv5 0 9aug13 Page 142 EUuROLAUNCH 3 General Comments SED o The document was generally good however it was noted that the SED was light on mechanical detail suggesting a lack of expertise in this field Please elaborate this section prior to submission of SED v2 0 o The elect
56. as probably the consequence of shockwaves in the tubes 15 oince the air pressure was higher in the pipes than in the module the hot air was able to flow in melt the soldering tin and spread it into the module The plastic insulation on the cables figure 49 yellow material was damaged by the hot airflow which also damaged the PTFE insulation between the shielding layers of the triaxial cables The disassembly of the electronics box was done step by step in order to identify the location of the short circuit Each stage of the disassembly was documented by photos RX14 GEKKO SEDv5 0 9aug13 Page 128 EUROLAUNCH A DLR and SSC cooperation MS H S LL LO d per AMD HEY z s m 7 K wi ES 2 PTUS iN e WE Neen KEE EEEEE das EE AR pee TETEE fa ee Figure 52 Amplifier board and cable assembly undamaged top cover opened RX14 GEKKO SEDv5 0 9aug13 Page 129 EUuROLAUNCH d e w a d 7 ch 4 a ef L1 Figure 53 Box cabling and connector assembly are unbroken There was no extra soldering tin inside the electronics box the cabling was undamaged and the components were on their places The only place on the top panel where the 28V is directly connected to the module is located close to the optocouplers which lay under the cable lugs 28V GND Figure 53 The insulation of the cable lugs figure 53 yellow plastic was undamaged The next two panels
57. b vacuum test university During the tests the experiment was running and the high voltage outputs were monitored by a multimeter The air pressure was decreased to 10mbar and released several times to increase the possibilities of a corona effect The test was repeated at lower pressure 1mbar After the test we analysed the recorded HK data and we didn t find the sign of any corona effect The vacuum test was repeated on the integration week at the DLR with the whole module including the Gerdien condensers as well The experiment was operating during the whole test while the pressure was reduced to 0 3 mbar We monitored th HK data and we also made visual inspection to recognize a possible corona effect This test was performed successful too RX14 GEKKO SEDv5 0 9aug13 Page 112 EuROLAUNCH Figure 63 preparing the vacuum test DLR Oberpfaffenhofen RX14 GEKKO SEDv5 0 9aug13 Page 113 EUuROLAUNCH 6 LAUNCH CAMPAIGN PREPARATION 6 1 Input for the Campaign Flight Requirement Plans 6 1 1 Dimensions and mass Table 31 Experiment mass and volume Experiment mass in kg 1 634 condensers 0 817 kg each 0 826 electronic box 2 460 electronics box amp condensers 8 209 total mass with module bulkhead Experiment dimensions in m 0 065 x 0 025 x 0 028 each condenser 125 x 165 x 105 electronic box Experiment footprint area in m 0 018900 electronics box Experiment volume in m 4 55 x 10 e
58. board and always presented inside the electronic box while the experiment is powered on This means 60V with respect to the RXSM 28V ground The surface of the electronic box is equipotential to the RXSM structure The high voltage is led to the inner electrode of the condensers when a test is performed or during the flight e Since the condensers are connected to the electronic box by coaxial cables the only reachable HV parts are the inner electrodes of the condensers e Note that the HV is not automatically applied when the experiment is powered on it requires a telecommand or LO SOE to start the operation RX14 GEKKO SEDv5 0 9aug13 6 3 Page 119 EUuROLAUNCH The maximum voltage between one of the inner electrodes and the rocket structure outer electrode electronic box is 60V and the voltage between the two inner electrodes can be 120V in worst case Protective covering shall be used on the edges of the condensers to avoid touching the inner electrodes These covering shall be removed after the final test The experiment shall be powered off when the top cover of the electronic box is open After powering off the experiment the condensers discharges in less than 1s and the module is safe to handle Timeline for countdown and flight The flight will be followed through the Ground Station by G bor Balassa and Zsolt V radi Other team members may join TBC e 30min Turn on the Ground Station computers
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60. ce the bias voltage calculations are based on estimations for the control of the results an extra sweep is also performed after each calculated sweep to cover the full bias voltage range thus extending the mobility spectrum All of the measured data including the condenser currents and the bias voltages will be available after the flight The first step is to order the current values to the corresponding bias voltage values thus creating the current voltage characteristic curves Icong Ubias t In order to determine the altitude dependence and increase the precision of the measurement the real flight profile shall be obtained from EuroLaunch The measurement error caused by the offset voltage of the precision amplifier is also corrected The results are several mobility spectrums with altitude parameters lcona Upias h The type of ions can be determined on the basis of the breakpoints in the volt ampere characteristic therefore the collected ionized molecules are identified by calculating the gradient of the curves At a breakpoint the bias voltage determines the critical mobility of a specific ion The relation between the critical mobility and the bias voltage is defined as follows b a v NY He WL Uc is the critical mobility ais the radius of the inner electrode bis the radius of the outer electrode Lis the length of the condenser uis the air speed Vis the bias voltage Replacing V with a bias voltage a
61. condenser measurements Obj 5 technical Developing and testing a universal data primary acquisition unit for in situ measurements in the atmosphere and in space 1 3 Experiment Overview The Gekko experiment will perform bipolar air conductivity measurements with a use of Gerdien condensers Obj 2 scientific Determining the altitude dependence of the secondary ion composition of the middle atmosphere up to 80 km TBD The experiment consists of the following elements see figure 2 e wo Gerdien condensers e Electronics box containing the analogue the digital and the PSU boards e Ground Station RX14 GEKKO SEDv5 0 9aug13 Page 15 EUROLAUNCH A DLR and SSC cooperation Figure 6 Experiment overview The condensers are mounted on the outer structure of the rocket and connected to the electronic box with triaxial cables The analogue interface card adjusts the bias voltage of the condensers and measures their currents The overall measurement control the on board data storage and the communication interface is implemented on the OBDH board The experiment is powered by the REXUS Service Module and the power supply is built up on the Power Supply Unit PSU board The ground station receives and displays the measured data RX14 GEKKO SEDv5 0 9aug13 1 4 Team Details 1 4 1 Contact Point Page 16 EuROLAUNCH Budapest University of Technology and Economics Space Research Group
62. critical point of the improvements is the cable assembly of the Gerdien condenser In order to connect the central electrode which is attached to the cable by screw connection a mounting hole shall be left on the outer electrode The increased air pressure in the pipe can cause airflow through this mounting hole thus damaging the insulation of the triaxial cable that actually happened to the Gekko experiment In order to prevent the hot air flowing into the module the hole shall be sealed with a proper material And lastly the soldering connection of the outer electrode shall be replaced by screw connection The short circuit can be prevented without rebuilding the electronics box by placing a capton tape under the PSU board However it is more preferable to change the orientation of the electronics box In this case the static acceleration has much less effect on the panels The failure of the experiment also revealed a possible are of improvement of the REXUS Service Module The REXUS power protection and distribution unit did not limit the input current or the limitation not started before the Gekko experiment was switched off when the short circuit occurred and the experiment remained in off state without trying to power it on again With a small improvement of the service module configurable current limiting switches and a retry algorithm a temporary failure such as the short circuit experienced in the case of Gekko d
63. ct like wings Parachute lines entangle with the condensers Very low current levels not detectable due to internal or external noise sources The timing of bias voltage generation corrupted due to loss of synchronization of the internal RX14 GEKKO SEDv5 0 9aug13 Page 30 EuROLAUNCH A DLR and SSC coop Active cooperation between the Gekko team Eurolaunch and ESA in the mechanical design process Risk has been mitigated to acceptable level No further action is required Risk has been mitigated after cooperation with DLR experts Shake test is required to reduce the risk probability Vibration tests were performed to mitigate the risk to an acceptable level Use of protective covering on the edges of the condensers Clear description of safe handling in chapter 6 Discussed with DLR experts design considered safe from this aspect Discussed with DLR experts design considered safe from this aspect Performance optimization of the analog circuits and proper noise reduction Redundant synchronization signal LO SOE Page 31 EuROLAUNCH A DLR and SSC coop reduces probability increased sampling rate reduces severity Acceptable risk no action Acceptable risk no action MS50 One or both of the condensers Risk has been breaks off of the structure of the mitigated after rocket cooperation with DLR experts Shake t
64. densers can be biased individually The bias amplifiers are built up on the analogue electronic board and described in section 4 5 2 The bias voltage range can be extended by the Bias 60x 1 and Bias 60x 2 control signals see figure 26 RX14 GEKKO SEDv5 0 9aug13 Page 55 EUROLAUNCH A DLR and SSC cooperation 74HC4051 aN x x eio D CIE rl Led ala Micro Controller PIC18F26K22 74HC4051 Flash memory SST25VF080b Figure 26 Gekko digital electronics All of the measured data and bias voltage values as well shall be stored in a non volatile memory Considering a 600s flight time a 16 Mbit flash memory is suitable While the AD and DA converters communicate on the same SPI bus the Flash memory uses a different SPI bus In order to increase resistance against the vibration the internal calibrated RC oscillator is used as clock source instead of external quartz crystal The LO and SOE control signal is used for triggering the measurement These interface circuits are realized on the analogue electronics board The schematic of the OBDH board is shown on the next figures RX14 GEKKO SEDv5 0 9aug13 Page 56 EUROLAUNCH A DLR and SSC cooperation ho DVDD A C1 C ADC STARP ADC STAR 10 SOV 100n 50v AD CHSO 2 DGND DGND ERI AD CHS2 AD OHSS AD CHSA ER SPH SDO AD CHS5 NE SP SDI Ir Mes PCO a EZ RX tte R5422 T C4 13 15p 50V E
65. e 11 Thermal test PSU Test type Thermal Test facility Thermal chamber at BUTE Tested item PSU breadboard Test level procedure Board level Acceptance test 4hrs and duration Test campaign duration 1day Verified Requirements P8 P13 D2 D14 D15 The test objectives After the breadboard production the dc and ac parameters RX14 GEKKO SEDv5 0 9aug13 Page 2 EuROLAUNCH are measured The test aims to make the final adjustments on the PSU and verify the related performance and design requirements Both static and dynamic measurements are performed at 3 different temperature level 40 25 and 70 degrees Under the static measurements values of the voltages and the currents are recorded Under the dynamic measurements the switch on current and voltage signals are recorded Table 12 Thermal test Analogue electronics Test type Thermal Test facility Thermal chamber at BUTE Tested item Analogue electronics breadboard Test level procedure Board level Acceptance test 4hrs and duration Verified Requirements P5 P7 D2 The test objectives After the breadboard production the dc and ac parameters are measured The test aims to make the final adjustments on the analogue electronics verify the related performance and design requirements and to produce the scale factors according to the temperature Both static and dynamic measurements are performed at 3 different temperature level 40 25 and 470 degre
66. e molecules Before the presentation of the measuring method a few property of the ions shall be described These are the mobility mean free path and collisional cross section Mobility is the capability of movement of an ion in an electric field So it shows how much the field can accelerate the particle It is defined by equation 1 1 1 and its dimension is m Vs SE 1 1 1 i E To determine the current which is measured during the flight mobilities of the previously mentioned ion groups shall be determined For this purpose the Einstein equation and the ideal gas equation are used as shown D kT 1 1 2 Au Q where D is the diffusion coefficient D LA 1 1 3 free mean path v average diffusion speed he mean free path is the path that an ion can do without collision with another particle It is get 1 1 4 Os collisional cross section n average ion density The collisional cross section is the area which particles cannot pass without a collision with another particle If we assume that ions are like spheres we get the following expression from the differential cross sections formula d 1 1 5 RX14 GEKKO SEDv5 0 9aug13 Page 9 EuROLAUNCH d diameter of the molecule The density is expressed by the ideal gas equation pV NKI E 1 1 6 V XT Thus for the mean free path we get the following expression AKT pda 1 1 7 Equation 1 1 7 shows that if the pressure is
67. e saturation current of the ion groups so we get a full scale of ions with different mobilities I Iaari lsat Tau tz U Figure 4 Characteristic curve in case of several ions presence This is the method by means of which we can distinguish the different ion groups in the middle atmosphere The ion densities can be determined from the saturation currents and then the mobilities of the different ion groups can be found as it is shown below I gt Hu Aq nvAQ 1 3 2 m uy ee 1 3 3 i i Eo RX14 GEKKO SEDv5 0 9aug13 Page 13 EUuROLAUNCH 1 3 4 For the different saturation currents we have the expressions L I La V LSAT UE I l Ly sar dl a V s L L 1 3 5 V ev on 7 A volt ampere characteristic of a multicomponent ion gas is shown in figure 5 This curve is not linear so we have to use the last expression above Ly sar d dl dl Lop V SE ASAT n dV dV U Figure 5 volt ampere characteristic multicomponent ion gas RX14 GEKKO SEDv5 0 9aug13 Page 14 EuROLAUNCH 1 2 Experiment Objectives Obj 1 scientific Recording ion mobility spectrum of positive primary and negative ions in the middle atmosphere Obj 3 scientific Determining the bipolar air conductivity of secondary the middle atmosphere up to maximum 80 km TBD Obj 4 technical Developing and testing a rocket borne primary platform for Gerdien
68. e service module see chapter 6 1 3 and the operational time is 10min The power consumption doesn t changes significantly while the experiment is powered RX14 GEKKO SEDv5 0 9aug13 Page 60 EUuROLAUNCH Table 8 Detailed power budget Maximum Power Energy power consumption consumption consumption with 20 margin PSU board 300mW 360mW 60mAh Analogue board 350mW 420mW 7OmAh OBDH board 150mW 180mW 30mAh 800mW 960mW 160mAh 4 8 Software Design After the experiment is powered on the system initialization is executed and the system steps into standby mode In this mode the HK data collection is performed in every 5 seconds The HK data frames are stored in the onboard flash memory and transmitted to the GSE as well At this stage the software accepts telecommands such as download flash memory content erase memory or test run The system changes into prepare mode and sends LO detected string to the ground station when the LO signal is pulled down In this mode no current measurement is performed The nominal operation mode is triggered by the SOE control signal The bias voltage sweeps and measurements starts after SOE trigger event and synchronized to the internal timer All of the measured data is stored into the flash memory and transmitted to the ground station as well The measurements can be triggered by TC during tests After all of the measurements are done the software steps into post operational
69. enser 8 Investigations are especially interesting at high latitudes where galactic cosmic rays participate in greater degree in ionization processes This means RX14 GEKKO SEDv5 0 9aug13 Page 7 EuROLAUNCH that not only particles of greater penetrating depth considering the lower ionosphere but also greater fluxes due to the decrease of magnetic rigidity should be considered The polar cap where measurements will be carried out is also a special location from the point of view of ionization taking into account the direct connection partly to the tail of the magnetosphere partly to the interplanetary space Therefore it is suitable to monitor from time to time the state of the atmosphere at greater altitudes and at high latitudes as well We are going to use Gerdien condensers to perform our measurements The condensers are going to be placed on the outer side of the rocket and as it moves air flows inside the outer electrodes The ion flow is directed toward the central electrode of the Gerdien condensers due to the electric field between the inner and outer electrodes At a given speed the applied bias voltage determines the minimal mobility that an ion has to have in order to reach the central electrode Since the critical mobility varies on the electric field of the condensers the group of the captured ions can be selected by changing the bias voltage During the flight several voltage sweep will be performed The ran
70. ent gone through is bent RX14 GEKKO SEDv5 0 9aug13 Page 133 EuROLAUNCH e e Figure 59 The highlighted pins touched the module After this inspection we were able to find the most probable cause of failure of the voltage reference Figure 60 shows a model to understand where did the high current flow and how did the potential of the structure shift The high current induced by the short circuit of the 28V line flowed through the structure causing a dU voltage drop on its impedance Since the 28GND line was not shorted its potential remained OV As shown on figure 60 the dU potential appeared on the voltage reference IC increasing its current and damaging the IC RX14 GEKKO SEDv5 0 9aug13 Page 134 EUROLAUNCH High Current High Current Si Voltage drop NE 28V 28V Power line impedance shorted potential dU 428V BUS shorted LM285 1 2 No voltage drop 28V GND 28V GND line impedance Structure Structure impedance im High Current Figure 60 Modelling the effect of the short circuit The failure analysis regarding the electronics came to a conclusion The short circuit was the consequence of the bend of the PSU board due to the high acceleration after lift off On the PSU board 7 pins were found that probably touched the structure Since the short circuit current was high enough to induce a voltage shift on the structure resistance
71. ent the parachute lines from entangling The condensers are placed at the 90 and 270 positions the O position is highlighted on Figure 6 by a vertical line on the module wall RX14 GEKKO SEDv5 0 9aug13 Page 35 EUROLAUNCH A DLR and SSC cooperation mp Figure 11 a Fixing points of the condensers Figure 11 b Mounting the condensers RX14 GEKKO SEDv5 0 9aug13 Page 36 EUROLAUNCH Fixation and mounting of the electrical box The electrical box will be fixed by bolted connections to the bulkhead of the experiment unit Figure 12 a shows the structure of the electronics box while figure 12 b shows the fixation of the electronics box to the bulkhead The PCBs in the electrical box will be fixed by card lock retainers see Figure 12 a We will use nord lock washers for all bolted connections and thread fixer glue If needed At the bottom of the electronics box we need a flat surface that fits to the bulkhead therefore we use countersunk head bolts that is the only part where the nord lock washers can t be used see Figure 1 a Helicoils will be inserted into the wall mounted bulkhead thus we can mount or dismount the electronics box multiple times without damaging the threads BERE IT K ween tu Ab Figure 12 a Mounting the electronics box Figure 12 b Mounting the electronics box RX14 GEKKO SEDv5 0 9aug13 Page 37 EUuROLAUNCH List of fasteners Gerdien condensers e 2 pieces
72. er method It is obvious from figure 2 that there is a time limit for an io to move from the outer to the inner electrode If the time that an ion needs to travel through the condenser without hiting the inner electrode is greater than the time that is needed to reach the end of the condenser then no current can be measured An ion with mobility u moves an incremental distance in the electric field E y dr vdt e uEdt 1 2 1 oolving this differential equation we get the total time that an ion needs to move from the outer electrode to the inner electrode 1 a f rar 1 2 2 AV If we assume that the rocket air is moving with a speed u then the distance that an ion travels is u t If that length is less than the length of the condenser L ut lt L then all ions are collected and we get an inequality 2uVL b wmd a ut lt Lou lt 1 2 3 Now the critical mobility can be defined Equation 1 2 4 shows that the critical mobility is inversely proportional to the bias voltage thus the applied voltage can be expressed from this equation RX14 GEKKO SEDv5 0 9aug13 Page 11 EuROLAUNCH 2 2 b b a wi 1 25 2 UL In ideal case ions move along a parabolic path but in reality they can enter into the condenser with different angles and thus few can be collected with mobilities slightly less than the critical mobility As the bias voltage is determined the current can be estimated From Gau
73. erification methods Follow the guidelines outlined in the verification presentation o Your Test Plan will require further elaboration specifying all tests functional performance mechanical etc and which facilities you will need You should also begin considering any special requirements and consumables which may be required for certain tests Safety and risk analysis o The technical risks outlined in the SED were very well considered RX14 GEKKO SEDv5 0 9aug13 Page 145 EuROLAUNCH However it is recommended that you also incorporate project planning risks into your risk register including loss of personnel through illness injury or withdrawal Manufacturing and integration risks should also be included such as damage to critical components late delivery of materials etc Please give as much thought as possible to all risks Launch and operations SED chapter 6 o The physical properties of the experiment were completed to a high standard but the rest of Chapter 6 will require elaboration prior to submission of SED v2 0 o Chapter 7 will also require further elaboration At this stage you should have a good idea of how you will analyse your data after recovery this should be presented accordingly Organisation project planning amp outreach SED chapters 3 1 3 2 amp 3 3 o The WBS was well thought out and well defined as was the Project Schedule The panel commends you for this o It is strongly recomme
74. es In case of the amplifiers the offset and offset drift are measured Table 13 Thermal test OBDH Test facility Thermal chamber at BUTE Tested item OBDH breadboard Test level procedure Board level Acceptance test 4hrs and duration RX14 GEKKO SEDv5 0 9aug13 Page 73 EUuROLAUNCH Verified Requirements D2 D10 D11 The test objectives This test is to verify that the OBDH electronics are able to operate in the REXUS thermal environment Both static and dynamic measurements are performed at 3 different temperature level 40 25 and 0 degrees Table 14 Software test OBDH GSE Test number 5 Test type Electrical Test Test facility otudent laboratory of the University Space Research Group Tested item OBDH breadboard Test level procedure Board level Acceptance test 4hrs and duration Test campaign duration 2days Verified Requirements F6 F7 O1 O5 The test objectives This test is to verify that the software of the EGSE and the software of the OBDH are working properly Table 15 Thermal test Test number Test type Thermal Test facility Thermal chamber at BUTE Tested item Breadboard model Test level procedure System level Acceptance test 4hrs and duration Verified Requirement F2 F3 F5 F7 D2 D10 D12 O1 O4 O7 The test objectives This test is to verify that the experiment is working properly Both static and dynamic measurements are performed at 3 different tempe
75. est is required to reduce the risk probability MS51 Residual of MS50 Vibration tests were performed to mitigate the risk to an acceptable level PE10 Loss of personnel No action required backup persons are available both physicist and engineer PE20 No backup person for mechanical Risk is on acceptable design level Searching for backup person is in progress Procurement of spare parts TC20 Late delivery of components or Ordering materials during development components and materials with duly considered time reserve TC30 Late delivery of experiment Dispatch of hardware hardware for integration with duly considered time reserve RX14 GEKKO SEDv5 0 9aug13 Page 32 EUuROLAUNCH 4 EXPERIMENT DESCRIPTION 4 1 Experiment Setup The Gekko experiment consists of two Gerdien condensers and an electronic box The condensers are mounted onto the outer structure of the rocket and the electronic box Is placed inside the module The electronic box contains four PCBs the PSU board the OBDH board the PCB for the analogue electronics and the motherboard See figure 9 The interface connector to the RXSM the technology connector and the TNC connectors to the condensers are placed on the electronic box The condensers are connected to the electronic box by triaxial cables The signal and power connections between the 3 PCBs analogue electronics OBDH PSU and the external IF connectors are imple
76. et to its O 5 initial value after pre flight tests by a ground command The content of the onboard memory shall be downloaded to the ground station after payload recovery The ground station shall store the received data onto a hard drive during the flight RX14 GEKKO SEDv5 0 9aug13 Page 23 EUROLAUNCH A DLR and SSC cooperation 3 PROJECT PLANNING 3 1 Work Breakdown Structure WBS Figure 7 Gekko Team WBS RX14 GEKKO SEDv5 0 9aug13 WP1 Task 1 1 PSU Task 1 2 OBDH Task 1 3 An electronics Task 1 4 Task 1 5 WP2 Task 2 1 Mech Dimensions Task 2 2 Task 2 3 Task 2 4 Task 2 5 Task 2 6 Task 2 7 WP3 Task 3 1 OBDH SW implementation Task 3 2 Ground SW implementation WP4 Task 4 1 Task 4 2 Task 4 3 Task 4 4 Task 4 5 Task 4 6 Task 4 7 WPS Task 5 1 Task 5 2 Task 5 3 Website Task 5 4 WP6 Task 6 1 Task 6 2 Task 6 3 S PDR CDR IPR i di D EAR UROLAUNC A DLR and SSC cooperation Camp ENT OLIPFIMLALM PSPS TALSPLOIN DP JTF IMLALTM S breadboard Task 1 1 1 Futo i flight Task 1 1 2 P breadboard Task 1 2 1 Gugyin flight Task 1 2 2 breadboard Task 1 3 1 Kollek Varadi B flight Task 1 3 2 Futo Gugyin Integration Kollek Test electronic box Task 2 1 1 uda gerdien cond Task 2 1 2 L rinczi verify Task 2 1 3 Material selection Mechanical IF design Electronic box mounting Lorinczi Condenser placement Modal analysis Airflow analysis Flo
77. f femodule ccc cccccecccececeeeseeeeeeeeeeeeees 117 6 2 2 HV system description safe handling 118 6 3 Timeline for countdown and Tlht ccc cccc cece ccc eeeeeeaeeneeenes 119 6 4 JPOSEFPIIGnE er 120 PDATAANALY EN M 121 7 1 Data Analysis Plan usus Ue P Du SU Pip Dudas Dub Db Du ix 121 ke Eeer ee 123 7 2 1 Flight preparation activities 2 123 ez IEN 123 ac Sce 134 7 3 1 Technical and scientific results 134 7 3 2 Outlook improvements and recommendations 134 1 4 Lessons Lealtied WEE 135 ABBREVIATIONS AND HREFERENCEGS cecneeceeeneeeeeeneenes 137 E NEE ele Le DEET 137 8 2 I II ARIETE Age 139 Appendix A Experiment Reviews nnne 141 Appendix B Outreach and Media Coverage sonennsrernsrrererrererrrrerrererrerrn 159 Appendix C Additional Technical Information s s 160 RX14 GEKKO SEDv5 0 9aug13 Page 5 EuROLAUNCH ABSTRACT Our scientific objective is to study the ionization of the atmosphere in different altitudes We want to measure the variations of electric conductivity with altitude by recording the mobility spectrum of positive and negative ions The measurements will be carried out by using Gerdien Condensers ouch investigations are especially interesting at high
78. f the undisturbed flow velocity u 0 99 u 1 The thickness depends on the type of the flow assuming laminar flow the boundary layer is thinner than in turbulent flow The flow type laminar or turbulent is highly dependent on the density compression properties of the air and on the flow velocity Due to the high flow velocity it is recommended to assume turbulent flow in the boundary layer this of course does not mean that the flow is also turbulent outside the boundary layer Based on the properties of the air valid near the surface a worst case value can be obtained if the results of the worst case calculations are appropriate so they will be for all other case An RX14 GEKKO SEDv5 0 9aug13 Page 94 EuROLAUNCH additional safety factor of n 2 can be used to determine the condenser distance with absolute certainty 1 Assuming laminar flow d x z 491 Vex 4 91 x uy Re 2 2 Assuming turbulent flow 0 382 x d x Re 3 where the distance from the entry edge in x direction m X X specific length m y the distance from the wall in y direction m d thickness of boundary layer m Re Reynolds number Un velocity of undisturbed flow m s 1250 m s u y flow velocity m s u dynamic viscosity Pa s v kinematic viscosity m s p density kg m Reynolds number on A uX H yv 4 Re RX14 GEKKO SEDv5 0 9aug13 Page 95 EuROLAUNCH
79. ge of each bias voltage sweep is calculated taking into consideration the velocity of the rocket The ion density is determined by measuring the current of the condensers 11 To do correct measurements some crucial requirements shall be defined previously such as the applied bias voltage range in different altitudes or the saturation current These requirements determine parameters of the electronics On the next few pages we try to give a clear description what are these requirements and how we fulfil those The molecules which exist in the middle atmosphere consist mainly of oxygen nitrogen hydrogen and hydrates Due to ionization effects e g collisions photoelectric effect Lenard effect electrons are released from molecules thus positively charged ions will be produced These electrons are attached to neutral molecules e g oxygen nitrogen creating negatively charged ions and combined with water molecules A few ions we used in our calculations are shown below e the photoionisation of direct and scattered Lyman radiation NO e the photoionisation by galactic cosmic rays O 02 N Na e the dissociative electron attachment to O4 and three body attachment to O O 07 RX14 GEKKO SEDv5 0 9aug13 Page 8 EuROLAUNCH e the positive secondary ions and ion clusters 027 X NOS X halogen e the negative secondary ions 03 CO3 NO7 OH NO CO Oy HCO3 In the middle atmosphere molecular weight does not separat
80. gn o Review and address all discrepancy items and inconsistencies listed within this report prior to submission of SED v2 0 PDR Result pass conditional pass not passed o Pass u Next SED version due o SED v2 0 RX14 GEKKO SEDv5 0 9aug13 Page 147 EUROLAUNCH A DLR and SSC cooperation Experiment Critical Design Review Flight REXUS 14 Payload Manager Mikael Inga Experiment GEKKO Location DLR Oberpfaffenhofen Germany Date 04 07 2012 1 Review Board members Mark Fittock DLR Bremen Martin Siegl DLR Bremen Andreas Stamminger DLR MORABA Tobias Ruhe DLR MORABA Nils Hoeger DLR MORABA Frank Hassenplug DLR MORABA Markus Pinzer DLR MORABA Frank Scheuerpflug DLR MORABA Alexander Kallenbach DLR MORABA Wolfgang Jung DLR MORABA Natacha Callens Esa Education Alex Kinnaird Esa Education minutes Koen DeBeule ESA Technical Directorate Mikael Inga SSC Solna chair Jianning Li SSC Solna 2 Experiment Team members G bor Balassa BUTE Ott L rinczi BUTE Zsolt V radi BUTE B lint Kollek BUTE 3 General Comments Presentation o The presentation was good Speakers were confident and engaged the audience a SED o There is a marked improvement in the document from PDR well done o However there are still minor points which need improvement e Chapter 7 needs expanding and clarifying RX14 GEKKO SEDv5 0 9aug13 Page 148 ee qu NW 4 EUROLAUNCH A DLR and SSC c
81. he value of 41 2 MPa is less than the 10 of the acceptable stress for the used material it poses no risk RX14 GEKKO SEDv5 0 9aug13 Page 85 EuROLAUNCH The test results for the z axis peak acceleration is 130 me Table 28 Analysis results z axis The maximal stress of 4 36 MPa occurring at the base of the additional struts is negligible considering that the yield point of the stainless steels is above the aforementioned value by two orders of magnitude Table 29 Analysis results inner electrode x axis Max Deform 4 76 10 Max Strain 4 41 10 RX14 GEKKO SEDv5 0 9aug13 Page 86 EuROLAUNCH ANDIKO Wail B 42s SE ad 2133e i SEET e E m gar e kee iii US N p Ze B aa te e 190567 4 m 106367 5 55ef 4 364e6 Max 3 208e6 2 036e6 212465 0 090 m Y NENNEN WE Figure 41 Maximal stress response inner electrode z axis 0 4564 Min The maximal stress of 38 4 MPa must be taken into account however the yield point of the inner electrode is over 100 MPa In conclusion the welds are the critical parts of the construction but the stress is rather low a safety factor of 2 can be applied for all parts for the struts even a value of 10 It is important to emphasize that the inspection of the weld quality is essential defects and bubbles can weaken the weldment The maximal deformation is below 0 3 mm the effect of deformation on t
82. he ESA REXUS rocket programme Publication at the Urvilag Hungarian web portal http www urvilag hu hazai kutatohelyek es uripar 20120406 magyar kiserlet az esa rex us raketaprogramjaban e L rinczi Ott Botond Gubicza gnes V radi Zsolt Mechanical design of a gerdien condenser for rocket experiment 20th International Conference on Mechanical Engineering Kolozsv r Romania 2012 04 19 2012 04 22 RX14 GEKKO SEDv5 0 9aug13 Page 160 EUuROLAUNCH APPENDIX C ADDITIONAL TECHNICAL INFORMATION Mechanical drawings 228 M25x0 8 Figure C1 Screw cap 4 eS Figure C2 inner electrode RX14 GEKKO SEDv5 0 9aug13 NE zi c me mam mam mm m a T T RR T E T T RD D E E RE T E RE RE RE E E T M S RE E D m A A T NEE KS e EE Figure C5 Gerdien Condenser Assembly RX14 GEKKO SEDv5 0 9aug13 Page 161 EE eg TE p ON P d fine dE P P y A E UROLAUNCH A DLR and SSC c V WK Figure C6 Gekko Experiment RX14 GEKKO SEDv5 0 9aug13 Page 162 e EUuROLAUNCH A DLR and SSC cooper AN Page 163 9 N d d P EUROLAUNCH A DLR and SSC cooperation Designed by Checked by Approved by Date Date Lorinczi Otto Botond Dr Banfalvi A 2012 08 03 Gekko electronics box Edition Sheet EMEN d eg Figure C7 Electronics box assembly RX14 GEKKO SEDv5 0 9aug13 Page 164 EUuROLAUNCH V 126 V L
83. he measurement is not significant The final verification of the condensers will be carried out by vibration test The vibration analysis of the electrical box and parts will be feasible after the finalization of the PCBs After the CDR some modifications have been carried out on the mechanical design of the condensers in close cooperation with DLR MoRaBa Additional struts have been attached to the condensers thus the natural frequencies RX14 GEKKO SEDv5 0 9aug13 Page 87 E UROLAUNCH increased and the stress decreased It can be said that the current and final model have the strongest structure compared to all previous ones The shaker tests test 8 and test 9 were performed in two stages x and y axis in Budapest at EL TECH Center figure 42 and z axis in Bremen at DLR figure 43 Both shaker tests were successful m Figure 42 Shaker test x and y axis RX14 GEKKO SEDv5 0 9aug13 Page 88 EUROLAUNCH A DLR and SSC cooperation Figure 43 b Control station at shaker test Z axis RX14 GEKKO SEDv5 0 9aug13 Page 89 EUuROLAUNCH 5 3 2 Thermal simulation of the condensers The goal of thermal simulation was to determine the cooling ability of the condenser spacers Since the condensers take high amount of friction heat the spacers have a key role in the cooling process The boundary conditions were as follows The heat flux on the condenser is 7000 W m and the temperature of the
84. ht The shift caused by the roll of the rocket shall A D 21 not disturb the measurement The experiment shall be able to conduct 1 measurements autonomously in case connection with the ground segment is lost Done The bias voltage values shall be calculated A 2 according to the predicted flight profile before Done the flight The calculated bias voltage values shall be T 3 uploaded into the onboard non volatile Done memory before the flight OA The start of the measurement shall be T triggered by the LO control signal RX14 GEKKO SEDv5 0 9aug13 elele Done AJ j Page 1 EUuROLAUNCH The onboard memory pointer shall be set to its T O 5 initial value after pre flight tests by a ground Done command The content of the onboard memory shall be T Note Done downloaded to the ground station after payload recovery 0 7 The ground station shall store the received T Done data onto a hard drive during the flight 5 2 Test Plan Table 10 Electrical test Electrical Performance Test Student laboratory of the University Space Research Group Tested item Breadboard circuit precision amplifier Test level procedure Unit level Performance test and duration Verified Requirements P6 P7 The test objectives The test aims to determine the maximum sensitivity of the percision amplifier This test is to verify the calculations by using the reference test generator Tabl
85. i YOL VS dgg Ex 82 9 09X1Svig ASLHELNV gni 612 gt gt Z gt z zZ x 2 0 SVIB eo E z 3 08 SvIg Ld Figure 24 Amplifier schematic g13 RX14 GEKKO SEDv5 O 9au Page 54 EuROLAUNCH Figure 25 Control IF circuits 4 5 3 Digital electronics The digital electronics of the Gekko experiment are located on the OBDH board The OBDH board is consists of a PIC18F microcontroller a flash memory chip the RS422 I F IC an AD and a DA converter see figure 26 The OBDH board is connected to the motherboard by a 96pin B2200 R960 type connector The 16 analogue channels including the outputs of the amplifiers the applied bias voltages and the TM lines are connected to the ADC by two multiplexers The ADC is a 16bit precision AX converter with a built in voltage reference The communication between the ADC and the microcontroller is performed on the SPI bus A symmetrical 2 5V analogue supply voltage is applied to extend the analogue input voltage range to 2 048V to 2 048V In that case the ADC runs on 15 bits resolution which means 0 0625mV LSB During a sweep the condenser current and bias voltages also need to be measured in every single point To record a 64 point mobility spectrum in a second P 3 256 AD conversion is needed for each condenser so the sample rate of the ADS is set to 1000 s The DAC has two independent analogue output so the Gerdien con
86. ight Simulation Test Flight Requirement Plan Flight Readiness Review Ground Support Equipment House Keeping High Voltage Hardware Interface Control Document Interface Interim Progress Review Lift Off Local Time Line of sight RX14 GEKKO SEDv5 0 9aug13 Mbps MFH MORABA OP OBDH PCB PDR PST PSU SED oNSB SODS SOE SSC STW S W TBC TBD UVLO WBS Page 138 EuROLAUNCH Mega Bits per second Mission Flight Handbook Mobile Raketen Basis DLR EuroLaunch Oberpfaffenhofen DLR Center On Board Data Handling Printed Circuit Board electronic card Preliminary Design Review Payload System Test Power Supply Unit otudent Experiment Documentation owedish National Space Board otart Of Data Storage otart Of Experiment owedish Space Corporation EuroLaunch otudent Training Week ooftware Time before and after launch noted with or To be confirmed To be determined Under Voltage Lockout Work Breakdown Structure RX14 GEKKO SEDv5 0 9aug13 8 2 1 2 3 4 5 6 8 9 10 11 12 Page 139 EUuROLAUNCH References Books Paper Proceedings EuroLaunch BEXUS User Manual 2010 REXUS User Manual 2010 European Cooperation for Space Standardization ECSS Space Project Management Project Planning and Implementation ECSS M ST 10C Rev 1 6 March 2009 SSC Esrange Esrange Safety Manual EU A00 E538 20 March 2006 European Coope
87. ight be needed to calibrate condensers bias voltage set to wide range Requirements and constraints SED chapter 2 e Nocomments Mechanics SED chapter 4 2 1 amp 4 4 e Design is frozen after discussion with DLR MORABA e 6weeks to manufactory get go ahead from EuroLaunch e 2 3 weeks to manufactory the OBDH box e Condensers and module to be vibration tested at 12g qualification levels e Electronics to be vibration tested at 6g acceptance levels e Manufactory by team or get a bulkhead e Delivery of module from EuroLaunch Electronics and data management SED chapter 4 2 2 4 2 3 4 5 amp 4 7 e Reuse of design from Biodos e Power supply High Voltage switching problems probably already solved RX14 GEKKO SEDv5 0 9aug13 Page 153 EUROLAUNCH A DLR and SSC cooperation P D a REXUS Experiment Integration Progress Review EUuROLAUNCH Page 3 e Amplifier board is new but design is almost finished tested on breadboard e Already breadboard testing of all subsystems e All components in house Thermal SED chapter 4 2 4 amp 4 6 e Condenser measurements not sensitive to melting material Software SED chapter 4 8 e LO and SOE signals can be tested e Only one parity bit is used for downlink checksum Verification and testing SED chapter 5 e Thermal and Vacuum tests on system level some breadboards already tested still to be done e Vibrating test outer parts qualification leve
88. is very low the lift created by the struts cannot endanger the mission RX14 GEKKO SEDv5 0 9aug13 Page 99 O EUuROLAUNCH 5 3 4 Calculations on the effect of roll during flight Verification of D 21 The effect of the 4 Hz roll should be taken into consideration in the range relevant for the measurement more precisely in the lowest speed point of the above mentioned range If the velocity conditions are appropriate in the critical point there is no need of further investigation but when the results predict possible occurrence of problems the range suitable for the measurement should be determined Altitude LI c Jn am c Im c Altitude m Le _ E X E T 2 2600 c J E o sl lu c nd c LL LA a 100 Time s Roll Rate cC kel S Roll Rate degs s Figure 50 Velocity Altitude and Roll characteristics of the rocket 12 RX14 GEKKO SEDv5 0 9aug13 Page 100 EuROLAUNCH The measurement will be carried out in the 25 90 km altitude range the velocity in this range is between 250 1250 m s the roll frequency varies between 0 4 Hz That is the following data is valid in the planned range of the measurement Roll frequency 4 Hz Minimum velocity 250 m s The larger inner diameter of the condenser is 22 mm the symmetry axis of the condenser is approximately 200 mm from the center line of
89. is the very low input bias current Taking into account the above mentioned parameters the OPA124 is a suitable operation amplifier Even so the chosen operation amplifier has very good performance the input bias current is close to the current which has to be measured So the compensation circuit has to deal with this current flow too Fortunately the noise and the drift voltage of the amplifier are much lower than the output voltage we do not have to care of them To perform the bias voltage adjustment two analogue signals are received DA1 DA2 and amplified into the required range Since the bias voltage shall be adjusted between 10mV and 50V the 12bit DA converter is unable to cover the required voltage range with a single stage amplifier In order to extend the voltage range the bias voltage amplifiers are able to operate in 1x and 30x amplification mode RX14 GEKKO SEDv5 0 9aug13 Page 52 EUuROLAUNCH The bias voltage adjustment and current measurement needs isolated power supply for the precision amplifiers 15V The GND 1 GND 2 are connected to the inner electrode of the condensers The schematic of the circuit is shown on figure 24 RX14 GEKKO SEDv5 0 9aug13 Page 53 A DLR and SSC cooperation EUROLAUNCH gt a lt SS di Eat SC Az SELENI E d a Ke S x00 100 veer or 2991 AGA NY 912 ZO pos gt n zivdO DS en ZONO oot gt 62 2 z zayp z Ka Gesi lt pa
90. ith your current material choice it is likely it s insufficient you should review this and consider another material perhaps steel chapter 4 8 You should clarify who in your team is responsible for software and possible get some help if you need it Consider carefully your choice of microprocessor Consider sending all raw data rather than using compression it won t cost that much more and may be more reliable Include the logging of your received data in your SED Verification and testing SED chapter 5 O O O In general you need expand your test plan You should include an RF test For your aerodynamic test ensure you have all the boundary conditions put these in the SED A coronal test should be included as you use 100V in a reduced pressure environment Y our vibration levels should be at qualification not acceptance It is recommended you perform a shaker test at qualification level for the Gerdien condensors Safety and risk analysis SED chapter 3 4 O OO o You should include the risk of one or both of the condensers breaking off both to the experiment and the rocket Update risk register to include all failure mechanisms for example the above comment consider risks to the rocket from your experiment For personnel risks consider that you have no back up for your team member responsible for mechanical It doesn t seem like FS10 and MS10 have been mitigated make sure they a
91. l be performed 1 between 0 005 and 15 m Vs for positive ions and from 0 01 to 20 m Vs for negative ions D with an accuracy of 0 001 m Vs for both positive and negative ions P P P both positive and negative ions The ion mobility measurements shall be performed 3 at a rate of 128 measurements every second for The bias voltage of the Gerdien condensers shall P 4 be adjusted in the range of 10 mV to 120 V for the positive ions and 10 mV to 120 V for negative ions The bias voltage of the Gerdien condensers shall P 4 be adjusted in the range of 10 mV to 50 V for the positive ions and 10 mV to 50 V for negative ions The bias voltage adjustment of the Gerdien P 5 condensers shall be performed with a minimum accuracy of 10mV The current of the Gerdien condensers shall be measured in the range of 5pA to 2nA D The current measurements of the Gerdien P 7 condensers shall be performed with a minimum accuracy of 1pA The PSU shall provide a 5V 2 5V anda 3 3V output with 10 accuracy pg The PSU shall provide two 15V outputs and a 120V output with 10 accuracy The PSU shall provide two 15V outputs and a 60V output with 10 accuracy The input current measurement shall be possible in the range of 20mA to 200mA 11 The input current measurement shall be performed with an accuracy of 2mA resolution 12 The input voltage measurement shall be possible in
92. locity is 4 65 m s Therefore the condenser clears 2 325 mm distance perpendicular to the travelling direction of the rocket Based on the 2 325 mm shift present in the 25 80 km altitude range it can be said that the shift is approximately 10 of the condenser diameter At higher velocities shift reduces to 0 6 mm namely 2 72 of the condenser diameter Accordingly the roll of the rocket does not effect the measurement in the altitude range of 25 80 km At the lower velocity ranges reducing the effect of roll a possibly used correction factor could increase the reliability of the measurement results RX14 GEKKO SEDv5 0 9aug13 Page 102 EUROLAUNCH A DLR and SSC cooperation 5 3 5 Electronics Board level tests PSU The breadboard model of the PSU was built up and tested on room temperature Table 30 shows the outputs at different input voltages Temperature 25 C Uin V set ee OO Lm T oem max min nom max L 43 600 54 800 min nom in V measured in mV mA 2 5 V 2 400 20 D I aux V T0600 2 5 mA ay 2 5 V o 2 5 mA EH 3 3 V 3 383 3 3 mA 5 V 45 mA 5 V 5 mA 15 1 V 415 1 mA 15 1 v 15 1 mA 15 2 V 415 2 mA 15 2 V 15 2 mA 170 V 4120 mA 120 V 120 mA d X SS p NEE p RENNES L 5 500 6 080 pud p D eg E NENNEN 0235 0 914 0362 0 982 L 2248 3 24
93. ls level electronics acceptance levels e RF tests to determine if transmitters will disturb condenser measurements e Aerodynamic testing Safety and risk analysis SED chapter 3 4 e SF 11 replaces SF 10 SF10 High not acceptable Launch and operations SED chapter 6 e No TC during flight e Power off at end after 400s Organisation project planning amp outreach SED chapters 3 1 3 2 amp 3 3 e EAR in end of November beginning of December e Webpages and etc to be updated SED End to end Test e Not performed Others e No Comments FINAL REMARKS RX14 GEKKO SEDv5 0 9aug13 Page 154 EUROLAUNCH A DLR and SSC cooperation p REXUS L Experiment Integration Progress Review EUROLAUNCH Page 4 Summary of major actions for the experiment team e Finalize and go into testing phase IPR Result pass conditional pass fail e Conditional pass updated SED to be submitted Next SED version due e TBD Alex Kinnard ESA Summary of actions for EuroLaunch e Send module to team e Send bulkhead to team if we have one ASAP e EAR PL Integration Bench test time and Place RX14 GEKKO SEDv5 0 9aug13 Page 155 EUROLAUNCH REXUS e Experiment Acceptance Review EuroLAUNCH Pagel REVIEW Flight RX 14 Experiment Gekko Review location Budapest Date 06Dec2012 Review Panel Dr Alexander Schmidt DLR MORABA Experiment Team members Zsolt Varadi Otto Lorinczi Gabor
94. lugged into the motherboard with 96pin B2200 R960 type connectors 4 3 Experiment Components Table 4 Experiment component list Componentname Jon Note Status Electronic box 1 125 x 165 x 105 826g Gerdien condensers 265 x 25 x 280 306 5g DBiscomesor 1 delvered DB26 connector 1 delvered SMA angle crimp _2 Telegariner delere RX14 GEKKO SEDv5 0 9aug13 Page 41 EUuROLAUNCH SMA straight PCB 2 Teeg tner delivered PsupB a o aeieea C 1 delivered Motherboardpca 1 liebe Sieger 1 delverd mosmas aoc delvered PICIBF2GKZZ alus delveed SsTasvrosob 1 Fashmemory delivered snrancaos 2 Wux delivered mat Ise delivered Mceap apace delveed oparz 2 precision opamp delivered mosa ijopamp eive Lwza Jang deleed Bet 2 wchmoset delivered Bre _6 highvoltagenpn delivered Bras 6 high voltage pnp delverei m efron J mae i cwrenttm delvered eg leen delveed mg avre delivered De lang ise sEsss 1 monostab delivered zwmork 2 pnpw delivered zum Ilan delvered Eros ijfem deed Table 5 Experiment summary table Experiment mass in kg 1 634 condensers 0 817 kg each 0 826 electronic box 2 460 electronics box amp condensers 8 209 total mass with module bulkhead Experiment dimensions in m 0 065 x 0 025 x 0
95. main and redundant e Runthe ground software e 600s experiment is powered connection with the main Ground Station shall established e 590s HK data collection and monitoring the LO signal starts e 300s run a test to check the offset voltages of the amplifiers e T 0 detection of the LO signal is reported to the Ground Station e T 26s data acquisition starts after receiving the SOE signal e T 81s System steps into post operational mode Bias voltage is set to OV and measurement is stopped HK data acquisition remains while external power is available RX14 GEKKO SEDv5 0 9aug13 Page 120 EUuROLAUNCH 6 4 PostFlight Activities e Equipment recovery done by SSC Note After the experiment is powered off the power supply stops and the high voltage discharges in less than 1s e Remove the condensers and the electronic box from the module Ott L rinczi e Loading the content of the on board memory to the Ground station G bor Balassa e Pack up the electronic box and the condensers and transport them back to BUTE Gekko team members e Analysis and evaluation of scientific and HK data G bor Balassa e Publishing results RX14 GEKKO SEDv5 0 9aug13 Page 121 EuROLAUNCH 7 DATA ANALYSIS PLAN 1 1 Data Analysis Plan The Gekko experiment will carry out air conductivity measurements in the altitude range of 22km and 75km While the measurement is running one mobility spectrum is being recorded in every sec
96. mechanical structure of the Gerdien condensers we have to deal with extremely low current flows These low current flows typically nanoampers require a very precise measurement circuit which able to give correct results he conventional high side current monitoring is not good at this case because of the low currents and the external noises Therefore the chosen measurement method is the comparative current monitoring which means that the measuring circuit always response with the same value of the incoming current but the sign of the current is reverse In the feedback path we can measure a voltage level which is proportional with the value of the current Theoretical block diagram of the precision low current measurement circuit RX14 GEKKO SEDv5 0 9aug13 Page 51 EuROLAUNCH Theory of the operation CLEC EPL eee ETTTEEEEETTTTEEEEETE TE ANETTE KETTEN ETT Peer eee eee EE Figure 23 Low current measurement Considering an ideal operation amplifier the integrator s capacitor potential is unchanged if Ic is zero In any other case the value of Ic is equal to lin Icomp Therefore in steady state the incoming current s absolute value is equal to Icomp In the real word if we want a precision circuit and keep the measurement error below 10 percent we had to choose the exact components semiconductors very carefully The key parameters for the operation amplifiers are low offset voltage low drift voltage and the main
97. mented on the motherboard The PSU board provides different power lines including HV outputs 60V for the OBDH and the analogue electronics as well The electrical connections between the outputs of the PSU are shown in figure 10 The power supplies of the precision amplifiers output A1 and A2 are not linked directly to the RXSM 28V these outputs are connected to the 28V Ground on the analogue electronics board with 100kO resistors The other ground points are combined in a star ground which is implemented on the motherboard The power supply voltages and the temperature is monitored and measured as HK data There are several analogue and digital signal lines between the analogue PCB and OBDH as shown in the figure The current of the condensers and the bias voltages are measured by the AD converter on the OBDH board Due to the large scale of the bias voltage the gain of the bias voltage amplifiers shall be switched by the microcontroller The experiment is interfaced with the RXSM and uses the RS422 communication interface the power interface and the LO and SOE control signals RX14 GEKKO SEDv5 0 9aug13 Page 33 A DLR and SSC cooperation EUROLAUNCH o1njonijs og oruoijoe gA4 Azoureu e yseTa TET TOIT4UODOIO TW og 2 o IZ alk SEKR OI ke V A A T XETII OAS aas Oud Ss TU CELL qiexe drarnW EE M IO dq H odnjonijs Ast
98. mm of the rocket wall its inlet will be reached by an undisturbed laminar air flow These caltulations considered that the entry edge is perpendicular to the airflow While the nosecone is on the rocket tip has much better aerodynamic properties as the above mentioned case When the nosecone will be detached the aerodynamics will deteriorate but the distance between the entry edge and the condenser inlet will decrease just as the thickness of the boundary layer near the condensers Based on these assumptions detachment of the nose cone does not affect the experiment except a temporary disturbance at the moment of detachment The risk of the nosecone breaking the condensers down might be considered By this time the condenser placement is fixed The Gekko experiment is placed into the first module under the nosecone The calculations above regarding the boundary layer are valid Note that the wind tunnel test was not done The verification of D17 is based on FEM analysis RX14 GEKKO SEDv5 0 9aug13 Page 97 EuROLAUNCH The study below that was made before CDR closure deals with the relation of the boundary layer and condenser placement It has become clear the placement of the condensers affect the flight stability of the rocket In order to gain stability the condensers may have to be placed at the base of the payload On Figure 49 the distance between the condensers and the rocket wall is determined in order to a
99. nc word and frame counter and proceeds with the data bytes The transmission of the data frame terminates with the time stamp One characteristic curve is recorded in every second and consists of 128 consecutive measurements 64 current and 64 bias voltage values RX14 GEKKO SEDv5 0 9aug13 Page 62 EuROLAUNCH The HK data frame format is similar to the measurement data frames content TM SYNC WORD FRAME COUNT 4 HKDATA TIME STAMP A PL TM PARITY sete 2 gt gt Y Y where HK DATA HK patabyte t2 34 ss 78 910 1112 1344 15 10 e One data frame is 39 bytes long e One telemetry frame is 23 bytes long e All frames contain a unique counter value that can be used as a serial number and also a 22 bit timestamp for further identification e The timestamp started at power on e heresolution of the timestamp is 15 ms e The remaining 2 bits are the HK data indicator and a parity bit for basic error detection As one data frame contains 4 points of the characteristics of both condensers the total 64 points of the voltage ampere curve are transmitted in 16 frames HK data is sent in every 5 seconds The download data rate is calculated as follows 1 datarate E x 23byte x Lobit 16x39bvte 10bit 6240bps The main program flow diagram of the OBDH SW is shown on Fig 31 RX14 GEKKO SEDv5 0 9aug13 Page 63 EUROLAUNCH A DLR and SSC cooperation
100. nded that you recruit more mechanical engineers into your team to support you in the mechanical design and manufacture of the experiment o It is recommended that you recruit a dedicated software student into your team and ensure that he is present at all key events and reviews Most problems stem from under developed software so don t underestimate the amount of time and effort required for development and de bugging o Please re consider your budget At present it seems insufficient to cover the costs of materials equipment testing etc Please provide a detailed break down of the budget including all major costs Others o EuroLaunch can provide predicted trajectory data in advance to aid your bias voltage calculations This can be used either in parallel to or instead of real time data o Please be aware that a separate umbilical for late uploads updates cannot be provided RX14 GEKKO SEDv5 0 9aug13 Page 146 EUuROLAUNCH 5 Internal Panel Discussion Summary of main actions for the experiment team o The main concern for the panel is your mechanical and thermal design The mechanical set up needs to be further defined and analysed taking into consideration all of the points mentioned in the Mechanical section above o The aerodynamic design of your experiment requires further consideration o The allocation of manpower also needs to be addressed More support is required for the mechanical and software desi
101. ng institutes Up to date information will be regularly published both in the News thread of the website and on the facebook page Gekko site http lab 708 mht bme hu gekko Gekko on facebook http www facebook com GekkoTeam Before the CDR the following publications were made about the development of the Gekko experiment RX14 GEKKO SEDv5 0 9aug13 Page 28 EuROLAUNCH Papers Otto Botond L rinczi gnes Gubicza Zsolt V radi Mechanical design of a gerdien condenser for rocket experiment Hungarian 20th International Conference on Mechanical Engineering Kolozsv r Romania 2012 04 19 201 2 04 22 Andras Fut Power Supply Unit of a Gerdien Condenser based ion spectrometer Hungarian Scientific Student Conference Budapest University of Technology November 2012 Andras Fut awarded the 2 prize in Hardware Section http tdk bme hu VIK DownloadPaper Gerdien kondenzatoros ionspektrometer Oral presentations Zsolt V radi The REXUS Gekko experiment Hungarian presentation in the 10th Hungarian Youth Forum organised by the Hungarian Space Office and the Hungarian Astronautical Society Agnes Gubicza Study of the variation in air conductivity with altitude presentation in a physics seminar at Budapest University of Technology and Economics Hungarian Zsolt V radi The Gekko rocket borne experiment Hungarian presentation in the 28th lonosphere and Magnetosphere Physics Seminar
102. ngineering Plastic Products global leader in engineering plastics for machining Www quiadrmsntplastics com RX14 GEKKO SEDv5 0 9aug13
103. nterfaces TV channel required If yes when is it required lt D o Up Downlink RS 422 required Data rate downlink 6 5 Kbit s 0 1 Kbit s Data rate uplink Dl a O Power system Service module power required Yes Peak power consumption Average power consumption Total power consumption after lift off 0 16Wh until T 600s Power ON 600s before lift off Power OFF 600s after lift off Battery recharging through service module Experiment signals Signals from service module required Yes LO Yes SOE 26s after lift off SODS RX14 GEKKO SEDv5 0 9aug13 Page 115 EuROLAUNCH 6 1 4 Launch Site Requirements The required equipments tools and infrastructural stuffs from the launch site are listed below e a2230V 50Hz power outlet e 1 desk size 120 x 75 x 60 width x height x depth e 3 chairs e internet connection e DC Power Supply with 28V 100mA adjustable output e screwdriver set e soldering station 6 2 Preparation and Test Activities at Esrange Experiment preparation After the module is integrated the Gekko experiment is ready for operation To prepare the experiment for the hot countdown only the RXSM interface is used Replacement of any part of the hardware is not considered The condensers and the electronic box will be already attached to the rocket when the payload is shipped to Esrange RX14 GEKKO SEDv5 0 9aug13 Page 116 EUuROLAUNCH
104. nthe event that the Gerdien condensers are mounted at the base of the payload please inform us at which distance from the external module skin will they have to be mounted to avoid the turbulent flow region o Please be aware that the nosecone will detach from the payload at T 60s This will seriously affect the air flow characteristics of the RX14 GEKKO SEDv5 0 9aug13 Page 143 EUuROLAUNCH payload so it is recommended that you take this account Please ensure that the Gerdien condenser mountings are as aerodynamic as possible so as to reduce instabilities It is recommended that you manufacture the mountings from solid aluminium and that they take on the form of a wing leading edge You will most likely be assigned a small experiment module so please ensure that you have adequate room for your mountings When conducting your thermal analysis please note that the re entry temperature of 200 C quoted in the RX User Manual is an upper case value In reality it is closer to 100 C This is worth keeping in mind when selecting your external component materials The capacitors to be used for your Gerdien condensers will produce significant heat Please be aware that this may have an impact on your measurements The Gerdien condenser mountings should also act as a heat sink to avoid over heating the sensors Chapter 4 will require elaboration prior to submission of SED v2 0 Please include as much information as possible especiall
105. of M6 bolts in each condenser e 2 pieces of M6 nord lock washers in each condenser e 2 pieces of M4 bolts in each condenser e 2 pieces of nord lock washers in each condenser Electrical box e 6 pieces of M4 bolts e 6 pieces of M4 nord lock washers e 6 pieces of card lock retainers Experiment centre of gravity can be adjusted to coincide with the geometrical centre of the rocket if necessary 4 2 2 Electrical The external electrical interfaces of the Gekko experiment are the following 28V Power interface RS422 data interface and the LO and SOE control signals provided by the RXSM experiment interface connector The interface circuits are presented on Figure 13 28V 28V 3V3 R1 R2 10 U1 3k3 C LO LO SOE 28V GND 28V GND Figure 13 Control signal IF circuits RX14 GEKKO SEDv5 0 9aug13 Page 38 EUROLAUNCH The data rate is 1200kbps on the downlink The uplink channel is used for send TC and upload the bias voltage values into the onboard memory before flight A DSUB25 type connector technology IF connector is used for testing the experiment and programming the microcontroller This connector is unavailable after the payload integration Figure 14 shows the connection method of the triaxial cables The inner conductors and inner shields of the cables are connected to the electronic box by two TNC connectors The outer shield is connected by cable lugs as shown on the picture Figure 14 Connecti
106. on of the triaxial cable The connections at the condenser side are shown on the next pictures The inner conductor of the cable is led inside the pipe and connected to the inner electrode The role of the inner shield is to guard the inner conductor to RX14 GEKKO SEDv5 0 9aug13 Page 39 EuROLAUNCH reduce leakage current This layer is galvanically isolated not connected at the condenser side The outer shield is soldered to the outer electrode and the connection is covered by a heat shrink tube d Figure 15 b Connection of the condenser Figure 15 c connection of the condenser Inside the electronics box the DSUB connectors are wired to the motherboard with PTFE Habia cables see figure 16 The TNC bulkhead connectors are assembled with RG316 U coaxial cables that end in SMA connectors as shown in figure The SMA connectors are directly connected to the analogue electronics PCB The bias voltages outer shield of the triaxial cable are also wired directly to the analogue PCB by using cable lugs and copper wires with PTFE insulation The datasheets of the cable assembly components SMA PCB gt SMA angle plug RG316 U coaxial gt TNC bulkhead gt TNC plug gt triaxial are included in APPENDIX C RX14 GEKKO SEDv5 0 9aug13 Page 40 YO EuROLAUNCH y 4 Ma e H d Figure 16 Cable connection in the electronics bo he internal connections between the PCBs are implemented on the motherboard The PCBs are p
107. on table please see end of data sheet or Appendix C of Burr Brown IC Data Book ABSOLUTE MAXIMUM RATINGS Internal Power Dissipation Differential Input Voltage 3 Input Voltage Range 65 C to 150 C 40 C to 125 C Storage Temperature Range Operating Temperature Range Lead Temperature soldering 10s Output Short Circuit Duration Junction Temperature NOTES 1 Stresses above these ratings may cause permanent damage 2 Packages must be derated based on 8 4 90 C W for PDIP and 100 C W for SOIC 3 For supply voltages less than 18VDC the absolute maximum input voltage is equal to 18V gt Mu gt Vcc 6V See Figure 2 4 Short circuit may be to power supply common only Rating applies to 25 C ambient Observe dissipation limit and T ELECTROSTATIC DISCHARGE SENSITIVITY This integrated circuit can be damaged by ESD Burr Brown recommends that all integrated circuits be handled with appropriate precautions Failure to observe proper handling and installation procedures can cause damage ESD damage can range from subtle performance degrada tion to complete device failure Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications The information provided herein is believed to be reliable however BURR BROWN assumes no responsibility for inaccuracies or omissions BURR BROWN assumes
108. ond This means that a bias voltage is applied to the Gerdien condensers in a predefined voltage range and the current of the inner electrode is measured The physical background of the measurement method is detailed in chapter 1 1 The applied bias voltage range for each characteristic curve is defined taking into consideration the velocity and the altitude of the rocket the physical dimensions of the condensers and the estimated ion density and its distribution in the middle atmosphere above ESRANGE The actual velocity and altitude are not available real time therefore the measurements are scheduled according to the elapsed time Using this method the recorded mobility spectrums have time dependence instead of altitude dependence The approximated flight profile including the v t TO and h t TO functions are provided before the launch campaign by the EuroLaunch The estimation of the ion composition is based on former studies of the atmosphere 8 13 14 Table 35 shows the calculated bias voltage sweeps with 5 km resolution Table 35 Bias voltage ranges bias voltage range V ERN positive ions negative ions Vas Vas 1 12E 02 1 03E 02 4 92E 01 4 50E 01 2 19E 01 2 04E 01 9 73E 00 8 99E 00 4 54E 00 4 15E 00 2 18E 00 2 01E 00 1 12E 00 5 538E01 5 60E 01 151 3 42E 02 3 83E 02 3 54E 02 3 54E 02 80 2 00E 02 EE NEN QUEM 90 3 21E 03 RX14 GEKKO SEDv5 0 9aug13 Page 122 EUuROLAUNCH Sin
109. ooperation There seems to have been a reduction in information available in software please re include this information Update the issued by on the cover page Update the references section Pg 1 uses the old EuroLaunch logo please update this Pg 2 uses a standard text from the SED guidelines please replace it bya short description of your team and project Pg 5 in the abstract you refer to a launch at the polar cap please change this to the polar circle or similar Pg 18 the legend for the Gantt chart is missing please include this Pg 71 Please do not use centimetres but millimetres Pg 73 when using figures from the manual please reference them Pg 82 some incorrect abbreviations not your fault these will be updated in the SED guidelines 4 Panel Comments and Recommendations Requirements and constraints pter o Use minimum accuracy not maximum accuracy Mechanics hapter 4 2 1 amp 4 4 Oo Please include a ae sketch of the whole module top side view etc with basic dimensions including overall height dimensions of condensers and spacers If your outer structure is bespoke this should be included and detailed in your mechanical section Please use nord lock washers In general the analysis is not complete enough at a minimum the two M6 screws should be included The FEA boundary conditions are not clear be careful when using figures from the user manual you still need to implement yo
110. opagation oldhat delay iio ER ER RR Gite eines 4 7 ns m Working voltage AC Famis onec Naa 1000 max Working voltage DC 2000 max Attenuation typical values see table Nominal values at an ambient air temperature of 20 C Power typical values see table Ambient temperature of 20 C at sea level and VSWR 1 0 Suitable for frequencies Minimum bend radius MBR Minimum bend radius MBR up to 2 5 GHz single bend 15mm multiple bends 30mm Operating temperature 55 4200 Flame resistance passes IEC 60332 3 Cat A PMID LLL R SZES nce eei cus Uh iu PU tU aed passes UL 94 V 0 Connectors compatible with all standard types Data provided indicates nominal values unless stated otherwise and is only valid for reference purposes at the time of publication and is subject to change without prior notice These products are manufactured generally in accordance with the Mil Spec in terms of design parameters and performance Habia are not qualified to release product to the appropriate QPL www habia com World Class Solutions Ref CC eRG316 01 Date 2005 02 24 RX14 GEKKO SEDv5 0 9aug13 Page 177 EUROLAUNCH A DLR and SSC cooperation r Telegartner 1 2 KARL GARTNER GMBH order number J01011A0058 TNC Bulkhead Jack Crimp G7 RG 316 U solder crimp with seal ring barrier sealing Technical Attributes Cable group cable G7 RG 316 U Remarks 000 solder crimp with panel and barrier sealing Crim
111. orinczi Botond Dr Banfalvi A e box back plate Electronics box back plate F Figure C8 Gekko Electronics box back plate RX14 GEKKO SEDv5 0 9aug13 V Page 165 EuroLAUNcH A DLR and SSC cooperation V 45 dk Figure C9 Gekko Electronics box front plate RX14 GEKKO SEDv5 0 9aug13 dhk Page 166 EUuROLAUNCH V 129 V Figure C10 Gekko Elecronics box base plate RX14 GEKKO SEDv5 0 9aug13 Page 167 EuROLAUNCH V V Figure C11 Gekko Electronics box top plate RX14 GEKKO SEDv5 0 9aug13 V Page 168 EuROLAUNCH H AU Wd E E D ge ES Fe ES CR ES E REZZA ZZ ZS igned by Checked b Approved by Date al Lorinczi Botond Dr Banfalvi A 012 Gekko e box PCB holder plate Electronics box PCB h 1 dk Figure C12 Gekko Electonics box PCB holder plate left RX14 GEKKO SEDv5 0 9aug13 dhk Page 169 EuROLAUNCH V 2 UI AE V Iw eE Ale igned by Approved by Date at Lorinczi Botond Dr Banfalvi A Gekko e box PCB h mir Electronics box PCB h mir dk Figure C13 Gekko Electonics box PCB holder plate right RX14 GEKKO SEDv5 0 9aug13 dk Page 170 EUuROLAUNCH V CC 1 1 B 1 1 ql 1l Figure C14 Gekko bulkhead manufacturing drawing RX14 GEKKO SEDv5 0 9aug13 IS EUROLAUNCH age 171 D s us Ss d NW
112. osts contribution to launch costs not included Table 2 Budget fm Mechancis Connectors Cables Note The budget does not include the costs of vibration test it is available for free at EL TECH Center Ltd 3 2 3 External Support Dr P l Bencze Geodetic and Geophysical Institute Sopron Support definition of scientific objectives description of the physical environment processing measurement data Dr J zsef Szab Budapest University of Technology and Economics Department of Broadband Infocommunications and Electromagnetic Theory Space Research Group BME SRG Support electrical design and testing Dr Antal B nfalvi BME SRG Support mechanical and thermal design Dr Laszlo Csurgai Horvath Suport digital hardware and software development Hungarian Space Office Financial support RX14 GEKKO SEDv5 0 9aug13 Page 27 EuROLAUNCH 3 3 Outreach Approach The progress of the development and the scientific results gained from the experiment will be published in Hungarian scientific magazines and space related news portals The scientific results and engineering experiences will also be presented at national and international conferences and in scientific publications Our public relation strategy is based on the team website and the facebook page of the team The website contains all relevant information about the background and the progress of the experiment the team members and the Supporti
113. p die N01003A0009 Assembly A4016 Product description The TNC series is a commonly used coax connector The same size as BNC connectors but with a threaded coupling mechanism this connector can be used up to 11 GHz Both 50 O and 75 O impedances are available Connector styles are available for flexible conformable and semi rigid cable types Versions of the TNC connector are available for mounting to printed circuit boards using both through hole soldered and through hole press fit techniques Both crimp and clamp cable termination processes are used for this series Applications for these connectors range from signal and data to video transmission where vibration resistance is required TNC s are a low cost high frequency solution for coax connections Mating face sealing for TNC connectors between plug and jack mated according to IP 68 The classifications are general statements for the relevant series Individual connectors may deviate from the values shown If in doubt please consult our engineers Note O 2013 Teleg rtner Karl G rtner GmbH Technische Anderungen vorbehalten Technical changes reserved www telegaertner com Lerchenstr 35 D 71144 Steinenbronn Tel 49 0 7157 125 100 Fax 49 0 7157 125 120 E Mail info telegaertner com RX14 GEKKO SEDv5 0 9aug13 Page 178 EUROLAUNCH A DLR and SSC cooperation r Telegartner 1 4 KARL GARTNER GMBH order number J01010A2608 TNC Straight Plug G1 RG 58C U
114. ration for Space Standardization ECSS Space Engineering Technical Requirements Specification ECSS E ST 10 06C 6 March 2009 European Cooperation for Space Standardization ECSS Space Project Management Risk Management ECSS M ST 80C 31 July 2008 European Cooperation for Space Standardization ECSS Space Engineering Verification ECSS E ST 10 02C 6 March 2009 Project Management Institute Practice Standard for Work Breakdown Structures second Edition Project Management Institute Pennsylvania USA 2006 David A Burt The development of a Gerdien condenser for sounding rockets Scientific report no 8 University of Utah 1967 Murray J McEwan and Leon F Phillips Chemistry of the atmosphere Wiley New York 1975 V V Smirnov V F Radionov A V Savchenko A A Pronin V V Kuusk Variability in aerosol and air ion composition in the Arctic spring atmosphere Atmospheric Research Volume 49 suue 2 1998 Bragin J A Tulinov V F Smirnih L L Jakovlev S G Simultaneous measurement of the ion concentration and intensity of cosmic ray in the height range 10 70 km in Russian Kosmicheskie Issledovanija X1 488 489 19723 REXUS User Manual Document ID RX REF RX user manual v 06Sep12 RX14 GEKKO SEDv5 0 9aug13 Page 140 EuROLAUNCH 13 Beig G Global change induced trends in ion composition of the troposhere to the lower thermosphere Ann Geophysicae 26 1181 1187 2008 14 F
115. rature level 40 25 and 470 degrees RX14 GEKKO SEDv5 0 9aug13 Page 4 EUuROLAUNCH Table 16 Thermal test Test type Thermal Test facility Thermal chamber at BUTE Tested item Flight model Test level procedure System level Acceptance test 4hrs and duration Verified Requirement F2 F3 F5 F7 D2 D10 D12 O1 O4 O7 The test objectives This test is to verify that the experiment is working properly Both static and dynamic measurements are performed at 3 different temperature level 40 25 and 470 degrees Table 17 Vibration test Electronics box Test number Test type Vibration transient and sinusoidal Test facility EL TECH Center Budapest Tested item Electronic box flight model Test level procedure System level Qualification test 4hrs and duration Verified Requirement D1 The test objectives This test is to demonstrate that the mechanical calculations are correct The box can withstand without damage under the vibration test is carried out in accordance with the requirements of the rocket Table 18 Vibration test Gerdien condensers Test number Test type Vibration transient and sinusoidal Test facility EL TECH Center Budapest RX14 GEKKO SEDv5 0 9aug13 Page 75 EUuROLAUNCH Test level procedure System level Qualification test 4hrs and duration Verified Requirement D1 The test objectives This test is to demonstrate that the mechanical calculations are
116. re Because of your design it is suggested you include a diagram description of safe handling and holding points can we pick the module up by the condensers for example Also include this in chapter 6 Consider how we can work on the module does it sit on a bench like the other modules or do we use a mount Also include this in chapter 6 There is a risk during re entry that your condensers act like wings and cause some gliding to the rocket research and include this risk Consider the risk of parachute entanglement with condensers Be sure to include the risks associated with the HV system RX14 GEKKO SEDv5 0 9aug13 Page 150 9 NN N 4 A 2 d Li EUROLAUNCH A DLR and SSC cooperation Launch and operations SED cha o See above for safe handik and working points o Please include a full plan of operations including preparation activities with people responsible etc See the SED guidelines for more on this Include a safe handing procedure when HV is powered on Be aware that people will view the HV system as a risk be sure to include safety measures in general in this section Think about how long after power off until the module is safe to handle think about the recovery and include this in this chapter Table 22 needs to include total mass including bulkhead and module Be aware the flight simulation is planned for ESRANGE change your SED to reflect this Don t reference other sections in chapter
117. re only Beer thin data eheestnagr any da and epecd cadicm presentedon our webalte shall create ar ba impleti create my legi oar contactual obligation Any usaian of tha pomble Jaki a applicition of the Products shal merely demonstrate the potential ei these Pradicii but any mich description dass nat gm iuis any kind oi gengt whatsoever infeed five ch ang Duae iet Cady apt mas hive carries ail lih apd bs any Fradud Ciaran daas nal pore expertis n svaluatim the adabli of a materiale er Produsta for use Io ipods applicaism or producti manica or olai by Hos cus merae paisisictiveby The ahelos of the most cutee plastica maaa dean on avallabla dhenkal da Ear data and patie spana but aun praliminarg padri d the iishal plantics part under acual naria conditions ght chemical aanrada terrgparatura and centet hir aa well au Other aonditiomo a ragad po am enn ia Anal audtatil y for tha gin applioatien D dus mimi ha Giusti sack pepe 5s bas and aaen fhe Bite ond comp bly of Canafran e Praida Go Ip heal sgricatong pitones ard ijn amisi che theme Product which aicerding bi iim ween met Hur agamane appela ta the adk ume o the nin bad prafus Tha customer urcdartsken al liability in rampact i Ha ap kalen pracausirg or ume of the alaremendjenad Infemalian ar predict ar any conesquance Her aci amd shall arity ji qinlly and dhaj prepares Copyright e 2011 The Quadrant group of companies All rights reserved Date of Iesue revision Aper 24 2011 Quadrant E
118. rocket wall is 100 C according REXUS manual The results show that the spacer can cool down the condenser effectively Assuming only 100 C on the condenser surface there is no need of modifying the plans however our possibilities in the choice of soldering material broaden we can focus on electrical properties of soldering materials instead of the melting point temperature Figure 44 Temeprature distribution of the condenser RX14 GEKKO SEDv5 0 9aug13 Page 90 EUROLAUNCH A DLR and SSC cooperation Figure 45 Heat flux distribution of the condenser The exact boundary conditions are to be determined based on related literature or further discussion with endorsing professors or experts from the organiser space agencies RX14 GEKKO SEDv5 0 9aug13 Page 91 EuROLAUNCH 5 3 3 FEM analysis of airflow verification of D 17 During the finalization of the mechanical design we discussed with the experts from DLR MoRaBa one of the main issues was the effect of the condensers on the rocket trajectory The discussion concluded in the result that the condensers have no relevant influence on the rocket trajectory It is indeed true that the wedge shaped struts create more lift than ones of circular cross section but the struts are not big enough to mesmerize the mission Thats why we focused on the airflow characteristics inside the condensers Depending on the airflow velocity we can adjust the bias voltage of the
119. ronic content in the SED was very good as was the Requirements Verification and Testing sections o The SED preface is included in the template for your reference only For future versions of the SED you should either delete this section or write a preface that is relevant to your experiment Presentation o The presentation was generally well delivered with good timing It was clear concise and provided some clarification on the mechanical design The team engaged well with their audience o t was noted that there were some discrepancies in the mass estimates provided in the SED and the presentation Please try to be consistent in the information you provide to us 4 Panel Comments and Recommendations Requirements and constraints SED chapter 2 o The Requirements and Constraints section of the SED was very good The panel commend you for this o Please be careful with the use of should and shall when describing your requirements Make sure these are correctly classified Mechanics SED chapter 4 2 1 amp 4 4 o The aerodynamic effects of the Gerdien condensers on REXUS 14 s flight profile are a major concern If the experiment is mounted too far forward in the payload it will almost certainly create instabilities To mitigate this effect your experiment will have to be mounted toward the base of the payload You should seek further advice from EuroLaunch regarding module placement and associated air flow characteristics o I
120. ss s law and the differential Ohm s law we get the following equations E Q yrs J 1 2 6 D un o So we get J Q Q B e I o o Se e 1 2 7 where J is the current density is the current S4 is the surface of the inner electrode Q is the charge of the ion and c is the air conductance which equals o nqu q is the charge of the ion Because of Q CV can can write CV 2aVL 1 2 8 o qi Hi LN Eo vi a Finally the minimal and the saturation current the measurement range can be determined From the expression of the current 1 2 8 and the mobilities 1 1 9 we get requirement 3 Ideal and real characteristics The ideal voltage current characteristic of negatively charged ions is shown in figure 3 RX14 GEKKO SEDv5 0 9aug13 Page 12 EuROLAUNCH U Figure 3 Ideal voltage ampere curve When the bias voltage is increased more and more ions with mobility greater than the critical mobility are captured until the saturation current is reached I GV 270 L V HOA V vi E 1 3 1 a where G is the conductance of the condenser unit o is the conductance of the air n is the number density and yj stands for the mobility of the ion The slope of the linear region is the conductance Gj If the air consists of more ion groups the characteristic will looks like that in figure 4 It can be seen that there are breaks at different points where the slope of the curve changes These indicate th
121. t a breakpoint we get a mobility value which corresponds to a certain molecular weight The last step is the identification of the molecule by its molecular weight After the launch campaign we will perform a scientific analysis involving scientific data obtained by Scandinavian observatories The results will also be compared to results of former sounding rocket measurements 13 14 RX14 GEKKO SEDv5 0 9aug13 Page 123 EUuROLAUNCH 7 2 Launch Campaign The launch campaign took place on CW 18 19 2013 Three students participated from the Gekko team on the launch campaign G bor Balassa science tests ground station operation Ott Botond L rinczi mechanics tests failure analysis Zsolt V radi electronics tests ground station operation failure analysis The REXUS 14 was launched on the 7 of May 2013 at 8 00 am Due to a failure the Gekko experiment was not able to take measurements and therefore the scientific objectives of the experiment were not fulfilled 7 2 1 Flight preparation activities After setting up the GSE we performed mechanical checkout of the experiment We haven t found any damage or loose screw The electronics box as well as the condensers were clean he experiment was powered and functional test was performed with the GSE During the functional test normal HK data frames were received After updating the on board software the experiment was ready to perform the individual test with the RE
122. tages will decrease As a conseguence of the current mode control and the fixed switch off time the input current decreases when any of the outputs are shorted The switching power supply will have a nominal switching frequency of 50 kHz The switch off time is fixed to 25 usec The L3 inductor ensures that the maximal voltage ripple fed back to the RXSM never exceeds the allowed 500 mVpp level The 28V power line series resistance is considered 1 3 O and the series inductance is 64 UH The UVLO starts the power supply if the input voltage is above 23 V and it disables the operation when the input voltage decreases below 20 V The complete control circuit of the power supply will consume a maximum of 20 mA During start when powered from the 28 V input this translates to 560 mW This decreases below 200 mW during normal operation The inrush current of the power supply is limited to maximal 250 mA by an FCL foldback current limiter circuit this intervenes via MOSFET Q1 The flyback transformer is coiled by us The transformer has seven galvanically isolated secondaries including a high efficiency auxiliary power supply for the control circuit 4 5 2 Analogue electronic board The analogue electronic board contains the required circuits for biasing the condensers and measuring their currents This PCB is interfaced to the motherboard by a 96pin B2200 R960 type connector see figure 9 Because of the expected ion density and the
123. the effects of the modifications were as expected Due to the additional struts the stiffness of the structure increased as well as the natural frequencies except for the inner spacer where no modifications were made The stress decreased however the applied material stainless steel 440 is much stronger than the previously applied aluminium alloy RX14 GEKKO SEDv5 0 9aug13 Page 83 EUROLAUNCH The test results for the x axis peak acceleration Is 240 me Table 25 Analysis results x axis Frequency Hz 1535 1980 Max Deform 47107 42 10 Max Strain 3 95 107 3 08 107 LLL LL tz 1 063e7 4 249e6 1 72e6 8 498e5 ut 223465 c 0 100 m er T 0 025 0 075 Figure 39 Maximal stress response x axis The maximal stress occurs in the welds of the struts however the value of 17 07 Mpa is lower than the yield point of the used material nearly by two orders of magnitude the stress in the bolts are also negligible RX14 GEKKO SEDv5 0 9aug13 Page 84 e EUROLAUNCH A DLR and SSC cooperation The test results for the y axis peak acceleration is 130 me Table 26 Analysis results y axis Frequency Hz 1150 1890 3 63 10 T3710 1 72 107 4 58 10 1 06 10 4 73 10 Max Stress 41 2 MPa 18 55 MPa 5 08 MPa 5 89266 1 742e6 1 913e5 113 7 Min 0 025 Figure 40 Maximal stress response y axis In this case the maximal stress occurs in the weld of the main spacer T
124. the rocket the axis of the roll the maximum condenser length is 300 mm Considering the minimum velocity of 250 m s therefore the particles pass through the condenser in 1 2 ms time The linear velocity based on the data above is 5 02 m s In 1 2 ms the condenser clears 6 024 mm distance perpendicular to the travelling direction of the rocket This means the condenser clears 27 38 of its diameter laterally while a particle passes through In my opinion that strongly influences the measurement therefore at the top of the trajectory the measurement results will not be confident In the following narrow the measurement range on one hand due to the above mentioned effect on the other hand because the average free path length of the particles at the altitude of 100 km is in the same order of magnitude with the sizes of the condenser that could lead to further difficulties Finally as the rocket approaches the summit of its trajectory its orientation becomes more and more indeterminate thus the airflow may not be parallel to the longitudinal axis of the condenser Narrowing the measurement range to altitudes 25 80 km the free path and orientation problems are eliminated the velocity varies between 600 1200 m s the value of the roll frequency is approximately 3 7 Hz Calculation results obtained using the new data the pass through time is 0 5 ms the linear RX14 GEKKO SEDv5 0 9aug13 Page 101 EuROLAUNCH ve
125. the same condenser The order of these steps is the following 1 SET DA bias 2 START ADC CH3 Bias WAIT to AD read READ AD CH3 Bias 3 START ADC CH4 Current WAIT to AD ready READ AD CH4 Current 4 SET DA2 bias 5 START ADC CH1 Bias WAIT to AD ready READ AD CH1 Bias 6 START ADC CH2 Current WAIT to AD ready READ AD CH2 Current The converted data bytes are stored in the internal SRAM until a whole frame is ready The transmission to the ground station is initiated when the frame is ready The HK data frame is generated in every five seconds Each data packet is equipped with a time stamp which is extracted from the clock counter during frame assembly A table of periodic processes during the mission is shown below Status monitor stand by prepare BEEN Nominal HK 5s continuous Access to RS422 60 ms nominal mae mn 10ms transmission RX14 GEKKO SEDv5 0 9aug13 4 9 Page 65 EuROLAUNCH Ground Support Eguipment The GSE shall be able to support the pre flight tests including troubleshooting and hardware tests simulate the service module upgrade the on board SW and support the operator to inspect and control the experiment Thus the Gekko GSE consists of a REXUS service module simulator and a break out box built up on a common panel see figure 32 an experiment IF cable assembled with DSUB 15 male female connectors a Ground Station IF cable assembled with DSUB
126. tly possible boards are not all ready the tests possible to do worked well Others e Hardware will be ready at the end of 2012 RX14 GEKKO SEDv5 0 9aug13 Page 158 EUROLAUNCH A DLR and SSC cooperation REXUS e Experiment Acceptance Review EUROLAUNCH Page 4 e Test finished mid of January maybe 1 week e Delivery should be possible end of January FINAL REMARKS Summary of major actions for the experiment team e Finishing the mechanical mounting e Finishing the electronics hardware end of 2012 e Fulfilling tests thermal PSU flight model amplifier flight model full system thermal test first week of january e Shaker test at university to be done before delivery EAR Result pass conditional pass fail e Conditional pass Next SED version due e 16 Dec but not the whole test results or later with test results Summary of actions for EuroLaunch e Precise trajectory after flight required e Nothing special for preflight and recovery RX14 GEKKO SEDv5 0 9aug13 Page 159 EuROLAUNCH APPENDIX B OUTREACH AND MEDIA COVERAGE Gekko Team web site http lab708 mht bme hu gekko Gekko on Facebook http www facebook com GekkoTeam Publications and presentations e gnes Gubicza Study of the variation in air conductivity with altitude presentation in a physic seminar at BUTE http www phy bme hu jakovac Eloadasok Gubicza Agi gubicza diak pdf e Zsolt V radi Hungarian experiment in t
127. to thermal analysis has been very good to date However it is recommended that you look into the thermal properties of the electronics box and compare them against the REXUS temperature profiles to ensure your experiment will operate at its optimum temperature o It is recommended that you perform thermal simulations using Ansys Or a similar system to assess the thermal characteristics of the Gerdien condensers and their mountings o It is recommended that you provide a table outlining the thermal ranges of individual components a Software SED chapter 4 8 o It is not necessary to use mutex if you do not require real time control or telemetry o Please ensure that data stored on your flash memory cannot be overwritten or corrupted in the event of glitches power cycling or hard cuts during flight It was noted that you have expressed an estimated flight time of 5 minutes Please be aware that the nominal flight time for REXUS experiments is 600 seconds We can power down your experiment when required but the exact timeline will have to be calculated and defined well in advance o The software flow diagrams presented in the SED were good but it was noted that there were no m alive signals incorporated into your software It is recommended that you include this Verification and testing SED chapter 5 o Your approach to verification and testing was generally well thought out However please pay close attention to your v
128. ults The method determining the coverage temperature empirical formula T cover To 1 0 174 M RX14 GEKKO SEDv5 0 9aug13 Page 59 EUuROLAUNCH Where e cover Is the temperature of the coverage K e ois the air temperature K e Mis the Mach number current velocity of rocket The air temperature is more important in the lower altitudes where the density is higher In addition the maximum velocity of the rocket is at the altitude of 24 km This point is approximately at the top of the tropopause where the temperature is 56 C 217 K Thus the data is as follows To 217K The coverage temperature Tcove 217 1 0 174 3 557 K 283 C This formula does not take the heat transfer processes into account so it can be considered as an estimate regarding the condenser walls For the inlets the boundary conditions are much more complicated and higher temperatures can be expected Considering the low melting point temperature of soft solders and structural polymers great care must be taken choosing the materials during the development final verification can be carried out based on material data simulation and thermal test The results of finite element thermal analysis can be found in chapter 5 3 4 7 Power System The Gekko experiment will be powered on the 28V power line from the REXUS service module No additional batteries will be used The experiment power will be switched on and off by th
129. unch campaign came to its end We have presented our preliminary results on the Post Flight Meeting The reason of the short circuit and the very high input current was found When we left ESRANGE we still didn t know the reason of the damage of the voltage reference IC The investigation continued at the university By studying the PSU board with microscope we have found that not only one pin but 6 other pins touched the structure The next figure shows the components which shorted to the electronics box RX14 GEKKO SEDv5 0 9aug13 Page 132 EUROLAUNCH A DLR and SSC cooperation NR HR MUN mm Ai HIE IEE Last number IC7 T7 D25 TR1 L19 C78 R60 Figure 58 Pins that are shorted to the structure The pins of the components on the PSU board were cut after soldering therefore the cutting edges are clearly visible under the microscope In case of those pins that hit the electronics box the edges lost their sharpness The next picture figure 59 was taken in oblique light It is clearly visible that the pin of R20 where the high curr
130. ur own Safety factor on top of these You include results from the thermal analysis without real figures please include the numbers here along with comparison of the material and design limits and the safety factor Please include the cable feedthrough and the D SUB bracket Y ou need to update your mechanical design following the comments from the panel about your spacers you should follow the advice from DLR MORABA Specifically you should include e Additional struts at the extremities of your condensers with a smooth transition surface Increase the length of your module to 300mm Do not use the upper part of your module as this will contain balance weights e Keep in touch with the experts whilst performing this new design follow their advice You should also consider e The additional struts should be welded to the condensers take care of the precise alignment with the rocket longitudinal axis The struts should also be connected to the module by a screw from the inner side of the module in a similar fashion to your central spacer e Your strut thickness should be gt 8mm if you use a circular cross section e Consider the use of nord lock washers it saves on Loctite e You must now use a wall mounted bulkhead with a 300mm module a Electronics and data management lt hapter 4 58 amp 4 3 Include the interface to the REXUS fiddle wie this more detailed with a schematic Please include filtering in the power supply as mentioned
131. ure 20 b Electronics box assembly Current mechanical drawings of the gerdien condensers are accessible in the appendix of the Student Experiment Documentation RX14 GEKKO SEDv5 0 9aug13 Page 47 EUuROLAUNCH 4 5 Electronics Design 4 5 1 Power Supply Unit The power supply of the experiment will be located on a separate panel It will be implemented as a flyback converter using magnetic feedback and current mode control with fixed switch off time The control circuit uses discrete components power MOSFET switches and bipolar analogue integrated circuits including operational amplifiers comparators a voltage reference and a 555 timer chip for the fixed off time Each output will be filtered using common mode and differential mode filters Foldback 15 V current limiter DM filter Monostable multivibrator Vaux for control circuit 28V BUS from RXSM Ge 5 JE 7 DM 5 S 15 V m y ls E DM o E 1905 a15 V 9 120 V 9T 15 V Current comparator fil 9 Ge CR N7GND3 9120 V Voltage error amplifier g9T3 3 V niin Sof ES ni DGND Eme a 2 5 V We Lm ridi NZAGND 2 2 5 V 9 5 V g V Figure 21 PSU block diagram Note that 60 outputs are used instead of 120V RX14 GEKKO SEDv5 0 9aug13 Page 48 EUuROLAUNCH The PSU provides stabilized supply voltages for the analogue and digital electronics including a HV output 60V
132. uring lift off would not mean the total loss of an experiment 7 4 Lessons Learned The Gekko project provided us a lot of experience even if the scientific objectives were not fulfilled The most important lessons that we learned are as follows RX14 GEKKO SEDv5 0 9aug13 Page 136 EuROLAUNCH Proper project management is essential to a well done experiment and it takes a lot of time A good and updated Gantt chart can help a lot For those students who did not receive academic credit for their work it was very hard to take the time to work on the development On the other hand the students who worked for credits as part of their thesis or project laboratory put a lot of effort in accomplishing their tasks For BSc and MSc students the exam term shall be highlighted with red on the Gantt chart as they clearly won t be able to dedicate enough time for the development during these weeks This affects not only the development of the experiment but the workshop training participation as well Itis very important to perform tests and simulation as early as possible We could have saved our time and money if we carried out one of our simulations earlier In any case it s better late than never Sometimes we had to repeat a test because every result was documented but the test conditions were not Breadboards are important With the use of breadboard models we didn t have to re design any PCB thus saving us
133. void the turbulent boundary layer Thickness of the boundary layer against the distance from the rocket tip 0 08 0 07 0 06 0 05 0 04 0 03 1 4 1 9 2 4 2 9 3 4 Distance from rocket tip m Thickness of the boundary layer m Figure 49 Thickness of the boundary layer against the distance from the rocket tip Calculating the needed distance a safety factor of 2 has been used thus the distances on the figure are twice the values of the strictly needed distances Based on these results at the base of the payload a distance of 60 mm would be preferable but theoretically the previous distance of 40 mm is still adequate Increasing the distance would lower the resonance frequencies of the condensers and possible hazardous stress may occur in the structure RX14 GEKKO SEDv5 0 9aug13 Page 98 EuROLAUNCH For the 40 mm distance the strength of the structure is appropriate If a decision is made on increasing the distance to 60 mm new finite element analysis will be required for verification An additional aspect for aerodynamics is that the struts that shall prevent parachute lines from entangling with the condensers at the extremities of the condensers may act like wings so the rocket will behave as a glider during the descending phase causing unwanted stability The design of our struts has been devepoled in cooperation with experts from DLR in conclusion the overall opinion was that the aforementioned risk
134. w chart Task 3 1 1 Gugyin Implementation Task 3 1 2 3 1 5 Optimalization Task 3 1 6 Flow chart Task 3 2 1 Balassa Implementation Task 3 2 2 3 2 5 Optimalization Task 32 6 Varadi Application Define budget Arrange LOC Keep active contact Lorinczi and Varadi Coordinate group work Arrange test activities Arrange reviews and training participation Balassa L rinczi Varadi Publish scientific results in papers Publis activities in paper and electronic press Design Task 5 3 1 Start and update Task 5 3 2 Publish activities on Facebook Varadi Gugyin Perform post process Balassa Analyse results Balassa Varadi Write final report Figure 8 Schedule Legend blue completed red to be completed behind schedule grey to be completed orange line delivery deadline RX14 GEKKO SEDv5 0 9aug13 Page 25 EUuROLAUNCH 3 2 Resources 3 2 1 Manpower Table 1 Manpower Por CDR TPR EAR Delivery Launch Symposium 2011 12 2012 02 2012 06 2012 09 2012 12 2013 01 2013 05 2012 02 2012 06 2012 09 2012 12 2013 01 2013 05 2013 06 Gabor 4h w 4h w 2h w 4h w 20h 40h Balassa gnes 20h 2h w Oh Oh Gubicza Andr s 12h 6h w 35h w 4h w Fut Adri n 4h 2h w 3h w 2h w 15h 20h Gugyin mz mee e e Kollek m wm mw L rinczi D vid graduated ozab V radi Mil n backup Trunk RX14 GEKKO SEDv5 0 9aug13 Page 26 EuROLAUNCH 3 2 2 Budget Experiment c
135. y with regard to experiment dimensions mass and footprint The internal layout of the electronics box should also be presented in detail along with FE and Modal analyses Electronics and data management SED chapter 4 2 2 4 2 3 4 5 amp 4 7 e Please be aware that you will be situated 1m away from S band RF transmitters when integrated into the RX14 payload This will almost certainly produce interference greater than the pA current flows you aim to measure It is strongly recommended that you conduct interference tests and use filtering on your input stage Please take care when designing your PCB Ensure that you have adequate shielding and that filters are put into place It is recommended that you test your electronics systems for RF interference also The panel acknowledged that you will not require SOE and SODS commands during flight TC will only be required before lift off The downlink requirements you have quoted 38 2 kHz with a 3 ms gap for data transfer are a little unrealistic Please reconsider and re define your requirements It is recommended that you re consider using uplink during flight in case you need to manually adjust your bias voltage in flight Please be aware that uplink capability is available to you Otherwise the electronics design is very good so far Keep up the good RX14 GEKKO SEDv5 0 9aug13 Page 144 EUuROLAUNCH work Thermal SED chapter 4 2 4 amp 4 6 o Your approach

Team Name: Gekko

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