Space Shuttle gliding and landing; it was originally intended to be outfitted for orbital operations after the test program, but it was found more economical to upgrade the structural test article STA-099 into orbiter "Challenger" (OV-099). An additional test article, dubbed "Pathfinder" (OV-098), was built for form and fit tests, and is on display at the Alabama Space and Rocket Center in Huntsville, AL. "Challenger" disintegrated 73 seconds after launch in 1986, and "Endeavour" was built as a replacement from structural spare components. Building "Endeavour" cost about US$1.7 billion. "Columbia" broke apart over Texas during re-entry in 2003. A Space Shuttle launch
Space Shuttle Endeavour 299 days in space. During "Endeavour's" last mission, the Russian spacecraft Soyuz TMA-20 departed from the ISS and paused at a distance of 200 meters. Italian astronaut Paolo Nespoli took a series of photographs and videos of the ISS with "Endeavour" docked. This was the second time a shuttle was photographed docked and the first time since 1996. Commander Mark Kelly was the last astronaut off "Endeavour" after the landing, and the crew stayed on the landing strip to sign autographs and pose for pictures. STS-134 was the penultimate space shuttle mission; STS-135 was added to the schedule in January