SPHERES-Derived Mars Orbiting Sample Retrieval Testbed (SPHERES MOSR)

We propose to modify the Synchronized Position, Hold, Engage, and Reorient Experimental Satellites (SPHERES) system to serve as an on-orbit testbed for Mars orbiting sample retrieval (MOSR) equipment and techniques for a Mars Sample Return (MSR) mission. The SPHERES system, a novel spacecraft flight testbed developed by Payload Systems Inc. and the MIT Space Systems Laboratory, is currently scheduled for its first mission aboard the International Space Station in 2004 to demonstrate metrology, formation flying, rendezvous/docking, and autonomy algorithms. The innovation proposed here would adapt and extend the SPHERES system for a follow-on mission to ISS to serve as a testbed for MSR autonomous terminal-phase rendezvous and capture technologies ? including guidance algorithms, rendezvous and capture techniques, and capture mechanisms ? as would be involved in the retrieval of a sample lofted into Mars orbit. The autonomous retrieval of the orbiting sample is one of the most technically complex and risky aspects of the MSR mission. The SPHERES MOSR testbed would streamline OS retrieval algorithm and hardware development, and significantly reduce the risk of this critical MSR mission operation. This Phase II effort would result in a flight hardware system implementation ready to enter the Shuttle/ISS payload integration process.