Preliminary spacecraft pointing requirements error budgets for the space interferometry mission

Preliminary error budgets for the pointing knowledge, control, and stability of the SIM spacecraft are constructed using the specifications of commercial off-the-shelf attitude determination sensors, attitude control actuators, and other spacecraft capabilities that had been demonstrated in past missions. Results obtained indicate that we can meet all the presently known spacecraft pointing requirements. A large number of derived requirements are generated from this study. Examples are specifications on attitude determination sensors, attitude control actuators, minimum settling time after a rest-to-rest spacecraft slew, etc. Since the SLM spacecraft design is expected to evolve with time, pointing requirements stated in this study are likely to change with it. New pointing requirements might also be generated. As such, preliminary error budgets constructed in this study must be revised/updated to reflect the changing spacecraft design and requirements