A moon's orbital elements are relative to its planet, a planet's to its
star — same as every real-world source publishes them (nobody quotes the
Moon's orbit star-relative). Absolute position is the sum of every
ancestor's own position at the same time, walking up the parent chain —
so a station orbiting a planet automatically inherits that planet's
motion, with no separate bookkeeping needed. The star itself (orbit:
null) is the base case, sitting at the system origin.
A moon's orbital elements are relative to its planet, a planet's to its star — same as every real-world source publishes them (nobody quotes the Moon's orbit star-relative). Absolute position is the sum of every ancestor's own position at the same time, walking up the parent chain — so a station orbiting a planet automatically inherits that planet's motion, with no separate bookkeeping needed. The star itself (orbit: null) is the base case, sitting at the system origin.