The AERCam Sprint free-flyer is a -inch-diameter (), 35-pound (16 kg) sphere that contains two television cameras, an avionics system and 12 small nitrogen gas-powered thrusters. The sphere, which looks like an oversized soccer ball, was released by Mission Specialist Winston E. Scott during the STS-87 spacewalk and flew freely in the forward cargo bay for about 30 minutes. The free-flyer was remotely controlled by Pilot Steven W. Lindsey from the Shuttle's aft flight deck using a hand controller, two laptop computers and a window-mounted antenna. The AERCam is designed to fly very slowly at a rate of less than one-quarter of a foot per second. Remote control of the AERCam is performed through two-way UHF radio communications, with data regarding the status of the free-flyer's systems tran