Photos: Space shuttle launches 25 years ago

It was a "happening" in 1981. After 36 orbits and 55 hours in space, the crew landed the Columbia at Edwards Air Force Base in California. The first flight was primarily used to test systems and pave the way for more shuttle flights--114 and still counting.

Throughout the years, the shuttles have been rebuilt and upgraded many times. Here are astronauts John Young and Bob Crippen at one of the original Columbia control panels.

First used for a 2000 mission, a rebuilt glass cockpit, complete with 11 full-color flat-panel screens, replaced the old dials and gizmos. The new LCD displays offer many advantages over the older devices, including better viewing angles, better backup capabilities and less power consumption.

Probably the most spectacular missions of the space shuttle program involved repairing the Hubble Space Telescope. Launched into orbit in 1990, the Hubble was a bust due to a mirror that was out of focus.

A space shuttle rescue team repaired the mirror in 1993 and three other shuttle missions have provided maintenance and repairs. Note the astronauts hanging from the shuttle's arm in this 1999 mission. At the time, it was feared that if the December 1999 repair mission had been delayed, it might have been derailed by the Y2K bug.

The Hubble is currently in need of further repairs but funding for a new space shuttle repair mission looks bleak.

The shuttle program may be best known for its two disasters. In 1986, the shuttle Challenger exploded during its takeoff, and in 2003 the Columbia blew apart upon reentry. Both crews were killed. This photo of the 2003 Columbia crew was processed from film found in the shuttle wreckage.

After many hearings, studies and new safety measures, the space shuttle program went back to business in 2005 with a mission to resupply and change crews at the International space station.

The shuttle cargo bays have carried scientific equipment, satellites, parts and space station supplies.

Despite the increased safety precautions, the 2005 flight of Discovery appeared to be in jeopardy when a piece of foam damaged heat-shield tiles on the underside of the shuttle during takeoff.

NASA scientists discovered that two ceramic coated-fabric gap fillers, which are used to prevent hot gas from seeping into gaps between Discovery's protective tiles, were sticking out about an inch from the shuttle's belly.

Shuttle astronauts have taken numerous space walks to repair satellites, conduct tests and help build the International Space Station. Mission Specialist Steve Robinson dangles in space attached to the arm of the space shuttle on Aug. 3, 2005, as he successfully removes protruding thermal-protection gap fillers from the heat shield of Discovery.

With the Columbia disaster, the aging remaining shuttles and the high cost of the program, the future of space shuttle travel is in jeopardy. The next flights for Discovery and Endeavor are tentatively scheduled for the summer of 2006. NASA, meanwhile, will be building bigger rockets and pointing them toward the moon and, eventually, Mars.