Well, this is my first post--hopefully I'm posting in the correct forum... I'm developing a space simulator computer application in which a rigid body's motion is calculated using its linear momentum and rotational momentum. I'm simulating multiple bodies attached together (for example, a single space craft with missiles attached or a freighter with cargo attached), and I want to be able to release the attached objects and update the mass, center of mass, moment of inertia for all axes, linear momentum, etc. of the remaining group of objects. The only thing I'm having trouble with is understanding what would happen to the rotational momentum when one of the objects is released from a rotating group (imagine the freighter dropping its cargo in an emergency). My guess is that the group will lose rotational momentum proportionally to how much mass was dropped. I can use the parallel axis theorem to calculate the change in inertia, but is there a similar theorem or rule which I can use to determine the change in rotational momentum?