Space shuttle Endeavour is towed to the Kennedy Space Center landing facility in Cape Canaveral, Fla., on Friday. John Raoux/AP Photo hide caption

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The space shuttle Discovery is loaded onto the back of a modified 747 at Kennedy Space Center on April 15. The plane will ferry the shuttle to Washington, D.C., on April 17, where it will be permanently installed at the Smithsonian National Air and Space Museum. Kim Shiflett/NASA hide caption

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Every space shuttle mission had its own mission emblem, designed and worn by the crews. Centered in this photo are the embroidered patches for the first and last missions, STS-1 and STS-135. The STS-1 emblem is a rare version, produced only for the astronauts and NASA employees. The souvenir edition was slightly different. collectSPACE.com hide caption

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Atlantis lifts off from Kennedy Space Center on its final flight on July 8. There are plans for a next-generation space vehicle, but some space experts aren't sure if the vehicle will ever be completed. Tony Gray and Tom Farrar/NASA hide caption

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A large section of Discovery's nose, called the forward reaction control system, which helped steer the shuttle while in orbit, was removed in March. The spacecraft will be cleaned and detoxified before being put on display in museums. Jim Grossmann/NASA hide caption

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The International Space Station as seen from the space shuttle Atlantis after it undocked from the outpost in November 2009. Despite an end to the space shuttle program, NASA says scientific work is just getting into full gear on the space station. NASA hide caption

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A worker tests components on a model of the space shuttle before wind tunnel testing. NASA hide caption

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The San Andres Mountains and pieces of construction equipment are reflected in the glass windows of Spaceport America near Upham, N.M., in May. Despite construction delays and difficult working conditions in a remote area of the desert, state officials say New Mexico is committed to seeing the project succeed. Susan Montoya Bryan/AP hide caption

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Seventh-graders Sophie Maloro (left) and Unity Bowling "fly" a mission to Mars, part of a summer program at the MathScience Innovation Center in Richmond, Va. Larry Abramson/NPR hide caption

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The Virgin Galactic VSS Enterprise spacecraft is seen before its first public landing during the Spaceport America runway dedication ceremony near Las Cruces, N.M., on Oct. 22. Virgin Galactic is one of a handful of private companies that plan to fly paying customers into space. Mark Ralston/AFP/Getty Images hide caption

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Crew members of the International Space Station — (from left) U.S. astronaut Ron Garan and Russian cosmonauts Alexander Samokutyaev and Andrei Borisenko — prepare to enter a Soyuz simulator outside Moscow on March 30. With the space shuttle program out of commission, the Russian Soyuz vehicle will be the only way for Americans to reach space. Dimitry Kostyukov/AFP/Getty Images hide caption

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Food packets containing the astronauts' "all-American meal," including (clockwise from top left) corn, chicken, brisket, and beans, along with a lemonade, at right. Devin Boldt/NASA - JSC hide caption

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Unidentified Fashion Object: A 1963 rendering shows the design for Biff's Coffee Shop in Oakland, Calif. "It almost looked like a flying saucer," says Victor Newlove of Armet Davis Newlove Architects. "It looks like it's about ready to lift off." Armet & Davis Architects hide caption

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Ellen Ochoa (left), the first Hispanic female astronaut, and Major Eileen M. Collins, the first woman to be named as a pilot candidate, begin their first day of candidate training at NASA in Houston, Texas, on July 16, 1990. AP hide caption

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In the future, people will be carried into space by private-sector projects like the Virgin Galactic VSS Enterprise, says former astronaut Jeffrey Hoffman. Here, the Enterprise sits behind Virgin boss Richard Branson, left, and New Mexico Gov. Bill Richardson. Mark Ralston/AFP/Getty Images hide caption

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Artifacts from the space shuttle program, and the final mission by Atlantis, are destined for the Smithsonian Air and Space Museum. Here, Atlantis blasts off from Kennedy Space Center for its last mission. Chip Somodevilla/Getty Images hide caption

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