The space shuttle Discovery is suspended from a sling held by two cranes after the NASA 747 Shuttle Carrier Aircraft (SCA) was pushed back from underneath at Washington Dulles International Airport, Thursday, April 19, 2012, in Sterling, VA. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

NASA Orbiter Transition & Retirement team member Tom Goebel monitors the installation of "rain covers" over space shuttle Enterprise’s vent door openings ahead of the expected rain at Washington Dulles International Airport, Saturday, April 21, 2012, in Sterling, Va. Enterprise, the first orbiter built for the Space Shuttle Program, was used primarily for ground and flight tests within the atmosphere. The initial testing period named Approach and Landing Test (ALT) included a flight on February 18, 1977 atop a Shuttle Carrier Aircraft (SCA) to measure structural loads and ground handling and braking characteristics of the mated system. Enterprise will go on permanent display at the Intrepid Sea Air and Space Museum in New York in June. Photo Credit: (NASA/Bill Ingalls)

Workers monitor the lift of the space shuttle Discovery from the top of the NASA 747 Shuttle Carrier Aircraft (SCA) at Washington Dulles International Airport, Thursday, April 19, 2012, in Sterling, VA. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) taxis in front of the main terminal at Washington Dulles International Airport, Tuesday, April 17, 2012, in Sterling, Va. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Smithsonian Institution/Eric Long)

The space shuttle Enterprise is seen mated on top of the NASA 747 Shuttle Carrier Aircraft (SCA) at Washington Dulles International Airport, Saturday, April 21, 2012, in Sterling, Va. Space Shuttle Transition and Retirement engineers Saturday completed the final steps to ready Space Shuttle Enterprise for its flight to New York’s John F. Kennedy International Airport while managers continue to evaluate the expected weather that has postponed delivery past Monday. Enterprise, the first orbiter built for the Space Shuttle Program, was used primarily for ground and flight tests within the atmosphere. The initial testing period named Approach and Landing Test (ALT) included a flight on February 18, 1977 atop a Shuttle Carrier Aircraft (SCA) to measure structural loads and ground handling and braking characteristics of the mated system. Enterprise will go on permanent display at the Intrepid Sea Air and Space Museum in New York in June. Photo Credit: (NASA/Bill Ingalls)

Workers monitor the lift of the space shuttle Discovery from the top of the NASA 747 Shuttle Carrier Aircraft (SCA) at Washington Dulles International Airport, Thursday, April 19, 2012, in Sterling, VA. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

The space shuttle Discovery is suspended from a sling held by two cranes shortly after the NASA 747 Shuttle Carrier Aircraft (SCA) was pushed back from underneath at Washington Dulles International Airport, Thursday, April 19, 2012, in Sterling, VA. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) lands at Washington Dulles International Airport, Tuesday, April 17, 2012, in Sterling, Va. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Smithsonian Institution/Eric Long)

The space shuttle Discovery is suspended from a sling held by two cranes as the NASA 747 Shuttle Carrier Aircraft (SCA) is pushed back from underneath at Washington Dulles International Airport, Thursday, April 19, 2012, in Sterling, VA. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Enterprise, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA), is seen prior to taking off for New York from Washington Dulles International Airport, Friday, April 27, 2012, in Sterling, VA. Enterprise was the first shuttle orbiter built for NASA performing test flights in the atmosphere and was incapable of spaceflight. Originally housed at the Smithsonian's Steven F. Udvar-Hazy Center, Enterprise will be demated from the SCA and placed on a barge that will eventually be moved by tugboat up the Hudson River to the Intrepid Sea, Air & Space Museum in June. Photo Credit: (NASA/Scott Andrews)

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) lands at Washington Dulles International Airport, Tuesday, April 17, 2012, in Sterling, Va. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Smithsonian Institution/Eric Long)

Workers monitor the lift of the space shuttle Discovery from the the NASA 747 Shuttle Carrier Aircraft (SCA) at Washington Dulles International Airport, Thursday, April 19, 2012, in Sterling, VA. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

Workers use two cranes to position the sling that will be used to demate the space shuttle Discovery, Monday, April 16, 2012, at the Apron W area of Washington Dulles international Airport in Sterling, Va. The sling will be used to demate the space shuttle Discovery from the 747 Shuttle Carrier Aircraft (SCA) once it arrives. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) lands at Washington Dulles International Airport, Tuesday, April 17, 2012, in Sterling, Va. The Steven F. Udvar-Hazy Center is seen in the background. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Smithsonian Institution/Eric Long)

Space shuttle Enterprise, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA), is seen prior to taking off for New York from Washington Dulles International Airport, Friday, April 27, 2012, in Sterling, VA. Enterprise was the first shuttle orbiter built for NASA performing test flights in the atmosphere and was incapable of spaceflight. Originally housed at the Smithsonian's Steven F. Udvar-Hazy Center, Enterprise will be demated from the SCA and placed on a barge that will eventually be moved by tugboat up the Hudson River to the Intrepid Sea, Air & Space Museum in June. Photo Credit: (NASA/Scott Andrews)

Space Shuttle Discovery mounted atop a 747 Shuttle Carrier Aircraft (SCA) approaches the runway for landing at Washington Dulles International Airport, Tuesday April 17, 2012, in Sterling, Va. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Paul E. Alers)

NASA Deputy Administrator Lori Garver, at podium, speaks to those in attendance at Apron W after the 747 Shuttle Carrier Aircraft (SCA) with space shuttle Discovery mounted on top rolled to a halt at Washington Dulles International Airport, Tuesday, April 17, 2012 in Sterling, Va. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Smithsonian Institution/Dane Penland)

The space shuttle Enterprise is seen mated on top of the NASA 747 Shuttle Carrier Aircraft (SCA) at Washington Dulles International Airport, Saturday, April 21, 2012, in Sterling, Va. Painted graphics line the side of NASA 905 depicting the various ferry flights the Shuttle Carrier Aircraft has supported during the Space Shuttle Program, including the tests using the space shuttle prototype Enterprise. Space Shuttle Transition and Retirement engineers Saturday completed the final steps to ready Space Shuttle Enterprise for its flight to New York’s John F. Kennedy International Airport while managers continue to evaluate the expected weather that has postponed delivery past Monday. Enterprise, the first orbiter built for the Space Shuttle Program, was used primarily for ground and flight tests within the atmosphere. The initial testing period named Approach and Landing Test (ALT) included a flight on February 18, 1977 atop a Shuttle Carrier Aircraft (SCA) to measure structural loads and ground handling and braking characteristics of the mated system. Enterprise will go on permanent display at the Intrepid Sea Air and Space Museum in New York in June. Photo Credit: (NASA/Bill Ingalls)

The space shuttle Discovery is suspended from a sling held by two cranes shortly after the NASA 747 Shuttle Carrier Aircraft (SCA) was pushed back from underneath at Washington Dulles International Airport, Thursday, April 19, 2012, in Sterling, VA. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

The space shuttle Discovery is suspended from a sling held by two cranes shortly after the NASA 747 Shuttle Carrier Aircraft (SCA) was pushed back from underneath at Washington Dulles International Airport, Thursday, April 19, 2012, in Sterling, VA. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)