period at the Kennedy Space Center. Work began in September 2002 to prepare the vehicle for Return to Flight. The work included scheduled upgrades and additional safety modifications. Decommissioning and display Discovery was decommissioned on March 9, 2011. NASA offered Discovery to the Smithsonian Institution's National Air and Space Museum for public display and preservation, after a month-long decontamination process, as part of the national collection. Discovery replaced in the Smithsonian's display at the Steven F. Udvar-Hazy Center in Virginia. Discovery was transported to Washington Dulles International Airport on April 17, 2012, and was transferred to the Udvar-Hazy on April 19 where a welcome ceremony was held. Afterwards, at around 5:30 pm, Discovery was rolled to its "final wheels stop" in the Udvar Hazy Center. Flights By its last mission, Discovery had flown 149 million miles (238 million km) in 39 missions, completed 5,830 orbits, and spent 365 days in orbit over 27 years. Discovery flew more flights than any other Orbiter Shuttle, including four in 1985 alone. Discovery flew both "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. Flights listing ‡ Longest shuttle mission for Discovery – shortest shuttle mission for Discovery Mission and tribute insignias Flow directors 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 the spacecraft's ground crew while the astronaut flight crews changed for every mission. Each shuttle's Flow Director was supported by a Vehicle Manager for the same spacecraft. Space Shuttle Discovery'''s Flow Directors were: Until 01/1991: John J. "Tip" Talone Jr. (afterwards Flow Director for Endeavour) 01/1991 – 09/1992: John C. "Chris" Fairey 09/1992 – 10/1996: David A. King 10/1996 – 05/2000: W. Scott Cilento 12/2000 – 03/2011: Stephanie S. Stilson Gallery {| class="wikitable" style="text-align:center" |- | | | | | |- |<small>The launch of STS-41-D, Discovery's first mission.</small> |STS-121 launched on July 4, 2006 – the only Shuttle to launch on Independence Day. |STS-119 on the night of March 11, 2009. |Discovery sits atop