Initial high-fidelity, flight-like ground demonstrations of precision formation flying spacecraft are presented. In
these demonstrations, maneuvers required for distributed spacecraft interferometry, such as for the Terrestrial
Planet Finder Interferometer, were performed to near-flight precision. Synchronized formation rotations for
"on-the-fly" observations require the highest precision. For this maneuver, ground demonstration performance
requirements are 5 cm in relative position and 6 arc minutes in attitude. These requirements have been met for
initial demonstrations of formation-keeping and synchronized formation rotations.
The maneuvers were demonstrated in the Formation Control Testbed (FCT). The FCT currently consists
of two, five degree-of-freedom, air bearing-levitated robots. The final sixth degree-of-freedom is being added in
August 2007. Each robot has a suite of flight-like avionics and actuators, including a star tracker, fiber-optic
gyroscopes, reaction wheels, cold-gas thrusters, inter-robot communication, and on-board computers that run
the Formation and Attitude Control System (FACS) software.
The FCT robots and testbed environment are described in detail. Then several initial demonstrations results
are presented, including (i) a sub-millimeter formation sensor, (ii) an algorithm for synchronizing control cycles
across multiple vehicles, (iii) formation keeping, (iv) reactive collision avoidance, and (iv) synchronized formation