English: Seen carrying a spent solid rocket booster (SRB) from the STS-87 launch on Nov. 19 is the solid rocket booster recovery ship Liberty Star as it reenters the Hangar AF area at Cape Canaveral Air Station. Hangar AF is a building originally used for Project Mercury, the first U.S. manned space program. The SRBs are the largest solid propellant motors ever flown and the first designed for reuse. After a Shuttle is launched, the SRBs are jettisoned at two minutes, seven seconds into the flight. At six minutes and 44 seconds after liftoff, the spent SRBs, weighing about 165,000 lb., have slowed their descent speed to about 62 mph and splashdown takes place in a predetermined area. They are retrieved from the Atlantic Ocean by special recovery vessels and returned for refurbishment and eventual reuse on future Shuttle flights. Once at Hangar AF, the SRBs are unloaded onto a hoisting slip and mobile gantry cranes lift them onto tracked dollies where they are safed and undergo their first washing.