Description
Name of the body that defines the origin of the Spacecraft's position and velocity. This can be a user-defined CelestialObject or one of the following pre-defined bodies:
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Moon
Sun
In order to translate the origin of a Spacecraft's state to a different central body, simply change the Spacecraft.CentralBody property.
Timing Precision Mode
This page describes functionality in nanosecond timing precision mode.
Click here to see the documentation for this object in millisecond timing precision mode.
Attributes
Type: |
string |
Access: |
read/write |
Default Value: |
"Earth" |
Syntax
myString1 = mySpacecraft1.CentralBody;
mySpacecraft1.CentralBody = myString1; |
In order to translate the origin of a Spacecraft’s state to a different central body, you can simply change the Spacecraft.CentralBody property. You can do this at any point in your Mission Plan, and FreeFlyer will automatically convert both position and velocity. The following example shows how to convert a Spacecraft's state from Earth-centered to Moon-centered.
Output:
This can be used any time you want to reference a Spacecraft’s state to another built-in celestial body or any custom user-defined CelestialObject.
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If you want to examine a Spacecraft's state with respect to another celestial body without changing its central body, you can also calculate this using simple vector addition. The following example shows how to calculate a Spacecraft's position and velocity with respect to the Earth when the Spacecraft's central body is the Moon.
This adds the Spacecraft’s position and velocity (in the MJ2000 coordinate frame, with the Moon as the central body) to the Moon’s position and velocity with respect to the Earth (also in the MJ2000 frame).
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See also
Coverage and Contact Analysis Guide