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 Pathfinder cost of US$1 million and hired Teledyne Brown Engineering to refurbish it to more closely resemble an actual Space Shuttle. It was named "Pathfinder" and displayed at the Great Space Shuttle Exposition in Tokyo from June 1983 to August 1984. After the exhibit, "Pathfinder" returned to the United States. The U.S. Space & Rocket Center in Huntsville, Alabama designed the display and built a stand. NASA provided MPTA-ET and two filament-wound Solid Rocket Booster casings, which had been designed for polar-orbit launches from Vandenberg Air Force Base. On February 16, 1988, NASA shipped MPTA-ET, a external tank, which had been