Space Shuttle program March 25, 1979, and was first launched on April 12, 1981—the 20th anniversary of Yuri Gagarin's space flight—with a crew of two. "Challenger" (OV-099) was delivered to KSC in July 1982, "Discovery" (OV-103) in November 1983, "Atlantis" (OV-104) in April 1985 and "Endeavour" in May 1991. "Challenger" was originally built and used as a Structural Test Article (STA-099), but was converted to a complete orbiter when this was found to be less expensive than converting "Enterprise" from its Approach and Landing Test configuration into a spaceworthy vehicle. On April 24, 1990, "Discovery" carried the Hubble Space Telescope into space during
Space Shuttle made Space Shuttle thermal protection system tiles available to schools and universities for less than US$25 each. About 7,000 tiles were available on a first-come, first-served basis, limited to one per institution. On April 12, 2011, NASA announced selection of locations for the remaining Shuttle orbiters: In August 2011, the NASA Office of Inspector General (OIG) published a "Review of NASA's Selection of Display Locations for the Space Shuttle Orbiters"; the review had four main findings: The NASA OIG had three recommendations, saying NASA should: In September 2011, the CEO and two board members of Seattle's Museum of Flight met