Synchronized Formation Rotation and Attitude Control of Multiple Free-Flying

In the observation slewing of long base-line'interferometers formed by multiple b flying spacecraft in formation, it is required to rotate the entire formation about a given axis, and to synchronize individual spacecraft rotation with formation rotation. Using a particle model for spacecraft formation dynamics, and a rigid-body model for spacecraft attitude dynamics, control laws are derived for this mode of operation in the absence of &r*dig gravitational field and disturbances. A simplified control law suitable for implementation is also obtained. It is shown that under mild conditions, the formation alignment error decays to zero exponentially with time. Computer simulation studies are made for a free-flying spacecraft triad in a triangular formation. The results show that the developed control laws are effective in synchronized formation rotation