Marshall Space Flight Center of the launch vehicle. Finally, on April 24, 1990, on Mission STS-31, Shuttle "Discovery" launched the Hubble telescope successfully into its planned orbit. Almost immediately it was realized that the optical performance was not as expected; analysis of the flawed images showed that the primary mirror had been ground to the wrong shape, resulting in spherical aberration. Fortunately, the Hubble telescope had been designed to allow in-space maintenance, and in December 1993, mission STS-61 carried astronauts to the Hubble to make corrections and change some components. A second repair mission, STS-82, was made in February 1997, and a third, STS-103,
Space Shuttle Discovery alone. "Discovery" flew all three "return to flight" missions after the "Challenger" and "Columbia" disasters: STS-26 in 1988, STS-114 in 2005, and STS-121 in 2006. "Discovery" flew the ante-penultimate mission of the Space Shuttle program, STS-133, having launched on February 24, 2011. "Endeavour" flew STS-134 and "Atlantis" performed STS-135, NASA's last Space Shuttle mission. On February 24, 2011, Space Shuttle "Discovery" launched from Kennedy Space Center's Launch Complex 39-A to begin its final orbital flight. The Flow Director was responsible for the overall preparation of the shuttle for launch and processing it after landing, and remained permanently assigned to head