SKYAERO v.7.6.1 User`s Manual - Rocket Science and Technology
Contents
1. 0 8900 drag coefficient 78 5398 reference area drag ft42 0 8700 drag coefficient 7 0686 reference area drag ft42 9 6211 reference area drag ft42 1 0000 drag coefficient Figure 8 Parachute Parameters 2 6 Stages The next tables are those pertaining to thrust drag and weight data about each stage There are 3 of these tables one for each stage simulated The first inputs required are the weight of the structure payload and propellant for each stage in Figure 9 The thrust table in Figure 10 is composed of two input columns One is for time from ignition and the other is for sea level vacuum thrust These values are obtained from the motor manufacturer test or thrustcurve org in Figure 11 An alternative source is the NAR data base at National Association of Rocketry website It is important to realize that the motor manufacturer will always give thrust at sea level not vacuum It is the responsibility of the user to input the correct thrust The other columns are calculated values and need not be modified See figure below for reference 6 www nar org Stage 1 1st rocket section Parameters Value Value if stage present Units Notes 10 0000 100000ji Propellant Weight aooo 42 0000 structure weight C 100000 40 0000 Payload weight attached to Stages 7 0800 7 0800 ator Burn Time FALSE s Delay to Fire First Stage Motor FALSE FALSE s Launch to 1st Stage Separation Figure 9 Weight2. 2 429 7 Tot Impulse Ns 10 477 5 10 243 7 10 481 5 Burn Time s 7 1 6 3 6 2 Download a Download Now Add to Outbox Data Graph Aerotech M1939 ALT4 format ThrustCurve org 2014 2250 v O o Thrust Newtons 4 4 4 0 1 2 3 4 Time seconds Alternates in Pounds large size Data File stand data 1998 www tripoli org a Burn Time 19 REM2 provided by ThrustCurve org Wiis Cie SC le Cee 20 Time ieee 40 53 20 Time Thrust 0 78 476 61 20 Time Thrust j1 31 95 60 20 Time fore trate G ee 20 Time Thrust 2 36 499 73q 20 Time Thrust 2 88 483 257 Cmm Thrust Table 20 Time Thrust 6 41 431 404 20 Time Thrust 3 93 375 429 20 Time Tnrust l4 45 307 48 i 20 Time Beitt iio mae 20 Time Thrust S S0 172 592 20 Time Thrust 6 05 2 0 9 20 Time Thrust 6 55 4 724 20 Time Thm 7 08 0 00q 61 Mass Fraction 0 62 m x 2 Isp l1b s lb 186 569 Figure 11 Data from Thrustcurve org 11 2 7 Miscellaneous The table in Figure 12 summarizes the weight and mass for each stage and at each phase This table is to help user to re check their input values and settings before running the program Figure 13 is the table for the simulation monitor It helps users track the simulation progress Phases Weight and Mass Data Figure 12 Weight and Mass Summary TRUE Press Esc or Break key to stop the simulation then clic
3. 15 4 FAQ Q I do not have as many Thrust Time points as the table allows A No problem SKYAERO will run the simulation based on what the user can provide similarly for the drag mach table Q I do not know the temperature or altitude of the launch site A Search the values on the internet or simply assume a standard value of S5F and 4320 feet for Utah Or assume a Standard Atmosphere value of 59 F at sea level Q How does the Standard Atmosphere pressure compare with that in SKY AERO A Except at sea level the pressure in SKYAERO at any given altitude will not be in agreement to pressure in Standard Atmosphere table so don t panic Q Irun SKYAERO and Excel stops working what am I to do A Some people have encountered problems with SKYAERO and Excel This was mainly due to the operating software in this case Windows Vista SKYAERO has run in Windows XP Vista and 7 satisfactorily but as always Windows Vista seems to conflict in some rare instances If this occurs just do what you can and attempt to run the code directly from visual basic editor Q Can I modify the source code A Sure simply access visual basic editor and add or delete any appropriate content Q Is the program susceptible to float point errors A It was discovered that sometimes Excel had trouble with the increments in time which often resulted in numbers such as OSO0009990000 These errors would make it difficult to locate certain time dependant even
4. March 1949 3 www rsandt com FALSE Plus wind blows away from the launcher 0 0 461538462 0 0923 0 923076923 0 0923 1 384615385 0 0923 1 846 153846 0 0923 2 307692308 0 0923 2 172572771 0 0923 4 615384615 0 0923 5 076923077 0 0923 6 0 0149 Figure 3a Generate Wind Table and Wind Type Input Wind data from WIND CALCULATOR xlsx inher 600 0000 ooo 6s5o ooo0 ooo Figure 3b Wind Table of Input WIND CALCULATOR xlsx generates a vector wind profile using data from two sources Low altitude 150 m 500 ft AGL vector winds are measured as near to launch time as feasible using a tethered pilot balloon TPB The higher altitude synoptic winds are obtained from the online National Weather Service data base for a location near the launch site SKY AERO re resolves the N S and E W profiles into in plane and cross plane profiles Both are developed from the tabular data using linear interpolation North Trajectory North Plane Wind Azimuth Azimuth Wind and Trajectory Azimuth Angles Sign Convention Figure 4 Wind and Trajectory Azimuth Two data sets fed into WIND CALCULATOR xlsx to obtain the N S component wind and E W component wind For more information on this topic you can refer to the materials posted on C Hoult s website Now that the wind data set of two components are obtained SKY AERO will generate a wind profile as a function of altitudes linearl
5. 15 from from E 902 f Flt O from Flt Ops hika SKYAERO SKYAERO haas P 4 598359283 H yY o 2000 00 0 from SKYAERO from SKYAERO in plane wind in plane wind 106 0 a Figure 15 Launcher Settings Input Table 2 139090909 5 071549863 84 9284501 65 05282548 3 4 Using SKYAERO for Other Applications This section will elaborate on SKY AERO s ability to analyze rockets launched from other than a static launcher on the ground This is depends on the creativity and the engineering judgment of the user Some examples for mobile launching are dropping a rocket from an airplane or balloon and launching the rocket from a moving vehicle SKYAERO can also be used for projectiles such as dropping supplies from an airplane When dropping a rocket off an airplane initially the rocket is suspended from a small pre ignition chute to control launch angle and to safely separate rocket from airplane The way to 14 use this feature is very simple Simply type true in first stage on coasting flight and false for the launcher if appropriate type true in first stage coasting on parachute Also input the altitude Vx and V of the rocket at it releases from airplane Typically V will be zero since the airplane will likely be moving horizontally V will be the speed of the airplane unless an initial boost is given to the rocket The altitude must be the MSL value at which the rocket is dropped Singular pertu
6. What does it mean What do I do A Sometimes when an input value is incorrect Excel will display error message Most of the time it is an overflow error or division by zero error It will most likely be a function evaluating a division by zero value or Excel not working fine To fix this problem make sure your inputs are corrected and make sense and then re run Excel 17
7. users encounters is mostly completed and is shown below in Figure 2 The only required input is the launch site surface temperature in degrees Fahrenheit The Farenheit temperature is converted to degrees Rankine when SkyAero begins its calculations The input temperature is actually measured at 2 meters or about 6 ft above the ground level Physical and other Constants Parameter Units Notes ft Polar Earth Radius ft Equatorial Earth Radius ft Polar Tropopause Altitude ft Equatorial Tropopause Altitude ft Ib slug R Gas Consts ant for Air Heat Capacity Ratio Cp Cv for Moist Air 2 lb ft Pressure SL deg ft Tropopause Temperature Lapse Rate Atmospheric Constants Parameter Notes pi 180 Figure 2 Physical and Atmospheric Constants Tables The atmosphere model is very similar to that used in the 1976 US Standard Atmosphere Once a temperature profile has been established in an atmospheric region e g the troposphere then the perfect gas law and the condition of hydrostatic equilibrium are used to obtain the other state variables The troposphere temperature profile uses the standard atmosphere lapse rate but passes through the measured launch temperature Tropopause altitude is found as a function of latitude from data in the Handbook of Geophysics The stratosphere temperature remains constant at its tropopause value The acceleration due to gravity at the geoid 1s modeled with a Potsdam equation
8. Parameters The burn time delay time and separation time are input in the duration column of Phases Events and Durations Input Table The motor burn time is obtained from the powered flight duration time As an example see Figure 11 for this motor the burn time is 7 08 second The delay time for first stage exists when the rocket is air launched It is the duration time between the aircraft release or separation from a lower stage to the ignition of the motor The separation time is the time from the lower stage motor burn out to the separation of the lower Stage Thrust and Drag Data Aero Tech M1939 0 2131 reference area drag ft42 0 2131 reference area drag ft42 0 0000 ROA A 0 0040 0 6907 0 1000 0 2000 B19 y 0 0055 0 4623 0 3000 0 4000 Y Drag data from 0 0167 DRAG COEFFICIENTS 2 xls 2542 8346 for corresponding stage go here for corresponding stage Figure 10 Thrust and Drag Inputs gt 10 The drag tables are to the right in Figure 10 and require three inputs Mach number power on drag coefficient and base pressure coefficient These inputs can be tabulated using Excel file DRAG COEFFICIENT3 2 xlIs from website DRAG COEFFICIENT3 2 xIs contains codes used to estimate sounding rocket zero lift drag coefficients Ideally the aerodynamics group will provide them but more often than not they will only provide power off drag as a function of Mach and the base pressure To obtain the p
9. SKYAERO v 7 6 1 User s Manual By Armando Fuentes Charles Hoult Hien Tran and Michael Tong Mar 02 2014 Table of Contents 1 Zi cema S e ee ne ee a ee eee oS re an eee ee eee 1 ADUT DIOS saat a ee nc ce yee tosses ne ca pence etre ance ve tate E ges et ees eoeeee ee sean osen xed ssaseacyieeeeceaase 2 Del Geophys ING GOOG ciiactetes ste ce cit ce co vecn S TE 2 22 MIM MOLE aa E diese nar E E aes aaa vce E O E E E I AE A O A 3 2 3 Initial and Final ConditionS eessssseenessssssseeeresssssssreresssssssrrrreessssserereesssssereereessssseereeessssseeereeessse 5 2 4 Events Phases and Durations sessssesesssessseressecossserosescossserosescossserosescoseseressscoseserosescosesereseeeoo 6 2 5 Parach te and integration Step SIZES irsinin ai 8 2o D2 21 S E E A 9 Zid IWANSCC WAC OU S eoir E a E E E O E 12 Running and Analyzing the Simulation cccccccsseccccessccecesececeeeccceeescceceuseceseugeceseeneceeseusecesseneess 13 Selig PNN SV D er cadet ee E eee cent EE E N E E A 13 32 Analyzing th RESURS ates o ta teresa nen ceeutateceaaatenot iasa rerun ENEN ENEA NE ESEE SETA e 13 3 3 Using SKYAERO to Adjust Launcher Settings cccccccssseccccseceeeeesececeeseceseeeeceeeeeecetsenesetsenes 14 3 4 Using SKYAERO for Other Applications cccccscccccsssccccessececcenececeeesecessueceeeeeeceeseusecetsugeceesages 14 TE E E eters vos eso a oars tet Sei rye csc sl sew E ee vases nee gs Sty es
10. atitude which will be defined later initial range for whichever launch option is used the initial launch elevation angle and the initial yaw wave number which will be defined later In all cases the initial position vector passes through the launch site You may be wondering what the geodetic latitude and yaw wave number are There are two types of latitudes geocentric and geodetic Below is a definition of both Geocentric latitude defined as the angle between the equatorial plane and a radius vector from the center of the Earth Geodetic latitude defined as the angle between the equatorial plane and a vector normal to the Earth s geoid The yaw wave number refers to a kind of spatial domain frequency that is a consequence of the rocket s moment of inertia and aerodynamic stability This number will usually be provided by the structures or mass properties team Figure 5 shows a lay out of this input table Cartesian coordinate axes are used Subscript x is for the horizontal direction and z for the vertical Inita and Final Conditions Parameters Value i Notes 1898 00 Launch Location Altitude MSL Velocity in x axis at launch ft s Velocity in z axis at launch Quadrant Elevation Angle Not used for first stage after parachute stabilized phase Physical launcher length Not used for first stage after parachute stabilized phase ft Pitch Yaw Wavelength 1898 00 ft Landing Alitude deg
11. deg Launch Latitude rad ft Pitch Yaw Wavenumber at Launch ft sec g at Launch Latitude at MSL 20902678 394f Figure 5 Initial and Final Inputs 2 4 Events Phases and Durations In a time event simulation events are when something important happens Adaptive events depend on how the simulation evolves such as time leaving the launcher rail apogee and impact Many events occur at a scheduled time Examples are ignition and second stage separation from the first stage Whenever the equations of motion change such as when leaving the launcher rail or igniting an upper stage an event must be inserted Also if the rocket s inert mass or drag curve changes such as with parachute deployment an event will be needed Hoult C P The Pitch Yaw Wave Number rev 3 Rocket Science and Engineering Technologies 2009 http rsandt com media The Pitch Yaw Wave Number3 doc A phase is just everything between two adjacent events For example first stage coasting could begin with first stage burnout and end with parachute deployment The phases events input table defines the number of stages of the rocket and whether or not parachutes are present A simple true and false logic is employed to determine which stages will be activated Make sure to select true for coasting and power phase for each stage selected Note that not all events of the stage need to exist However there are some which are essential One example would be the firs
12. e user can also look at the flight path angle acceleration thrust drag Mach number dynamic pressure etc At the far right values at critical events are presented From these columns the user can choose to plot any variables and graphically analyze the results Some important graphs have already been done and are shown in other sheets Hoult C P Finite Inertia Corrections to the Lewis Method Wind Response Aerospace Corp I 0 C A79 5435 44 1979 Hoult C P Launcher Length for Sounding Rocket Point Mass Trajectory Simulations Journal of Spacecraft and Rockets Vol 13 No 12 Dec 1976 pp 760 761 13 3 3 Using SKYAERO to Adjust Launcher Settings SKY AERO has a wind model that can be used to predict the impact point of the rocket This is a very useful tool but incomplete The user must next be able to use the code to adjust the launcher angles to achieve the desired impact point This is done by using the sheet called launcher angles Here the user will run a sequence of simulations and use those values as inputs First run SKYAERO at 90 degrees and obtain the impact point due to each wind component Repeat the procedure but with zero winds and by varying the elevation angle Do as many as you like making sure to go between 82 and 90 degrees The last two inputs are the desired impact locations Fill those out and you will obtain the necessary elevation and azimuth angles needed to accomplish it See Figure
13. k End button Current value Thee Final 3 First Stage Powered Flight on launcher N A 0 0000 10006 0800 0 0000 N A 1898 0000 1898 0000 0 0000 N A Figure 13 Simulation Monitor 12 3 Running and Analyzing the Simulation 3 1 Running SKYAERO Running SKYAERO is very simple After filling out every blue colored cell simply scroll all the way down until you see a rectangle containing two buttons One is for running the simulation and the other for erasing the old values Erasing any old values prior to running a new simulation is recommended California State University Long Beach and Rocket Science and Engineering Technology SkyAero 7 6 1 Clear Current Solution Data Written By Charley Hoult Armando Fuentes Michael Tong Hien Tran Figure 14 Simulation Controls 3 2 Analyzing the Results The results obtained are stored in a sheet called Solution Here the user will be able to see all the necessary output values at different times and to make sure that at each time the rocket is in the right phase The values shown are the state vector elements as a function of time after liftoff TALO Vertical velocity inertial horizontal velocity relative horizontal velocity range mass and altitude Other results include the initial wind speed followed by a correction factor and then the actual simulated speed In other words the simulated speed is the true wind speed after applying a correction factors Th
14. o ewes on basen ene mona en eas 16 1 Getting Started SKY AERO is a point mass time event trajectory and rocket performance simulation SKY AERO is capable of simulating up to 3 stages and both drogue and main chute phases To simplify operation of the program SKY AERO has been color coded The color usage and their meanings are defined in the following text and Figure 1 Green and Orange filled cells represent the titles headers and symbols Magenta filled cells represent the inherent physics of the problem physical constants etc Gray filled cells provide guidance to the users on how to operate SKY AERO Light blue filled cells represent the required user inputs White filled cells are calculated values by SK YAERO based on user inputs and standard physics Natural Constants User Inputs Advisory Material Figure Color coded scheme of SKY AERO Title Symbol Some may wonder why this type of program was created and developed in Microsoft Excel VBA Visual Basic for Applications rather than C Matlab or other programming language With SKYAERO s input and output Microsoft Excel interface users can operate the software with no programming background or knowledge Further this program readily and easily accepts thrust curve data for motor and rocket s drag profile with input tables This program was generated for its simplicity accessibility ease of use and accuracy When running the simulation users may feel tha
15. onds which is pretty accurate except during parachute deployment For this reason the user is given the option of adjusting the times to ensure the simulation runs stably Keep in mind that these shorter time intervals are only needed for a few seconds following parachute deployment Large accelerations are encountered during parachute deployments and if the step size is too large the integration will be unstable Input values are needed for the parachute diameters deployment times and an inflation time constant The time constant is the time required for the parachute to fully deploy It is assumed that the parachute capture areas will follow an exponential behavior One time constant is assumed for all parachutes Users are free to experiment with the values but it is recommended to use the default value General Integration Time Step Time Step for Drogue Phases Time Step for Main Chute Phase Figure 7 Integration Time Steps SKY AERO provides for three parachutes The standard drogue and main are used for recovery But for aircraft and balloon launches a separate drogue is initially used to ensure the launch aircraft is at a safe distance away and the rocket 1s pointing vertically prior to stage ignition Parachute Main Chute Deployment Time Drogue Chute Deployment Time Pre ignition Chute Deployment Time Main Chute Diameter Drogue Chute Diameter Pre ignition Phase Drogue Chute Diameter Pre ignition Phase Chute Deployment Time
16. ower on values simply work backwards using the equations in the Power of Cd column as shows below Cd F Cdon t CP hase Ai ozzle Sref on All this comes about due to the way thrust and drag are defined The pressure area integral is book kept under thrust during burning but is considered part of drag while coasting It s just subtraction addition and some division Immediately below the thrust table there are three cells These are the exit area of the engine nozzle and total impulse and vacuum Isp The user must provide the exit area thr ustcu ive Org 3 AeroTech M1939 Manufacturer Entered Last Updated Mfr Designation Brand Name Common Name Motor Type Diameter Length Total Weight Prop Weight Cert Org Cert Designation Cert Date Average Thrust Maximum Thrust Total impulse Burn Time Isp Case Info Propellant Info Data Sheet Don t like the units Login to set your preferences AeroTech May 25 2006 Sep 18 2012 M1i939W M1i939W M1939 reload 98 0mm 73 2cm 8988g 5719g Tripoli Rocketry Association Inc N1691 2 N 1939 0N 2429 7N 10481 5Ns 6 2s 187s RMS 98 10240 White Lightning link Simulator Files Format Source Updated RockSim user Jun 25 2008 ALT4 lt cert May 30 2006 RASP cert May 30 2006 CompuRoc cert May 30 2006 My Stuff Contributor John Coker John Coker John Coker John Coker Max Thrust N 2 228 7
17. rbations are used at ignition This is done by assuming a small launch rail length 3 inches or so and calculating a simulation launcher length based on the pitch yaw wave number This procedure will fix the flight angle of the rocket until it has enough vertical acceleration and speed to move upwards If this is not done the velocity in the vertical direction will be negative after launching and the new flight angle values will also be negative meaning the rocket will head into the ground This phenomenon is due to the point mass assumption and which cannot simulate the rotational effects of the vehicle To get accurate results the user must use the correct pitch yaw wave number which will reflect the rocket deployment altitude as a function of density Another use for this feature is that of a rocket being launched while suspended from a balloon This has in fact been done many times starting with the Rockoon project in the early 1960s The simulation would simply use a very high launch altitude think Mt Everest and a zero length maybe 3 inches physical launcher rail length The singular perturbation additional rail length that s already in the code will keep things going ok as when launching while descending from a parachute These are two examples of some options that SKY AERO can simulate The analyst must keep in mind the limitations and advantages of the code and as such apply some sound engineering judgment to the results obtained
18. t stage powered flight is needed for a two stage rocket but the first stage coasting flight can be omitted if the rocket goes straight to second stage ignition from first stage burnout For more information user needs to look up the document Events and Phase rev 3 on website From the table in Figure 6 after inputting the launch logic the user will input the duration times between two phases The user can observe the start time and the end time of each event and check if the launch sequence is correct Note that the final phase which will be terminated by impact with the ground should be given an input duration of 9999 0 seconds The actual impact will occur much earlier but this ensures that the simulation run does not stop itself prior to impact Hoult C P Events and Phases rev 3 Rocket Science and Engineering Technologies 2013 http rsandt com media Events_and_Phases rev3 doc Phases Events and Durations Input Table Event Phase loge Duration sec FALSE 1 0000 Burn Time FALSE 10 0000 FALSE PO FALSE PO FALSE PO O FALSE PO eee eee FALSE o FALSE GO Figure 6 Events Phases and Durations Input Table 2 5 Parachute and integration step sizes SKY AERO uses a fourth order Runge Kutta numerical integrator Below the events table the user will encounter parachute inputs and time step inputs The default delta t dt or time step for the flight 1s 05 sec
19. t the simulation is taking longer than expected This is normal Visual Basic calculates slower than other programming languages As a rule of thumb for this program if the simulation lasts more than 10 minutes it should be aborted Unfortunately once the run begins there is no way to stop it through the standard Cabular interface However the program can be stopped directly from the source code using standard computer operation techniques alt break or Esc key The other alternative is to start the task manager ctrl alt delete and shut down MS Excel On average simulations take less than 5 minutes to compute depending on step sizes number of stages employed and the computer s overall capable performance Before starting any work the users must enable Macros the default setting has Macros disabled If macros are disabled follow the instructions provided with MS Excel and enable them To access Excel s Visual Basic programming tools you will need to enable and select the Developer s tab 2 Input Tables Prior to running SKY AERO the users must input fill in all tables that are applicable their problem Failure to fill in the tables properly may result in a degradation in accuracy of the results or an error message The number of tables required to be filled out depends on the number of stages required for the simulation Note that SKY AERO uses English units exclusively 2 1 Geophysics and Geodesy The first table the
20. ts The best solution is to round the values down to whatever accuracy the user wants This was done for the time vector and it satisfactorily fixed the problem Q How do I compute the pitch yaw wave number and why does it matter A Go onto rsandt com website select reports and go to Pitch Yaw Wave Number section or search for it ctrl f It s important to an accurate simulation when the rocket is moving slowly right after ignition The errors in the instantaneous head into the relative wind may be approximately corrected with singular perturbation solutions whose independent variable uses the Pitch Yaw Wave Number Q How do I find the burn time A Go to the thrust time table or graph in Figure I1 and lookup the time when thrust goes to zero Q What are the requirements to run SKY AERO A The requirements are the computer with minimum Excel 2003 the understanding of a rocket s flight the creativity and the engineering judgment Q What are other tools need for SKY AERO Can SKY AERO be used without them A The two tools are WIND CALCULATOR xlsx and DRAG COEFFICIENT3 2 xls The can be found on rsandt com SKYAERO can be run without the above tools with the user provide their own wind profile and drag profile Q How can I make sure the solutions are valid A First the user needs to run a validation with a simple test case This test case can be from a published data or a conducted flight test 16 Q I encountered an error
21. using latitude as its independent variable Corrections for higher altitudes are based on an inverse square law The shape of the earth is considered to be an ellipsoid of revolution again using latitude as the independent variable 2 2 Wind Model Unlike many trajectory simulations SKY AERO has the capability to account for wind The wind model is based on Lewis method which assumes the rocket instantly heads into the relative wind Begin by clearing any old wind data from an earlier run Then if a wind response is needed press Generate Wind Profile Values obtained by WIND CALCULATOR xlsx can be input into SKYAERO WIND CALCULATOR xIsx can be found on Rocket Science and Engineering Technologies website gt WIND CALCULATOR x sx generates two sets of data one for the North South N S component of the wind vector and one for the East West E W component as shown in Figure 3b The user simply types those values into the cells of the table of Figure 3b The program calculates and populates the table of Figure 3a The user also needs to know that he she will need to run the program twice once for in plane wind and again for cross wind for a complete simulation Adolph S Jursa Scientific Editor Handbook of Geophysics and the Space Environment 3rd Edition United States Air Force 1985 Lewis J V The Effect of Wind and Rotation of the Earth on Unguided Rockets Ballistic Research Laboratories Report No 685 Aberdeen
22. y interpolating the wind data obtained To use all the user needs to do is type true in plane false cross wind or none no wind A linear interpolation curve is the straight line between two data points Ideally the more data points we obtained in the field the better the accuracy of the wind profile is To generate the table simply use the buttons in Figure 3 Now that the user knows how to use the tables it is important to briefly describe the use of the in plane wind or cross wind component The wind model is used to predict the landing location of the rocket in the presence of winds SKYAERO has the ability to account for desired landing location by providing elevation and azimuth rocket launch angles In order to achieve this the wind vector is broken into two constituents namely the in plane wind and cross wind directions with respect to the desired trajectory plane and an impact point due to each wind component is calculated A trigonometric calculation is carried out to determine the necessary launch angles to land at a desired location 2 3 Initial and Final Conditions The initial and final conditions table require the user to input values for initial conditions including launch site data and final goals The launcher can be either static or mobile An example of mobile launch would be a rocket being dropped off from an airplane at some designated altitude The inputs are the altitude at the launch site velocity geodetic l
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