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Interface/Functional Spec


A celestial body model


The CelestialBody resource is a model of a celestial body containing settings for the physical properties, as well as the model for the orbital motion and orientation.  GMAT contains built-in models for the Sun, the 8 planets, Earth's moon, and Pluto.  You can create a custom CelestialBody resource to model a planet, asteroid, comet, or moon. 
See Also:  SolarSystem, Barycenter, LibrationPoint, CoordinateSystem.


See the User Interface Spec spreadsheet for reference information for fields.  This section is usually empty other than the hyperlink.


The CelestialBody GUI has three tabs that allow you to set the physical properties, orbital properties, and the orientation model.  For a built-in CelestialBody, the Orbit and Orientation tabs are largely inactive.   See the discussion below for behavior of each panel.  

The CelestialBody Properties tab is shown above.  GMAT models all bodies as a spherical ellipsoid and you can set the Equatorial Radius, Flattening, and gravitation parameter (Mu) on this dialog, as well as the texture map used in graphical displays.





The CelestialBody Orbit tab.








For Developer and GUI Tester:  If we add DE421 as Lunar RotatationDataSource, then we will need to make that field active in the panel above. 




Overview of Celestial Body Orientation Model
GMAT asdf.OrientationEpoch = 21545;
GMAT asdf.SpinAxisRAConstant = 0;
GMAT asdf.SpinAxisRARate = -0.641;
GMAT asdf.SpinAxisDECConstant = 90;
GMAT asdf.SpinAxisDECRate = -0.5570000000000001;
GMAT asdf.RotationConstant = 190.147;
GMAT asdf.RotationRate = 360.9856235;
Physical Properties
GMAT asdf.Flattening = 0.0033527;
GMAT asdf.EquatorialRadius = 6378.1363;
GMAT asdf.Mu = 398600.4415; 
Orbit Ephemeridies
GMAT asdf.NAIFId = -123456789;
GMAT Earth.SourceFilename = '../data/planetary_ephem/de/leDE1941.405';
Unique fields Earth and Moon
GMAT Earth.RotationDataSource = 'FK5IAU1980';
GMAT Earth.NutationUpdateInterval = 60;
Use Custom Texture Map
GMAT Earth.TextureMapFileName = '../data/graphics/texture/ModifiedBlueMarble.jpg';
GMAT asdf.PosVelSource = 'SPICE';
GMAT asdf.CentralBody = 'Earth';
GMAT asdf.RotationDataSource = 'IAUSimplified';




Configure a CelestialBody to model the asteroid RQ236.




Configure a CelestialBody to model the Mars’ moon Phobos.





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