Although control of the flight switches to the Mission Control Center in Houston as the Space Shuttle clears the tower, the responsibilities of the launch operations team are far from over.
At approximately two minutes after the Space Shuttle lifts off from the launch pad, the twin Solid Rocket Boosters have expended their fuel. The boosters separate from the Orbiter and begin their long tumble back to Earth where two retrieval ships are waiting.
NASAΓÇÖs two retrieval ships that perform the SRB recovery -- Freedom Star and Liberty Star -- are uniquely designed and constructed for the task. The propulsion systems allows divers to work near the ship during operations at a greatly reduced risk and protect the endangered manatee population that inhabits regions of the Banana River where the ships are based.
Each ship retrieves one booster. First, the main parachutes are brought on board with their shroud lines wound onto reels on the shipΓÇÖs deck. Then the 5,000-pound frustum is lifted from the water using the shipΓÇÖs power block and deck crane.
With the chutes and frustum recovered, attention turns to the SRB. First the dive team installs a Diver-Operated Plug (DOP) in the nozzle of the booster. Air is pumped into the booster through the DOP, displacing water within the casing. As the process continues, the booster rises in the water until it becomes top-heavy. It falls horizontally, like a log in the water. Air pumping continues until all water is expelled from the empty casing. The booster is secured to the recovery ship with a towline and the trip back to NASAΓÇÖs Hangar AF on Cape Canaveral Air Station begins.
Throughout the mission, recovery crews are on site at designated contingency landing strips throughout the world to support an emergency landing and ensure the safety of the vehicle before the astronauts egress. The Shuttle can make an emergency landing, if necessary, at Ben Guerir Air Base, Morocco; Moron Air Base and Zaragosa Air Base, Spain; and Yundum International Airport, Banjul, The Gambia. The U.S. sites are at Edwards Air Force Base, California, and White Sands, New Mexico.
KSCΓÇÖs Shuttle Landing Facility (SLF was specially designed for returning Space Shuttle orbiters. The runway is longer and wider than those found in most commercial airports, yet comparable in size to runways designed for research and development facilities.
Although a single landing strip, it is considered two runways, depending on the approach, from either the northwest on Runway 15 or from the southeast on Runway 33.
The orbiter differs in at least one major aspect from conventional aircraft; it is unpowered during re-entry and landing so its high-speed glide must be perfectly executed the first time ΓÇö there is no go-around capability. The orbiter touchdown speed is 213 to 226 miles per hour.
Although on call during an entire mission in case of an earlier-than-scheduled landing, the Orbiter Convoy normally begins recovery operations in earnest about two hours before the orbiter is scheduled to land.
The convoy consists of about 25 specially designed vehicles or units and a team of about 150 trained personnel who assist the crew in leaving the orbiter, "safe" the orbiter, prepare it for towing, and tow the vehicle to the Orbiter Processing Facility where processing begins for its next mission.
