Space Shuttle landing at Edwards, the orbiter was flown back to the KSC on the Shuttle Carrier Aircraft, a specially modified Boeing 747. The first orbiter, "Enterprise", was built in 1976, used in Approach and Landing Tests and had no orbital capability. Four fully operational orbiters were initially built: "Columbia", "Challenger", "Discovery", and "Atlantis". Of these, two were lost in mission accidents: "Challenger" in 1986 and "Columbia" in 2003, with a total of fourteen astronauts killed. A fifth operational (and sixth in total) orbiter, "Endeavour", was built in 1991 to replace "Challenger". The Space Shuttle was retired from service upon the conclusion
Space Shuttle for a horizontal landing. Across the Atlantic, European ministers met in Belgium in 1973 to authorize Western Europe's manned orbital project and its main contribution to Space Shuttlethe Spacelab program. Spacelab would provide a multidisciplinary orbital space laboratory and additional space equipment for the Shuttle. The Space Shuttle was the first operational orbital spacecraft designed for reuse. It carried different payloads to low Earth orbit, provided crew rotation and supplies for the International Space Station (ISS), and performed satellite servicing and repair. The orbiter could also recover satellites and other payloads from orbit and return them to Earth. Each Shuttle