Shortly after sunrise Tuesday, the powered-down space shuttle Discovery began its ride into the sunset atop a Boeing 747.
NASA's longest-serving shuttle, shown above Florida's Kennedy Space Center, was carried north to Virginia's Dulles International Airport, pausing for a victory lap over Washington, D.C. On Thursday Discovery will roll to its final resting place, a Smithsonian Institution facility near the airport.
Even before NASA's final space shuttle mission—an Atlantis expedition last July—workers had begun making Discovery safe for the National Air and Space Museum's Steven F. Udvar-Hazy Center, draining toxic fluids, disabling flammable fuel cells, and removing other dangers.
In its time Discovery marked a series of space milestones. The shuttle was the first to dock with Russia's Mir space station, carried NASA's first African-American mission commander as well as the first woman to pilot a spacecraft—and executed the first "return to flight" missions after the Challenger disaster.
—With reporting by Ker Than
Photograph courtesy Glenn Benson, NASA
So Long, Space Coast
Piggybacking away from the Kennedy Space Center's 50-story-tall Vehicle Assembly Building Tuesday, Discovery departs Florida's Space Coast one last time.
Named after a series of historic exploration ships, Discovery made its maiden voyage into space on August 30, 1984. Since then it's logged the most flight hours of any space shuttle in NASA's fleet, flying 39 missions and spending 365 days in space.
Over the years the spaceship has earned a reputation among historians and shuttle enthusiasts as the "dependable older sibling" of the shuttle fleet.
"Its legacy is that it is the reliable workhorse," Robert Pearlman, editor of the space history and artifacts website collectSPACE.com, told National Geographic News in 2010.
Discovery shoots over the White House Tuesday en route to Dulles International Airport. For security reasons, officials did not list the exact flight path for the space shuttle and its carrier, though NASA and the Smithsonian Institution encouraged spectators to be on the lookout from the National Mall and other key shuttle-spotting points.
The Boeing 747 ferrying space shuttle Discovery departs NASA's Kennedy Space Center at about 7 a.m. ET on Tuesday.
Space shuttles were never meant to fly like conventional aircraft, instead being boosted into space with the help of detachable engines and fuel tanks. Returning to Earth, the shuttles performed essentially as giant gliders.
Visitors to the U.S. Capitol watch space shuttle Discovery's final voyage as it soars above Washington on Tuesday.
Discovery was no stranger to two Capitol regulars. In 1985 it carried Utah senator Jake Garn into space, a first for a U.S. congressperson. And in 1998 Discovery blasted off with 77-year-old former Ohio Senator John Glenn—the oldest person to fly in space.
Wearing a space shuttle costume, four-year-old Alex Mendez, of Sterling, Virginia, awaits the arrival of the space shuttle Discovery at the National Air and Space Museum's Steven F. Udvar-Hazy Center on Tuesday.
It will be two days before Discovery arrives, to great fanfare, at its final home, the center's James S. McDonnell Space Hangar. There, Discovery will displace the space shuttle Enterprise, which never made it out of Earth orbit.
A boy sports an astronaut costume at the National Air and Space Museum's Udvar-Hazy Center on Tuesday in Chantilly, Virginia. Hundreds of people gathered at the museum to watch the arrival of the space shuttle Discovery, which was tethered to the back of a modified 747 jumbo jet.
"At the Udvar-Hazy Center," museum director John Dailey said in a statement, "Discovery will be seen by millions of people in the coming years, especially children, who will become the next generation of scientists, engineers, researchers and explorers.