CHANTILLY, Virginia  - Discovery on Thursday will become 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 team of about 20 veteran astronauts who flew to space aboard Discovery will surround the celebrated spacecraft and escort it to a branch of the Smithsonian National Air and Space Museum outside the US capital. 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, are scheduled to speak at the ceremony.

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 Steven F. Udvar-Hazy Center in suburban Virginia 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 and drew cheering crowds and some tears from onlookers earlier this week when it toured the skies over Washington one last time.

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.

In the meantime, museum officials were busily preparing for a host of dignitaries to say farewell to Discovery, headlined by John Glenn but also including NASA Administrator Charles Bolden and museum director Jack Dailey.

Fourteen of the shuttle’s 31 living commanders will be in attendance for the ceremony, which will feature the US Marine Drum and Bugle Corps and is scheduled to begin at 11 am (1500 GMT).

Discovery toured the US capital Washington for nearly an hour on Tuesday, piggybacking atop a Boeing 747 that NASA keeps specifically for transporting shuttles.