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 Pathfinder pan" to drop from a mounting bracket onto the external tank. The damaged area was part of the fiberglass and plywood added to the mockup before its exhibition in Japan. Space Shuttle Pathfinder The Space Shuttle Orbiter "Pathfinder" (unofficial Orbiter Vehicle Designation: OV-098) is a Space Shuttle test simulator made of steel and wood. Constructed by NASA in 1977 as an unnamed facilities test article, it was purchased in the early 1980s by the America-Japan Society, Inc. which had it refurbished, named it, and placed it on display in the Great Space Shuttle Exhibition in Tokyo. The mockup was later