This attribute allows you to select the Central Body used in defining an MCS segment.
Astrogator <Satellite Object Path> SetValue <Astrogator Object Path>.CentralBody {Central Body}
You can select any Central Body; the default Central Body of any Launch segment is the Earth. When selecting a Central Body, make certain that the name is copied exactly. For names with two or more words, use underscores instead of spaces or enclose the words of the name in quotation marks.
Astrogator */Satellite/Satellite1 SetValue MainSequence.SegmentList.Launch.CentralBody Mars
STK Programming Interface 11.0.1