This library allows you to examine the gravitational, atmospheric, ephemeris and other properties of the planets, the Sun, the Moon, and other central bodies. You can also create a new central body, such as a comet, asteroid or moon, by duplicating an eligible central body, such as Ceres, and redefining one or more of its parameters.
ComponentBrowser */ SetValue "Central Bodies" {Component} {Attribute} <Value> [{Unit}]
ComponentBrowser */ Duplicate "Central Bodies" {Component} <Duplicate Component Name>
This help details the configuration and parameter attributes for Central Bodies. For more information on Central Bodies, see the Astrogator help for the graphical user interface.
The Central Bodies components are:
| Component | Description |
|---|---|
| Ariel | Moon of Uranus (I) |
| Callisto | Moon of Jupiter (IV) |
| Ceres | Asteroid |
| Charon | Moon of Pluto |
| Deimos | Moon of Mars (II) |
| Dione | Moon of Saturn (IV) |
| Earth | Planet Earth |
| Enceladas | Moon of Saturn (II) |
| Europa | Moon of Jupiter (II) |
| Ganymede | Moon of Jupiter (III) |
| Hyperion | Moon of Saturn (VII) |
| Iapetus | Moon of Saturn (VIII) |
| Io | Moon of Jupiter (I) |
| Jupiter | Planet Jupiter |
| Mars | Planet Mars |
| Mercury | Planet Mercury |
| Mimas | Moon of Saturn (I) |
| Moon | Moon |
| Neptune | Planet Neptune |
| Phobos | Moon of Mars (I) |
| Phoebe | Moon of Saturn (IX) |
| Pluto | Planet Pluto |
| Rhea | Moon of Saturn (V) |
| Saturn | Planet Saturn |
| Sun | Sol |
| Tethys | Moon of Saturn (III) |
| Titan | Moon of Saturn (VI) |
| Titania | Moon of Uranus (III) |
| Triton | Moon of Neptune (I) |
| Uranus | Planet Uranus |
| Venus | Planet Venus |
The sun, planets, and Earth's moon cannot be duplicated; they can only be targeted by the GetValue command. Other moons can be duplicated, and the attributes of those duplicates modified, as described below.
The Duplicate command will nack if entered with the sun, a planet, or Earth's moon. These Central Bodies can not be duplicated.
The following attributes are used to configure the Central Body model:
| Attribute | Values |
|---|---|
| Parent | The parent body of the central body under consideration. You can use any central body name. |
| mu | <Numerical> The gravitational parameter to be used for this gravity model. |
| RegGravity | "Earth_Simple" or the name of the default gravity model for the body, such as, ZonalsToJ4, Icarus2001 |
| Shape | Sphere, "Oblate_Spheroid", or "Triaxial_Ellipsoid" |
| Attitude | RotationCoefficientsFile, or "IAU_1994" |
| Ephemeris | "Analytic_Orbit", "Ephemeris_File", "JPL_DE", "JPL_SPICE", or "Planetary_Ephemeris_File" |
The following attributes are used to define the parameters of the Configuration Attributes:
| RegGravity.Earth_Simple. | Values |
|---|---|
| mu | <Numerical> |
| R | <Numerical> |
| J2 | <Numerical> |
| J3 | <Numerical> |
| J4 | <Numerical> |
| Shape.Sphere. | Values |
|---|---|
| R | <Numerical> |
| Shape.Oblate_Spheroid. | Values |
|---|---|
| Rmin | <Numerical> |
| Rmax | <Numerical> |
| Shape.Triaxial_Ellipsoid. | Values |
|---|---|
| a | <Numerical> |
| b | <Numerical> |
| c | <Numerical> |
| Attitude.RotationCoefficientsFile. | Values |
|---|---|
| Filename | <Path and filename> |
| Attitude.IAU_1994. | Values |
|---|---|
| Epoch | <Numerical> |
| RA | <Numerical> |
| Dec | <Numerical> |
| dRA/dt | <Numerical> |
| dDec/dt | <Numerical> |
| Offset | <Numerical> |
| Rate | <Numerical> |
| Ephemeris.Analytic_Orbit. | Values |
|---|---|
| Epoch | <Numerical> |
| a | <Numerical> |
| da/dt | <Numerical> |
| e | <Numerical> |
| de/dt | <Numerical> |
| i | <Numerical> |
| di/dt | <Numerical> |
| raan | <Numerical> |
| draan/dt | <Numerical> |
| lp | <Numerical> |
| dlp/dt | <Numerical> |
| L | <Numerical> |
| dL/dt | <Numerical> |
| Ephemeris.Ephemeris_File. | Values |
|---|---|
| EphemFileName | <File in scenario directory> |
| Ephemeris.JPL_SPICE. | Values |
|---|---|
| SpiceIdNumber | <Numerical> |
| Ephemeris.Planetary_Ephemeris_File. | Values |
|---|---|
| PlEphemFileName | <File in scenario directory> |
The JPL_DE ephemeris attribute does not have any parameter attributes.
ComponentBrowser */ Duplicate "Central Bodies" Charon "My Charon"
ComponentBrowser */ SetValue "Central Bodies" "My Ganymede" Shape "Triaxial_Ellipsoid"
ComponentBrowser */ SetValue "Central Bodies" "My Ganymede" Ephemeris "JPL_DE"
ComponentBrowser */ SetValue "Central Bodies" "My Ganymede" "Shape.Oblate_Spheroid.Rmin" 6370 km
ComponentBrowser */ SetValue "Central Bodies" "My Ganymede" "Ephemeris.Ephemeris_File.EphemFileName" EphemFile.e
STK Programming Interface 11.0.1