CHANTILLY: Discovery on Thursday becomes the first spaceship of the retired US shuttle fleet to enter its permanent home as a museum artifact, marking a solemn end to the 30-year manned spaceflight program.
A few thousand tourists eager to see the shuttle up close streamed into a branch of the Smithsonian National Air and Space Museum outside the US capital, where volunteers handed out miniature American flags.
"I feel like a little kid today," said aerospace engineer Kelly Scroggs, 24, passing a pair of young boys dressed as astronauts as she walked toward the shuttle Enterprise which sat outside the museum awaiting the arrival of Discovery.
A team of about 20 veteran astronauts who flew to space aboard Discovery are to surround the celebrated spacecraft and escort it to the the Steven F. Udvar-Hazy Center in suburban Virginia.
Famous space travelers, including astronaut John Glenn, who was the first American to orbit the Earth in 1962 and later returned to space aboard Discovery in 1998, were to speak.
For several hours on Thursday, the shuttle will rest nose-to-nose on the tarmac with the prototype Enterprise, which has been on display at the same museum but will soon move to New York.
Discovery is the first of the three remaining shuttles that flew in space to enter a museum, where it will serve as a tourist attraction. The others, Endeavour and Atlantis, will follow in the coming months.
Two other shuttles, Challenger and Columbia, were destroyed in accidents. Challenger disintegrated shortly after liftoff in 1986 and Columbia broke apart on re-entry to Earth in 2003. Both disasters killed everyone on board.
The oldest surviving US shuttle, Discovery flew 39 missions to space beginning in 1984.
It drew cheering crowds and some tears from onlookers earlier this week when it toured the skies over Washington one last time, piggybacking atop a Boeing 747 that NASA keeps specifically for transporting the shuttles.
"It will be pretty humbling to see the space shuttle," said Andrew Manning, 15, who came from Connecticut with his Boy Scout group for the Discovery ceremony.
"To think that it was in space, and to think of all the people who risked their lives to go there."
Discovery ended its last mission to space in March 2011, and the return to Earth of Atlantis in July 2011 marked the end of the US shuttle program, leaving Russia as the only nation capable of sending astronauts to space.
Several private companies are competing to be the first to build a space capsule that would replace the US shuttles operated by NASA for three decades.
While a test cargo mission by SpaceX to the International Space Station is planned for April 30, the prospect of US-driven human space flight remains several years away.
To Loretta McHugh, a 35-year-old engineer, the end of the shuttle program is "disappointing."
"I went into engineering because of the space shuttle program. I grew up with the space shuttle since I was five years old," she said, standing near a group of tables where private companies handed out flyers about their aims for returning Americans to space.
"We need to be able to inspire the next generation of engineers and scientists. I know the commercial efforts are taking off literally, but I also think there needs to be a federal program too. Hopefully this is just a short break for us."
A host of dignitaries were on hand to say farewell to Discovery, headlined by John Glenn but also including NASA Administrator Charles Bolden and museum director Jack Dailey.
Other artifacts on display at the museum include the Boeing B-29 Superfortress "Enola Gay," which in 1945 dropped the first atomic weapon used in combat on Hiroshima, Japan.
There is also a supersonic Concorde airliner donated to the museum by France and a single-seat Kugisho MXY7 Ohka (Cherry Blossom) 22 bomber used for attacks on Allied warships, which was captured from Japan in 1945.
Later this year, Endeavour will move from the Kennedy Space Center in Florida to the California Science Center in Los Angeles.
The shuttle Atlantis, also still in Florida, will make just a short hop to a new exhibit at the Kennedy Center's visitor complex.
Enterprise, a prototype shuttle that never flew in space, will head to New York City on April 23 to go on display at the Intrepid Sea, Air and Space Museum. (AFP)