The U.S. Air Force sent its unmanned X-37B spacecraft into orbit for the fourth time on Wednesday
The X-37B is one of two spacecraft, built for the Air Force by Boeing, first launched in 2010. Its mission? That’s a secret.
The two planes have been on three journeys to date: one from April to December of 2010, then from March 2011 to June 2012, and finally a third flight from December 2012 all the way until this past October.
The Air Force has remained mum despite long-running speculation about the purpose of these two spacecraft, the New York Timesreports, and in 2010 the Pentagon denied that the planes have anything to do with weapons. Wednesday’s launch of one of the spacecraft (it is also unknown which of the two launched) happened at Cape Canaveral, Fla.
The X-37B spaceplane was carried into the sky by an American Atlas V rocket. Watch a video of the launch below:
After the original Air Force One, a C-87A Liberator Express nicknamed Guess Where II, was deemed unsafe for presidential use, this Douglas C-54 Skymaster, nicknamed Sacred Cow was introduced for President Franklin D. Roosevelt in 1945. It was equipped with a radio telephone, sleeping area, and elevator for President Roosevelt's wheelchair. Thomas D. McAvoy—The LIFE Picture Collection/Getty ImagesIn 1947, Sacred Cow was replaced with Independence by President Truman, who named it after his hometown. The Douglas DC-6 Liftmaster's nose was painted as a bald eagle.Truman Presidential LibraryPresident Eisenhower added Columbine II, a Lockheed C-121 Super Constellation, to the Presidential fleet in 1953.William J. Smith—APColumbine III, and two smaller Aero Commanders, joined Eisenhower's Presidential planes. Popperfoto/Getty ImagesSpecial Air Mission 26000, a Boeing 707, went into presidential service under the Kennedy administration. SAM 26000 stayed in service through Bill Clinton's administration until 1998. Wally Nelson—APAlthough SAM 26000 remained in service throughout the 1990s, it was replaced as the primary executive aircraft by SAM 27000, the same model aircraft, in 1972. Pictured here is President Ronal Reagan on SAM 27000.TSGT Michael J. Haggerty—APIn 1990, SAM 28000, a Boeing 747 was introduced to the Presidential fleet.Pablo Martinez Monsivais—APSAM 29000, also a Boeing 747, remains President Obama's primary transport aircraft.Raymond Boyd—Getty ImagesIn January, 2015, it was announced that a Boeing 747-8 will take over as the newest member of the Presidential Fleet known as Air Force One.Anthony Bolante—Reuters
