Orbit Wizard

Top  Previous  Next

The Orbit Wizard is accessible via the Orbit Wizard button at the bottom of the Orbit Page of the Spacecraft Object Editor, and through FreeFlyer script. Using the Orbit Wizard allows you to quickly load orbit state data from a file or create an orbit in one of the following orbit types:

 

Sun-synchronous

Geosynchronous

Molniya

Circular

Interplanetary (Wizard available in FreeFlyer Script only - in the Spacecraft Object Editor, simply change the Spacecraft's Central Body.)

 

With the exception of the Interplanetary Orbit Wizard, the central body for the Orbit Wizard is always the Earth.

 

Mission Plan Wizard: Orbit Type GUI

Mission Plan Wizard: Orbit Type GUI

 

 

Using the Orbit Wizard in FreeFlyer Script


The examples below show use the Orbit Wizard through FreeFlyer script. Each orbit type is configured using a different method of the Spacecraft object.

 

// Set up a 750 km altitude circular orbit

Spacecraft1.OrbitWizardCircularSetup(1, 750);

 

// Set up a geosynchronous orbit

Spacecraft1.OrbitWizardGeoSynchSetup(epochAtEquator, longitudeAtEquator, E, W, TA);

 

// Set up an orbit around Mars

Spacecraft1.OrbitWizardInterplanetarySetup("Mars", epoch, A, E, I, RAAN, W, TA);

 

// Set up a Molniya orbit that dwells in the northern hemisphere

Spacecraft1.OrbitWizardMolniyaSetup(epochAtApogee, longitudeAtApogee, 1);

 

// Set up a sunsynchronous orbit with an 8000 km semi-major axis and a

// local ascending node crossing time of 18:30:00

Spacecraft1.OrbitWizardSunSyncSetup(1, epoch, E, "18:30:00", 8000);

 

 

Loading Orbit States from External Files


Ephemeris or NORAD TLE files can be used to initialize a spacecraft's state in the orbit wizard by clicking the "Load State from File" option in the Orbit Type drop down box, and then browsing for the file. The spacecraft state will be initialized using a single user-specified vector or TLE.

 

To load a single state from an ephemeris or TLE from FreeFlyer script, the Spacecraft.LoadNoradTLE and Ephemeris.GetVector methods can be used:

 

// Loads the first state in the TLE file

Spacecraft1.LoadNoradTLE("filename.tle", 0);

 

// Loads the first state in the ephemeris file

Array stateArray;

Ephemeris Ephemeris1;

 

Ephemeris1.LoadEphemeris("filename.FFephem");

 

Ephemeris1.GetVector(0, stateArray);

 

Spacecraft1.Position = {stateArray[0], stateArray[1], stateArray[2]};

Spacecraft1.Velocity = {stateArray[3], stateArray[4], stateArray[5]};

 

See Ephemerides and AHF for more information on ephemeris files, or the Spacecraft Propagation guide for more information on modeling spacecraft motion.

 

 

See Also


Ephemerides and AHF

Spacecraft Propagation