SPHERES competiton day

ISS036-E-031698 (13 Aug. 2013) --- In the International Space Station’s Kibo laboratory, NASA astronaut Chris Cassidy, Expedition 36 flight engineer, poses for a photo while conducting a session with a pair of bowling-ball-sized free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES.