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 machine "Space Shuttle" was produced by Zaccaria and a 1984 pinball machine "Space Shuttle: Pinball Adventure" was produced by Williams and features a plastic Space Shuttle model among other artwork of astronauts on the play field. The Space Shuttle also appears in a number of flight simulator and space flight simulator games such as "Microsoft Space Simulator", "Orbiter", "FlightGear", "X-Plane" and Space Shuttle Mission 2007. Several Transformers toys were modeled after the Space Shuttle. The U.S. Postal Service has released several postage issues that depict the Space Shuttle. The first such stamps were issued in 1981, and are on display