Objective SPHERES (Synchronized Position Hold Engage Re-orient Experimental

International Space Station. The hardware consists of three 23-centimeter diameter, three-kilogram satellites, or “spheres, ” which can control their relative orientations. Each sphere consists of all the subsystems typical of a conventional satellite. The purpose of SPHERES is to provide the Air Force and NASA with a long term, replenishable, and upgradable testbed for validating high risk metrology, control, and autonomy technologies needed for operating distributed satellites as a part of sparse aperture missions such as TechSat21, ST3, TPF, etc. SPHERES draws upon the MODE family of dynamics and control laboratories (STS-40, 42, 48, 62, MIR) by providing a cost-effective laboratory with direct astronaut interaction which exploits the micro-gravity conditions of space. This paper will present the SPHERES objective, design, and hardware status as well as the status of the technologie