The MIT Space Systems Laboratory and Payload Systems Inc. has developed the SPHERES testbed for NASA and DARPA as a risk-tolerant medium for the development and maturation of spacecraft formation flight and docking algorithms. The testbed, which is designed to operate both onboard the International Space Station and on the ground, provides researchers with a unique long-term, replenishable, and upgradeable platform for the validation of high-risk control and autonomy technologies critical to the operation of distributed spacecraft missions such as the proposed formation flying interferometer version of Terrestrial Planet Finder (TPF). In November 2003, a subset of the key TPF-like maneuvers has been performed onboard NASA's KC-135 microgravity facility, followed by 2-D demonstrations of two and three spacecraft maneuvers at the Marshall Space Flight Center (MSFC) in June 2004. Due to the short experiment duration, only elements of a TPF lost in space maneuver were implemented and validated. The longer experiment time at the MSFC flat-floor facility allows more elaborate maneuvers such as array spin-up/down, array resizing and array rotation be tested but in a less representative environment. The results obtained from these experiments are presented together with the basic estimator and control building blocks used in these experiments.