Space shuttle Discovery mounted to a Shuttle Carrier Aircraft at NASA's Kennedy Space Center in Florida.

Space shuttle Discovery, mounted to a Shuttle Carrier Aircraft, slowly rolls along the runway of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The duo is set to begin their 3 1/2 hour ferry flight to the Washington Dulles International Airport in Virginia at about 7 a.m. EDT. Above the two craft is a NASA helicopter covering the departure. Discovery is leaving Kennedy after more than 28 years of service beginning with its arrival on the space coast Nov. 9, 1983. Discovery first launched to space Aug. 30, 1984, on the STS-41D mission. Discovery is the agency's most-flown shuttle with 39 missions, more than 148 million miles and a total of one year in space.

Discovery is set to move to the Smithsonian's National Air and Space Museum Steven F. Udvar-Hazy Center on April 19 where it will be placed on public display. For more information on the SCA, visit http://www.nasa.gov/centers/dryden/news/FactSheets/FS-013-DFRC.html. For more information on shuttle transition and retirement activities, visit http://www.nasa.gov/transition. Photo credit: NASA/Frankie Martin