SHUTTLES AND STATIONS
The space race is over, replaced by a spirit of cooperation where expertise is shared.
With the Moon race won, NASA began work on a new type of space vehicle that could be launched conventionally via rockets, but would also be reusable. On 12 April 1981, the space shuttle Columbia rocketed off the launch pad at Cape Canaveral, piloted by astronauts John Young and Robert Crippen. After a 54-hour test flight, it glided safely back to Earth.
The shuttle has three components: the orbiter, the external tank, and the solid rocket boosters. The orbiter is the distinctive, delta-wing vehicle that carries the payload into orbit. Its underside is covered with 23,000 tiles that protect it from burning up during reentry. The payload bay, at the center of the orbiter, is large enough to hold a passenger bus. The external tank fuels the shuttle engines during launch and burns up in the atmosphere, while the two solid rocket boosters that help propel the shuttle off Earth's surface are ejected prior to orbit. These parachute into the Atlantic Ocean, where they are retrieved and refurbished.
Once in orbit, the shuttle is maneuvered by means of two onboard engines, which are fired at mission's end to slow the orbiter's speed. As the shuttle reenters the atmosphere, aerodynamic controls take over. Moving into a shallow glide path, it makes an unpowered landing.
Today, NASA maintains four space shuttles: Columbia, Discovery, Atlantis, and the newer Endeavor, which was built to replace Challenger, destroyed in a catastrophic explosion. Endeavor can remain in space for 16 days, while the others can make 14-day flights.
The shuttle has racked up many accomplishments. Reusable space laboratories have flown aboard it many times, conducting scientific experiments and astronomical observations. The shuttle's ability to retrieve and deploy satellites from the payload bay with the Remote Manipulator System, a huge mechanical space arm, has made it a valuable asset in the launching, servicing, and repair of satellites of all types. The Hubble Space Telescope has been successfully serviced twice from the shuttle's payload bay. Undoubtedly, the space shuttle will continue to serve science well into the twenty-first century.