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 retirement to 2028 or beyond. Until another U.S. crew vehicle is ready, crews will access the ISS exclusively aboard the Russian Soyuz spacecraft. The Soyuz was chosen as the ISS lifeboat during the development of the International Space Station, and has been one of the space taxis used by the international participants to this program. A Soyuz took Expedition 1, which included one U.S. astronaut in the year 2000. Previously the United States and Russia had collaborated on extended the Mir space station with the Shuttle-Mir program in the 1990s. Although the Orion spacecraft is oriented towards deep-space missions such as