The X-375B is an unmanned spacecraft. It was launched from Cape Canaveral Air Force Base in March of 2011. It returned June 16, 2012, making an autonomous landing, and Vandenberg Air Force Base. It has now completed a fifteen month clandestine mission.
It had a classified payload on board, which, of course, has led to some speculation about what that might be. Could it have been carrying an experimental spy satellite sensor? Was it doing a reconnaissance mission? Maybe it was gathering intelligence? The answer is anyone’s guess.
The X-375B is an Orbital Test Vehicle, (also called an OTV). It is part of an experimental test program that is being used to demonstrate technologies for a reliable, reusable, unmanned space test platform for the United States Air Force. There are two main purposes of this program: to create reusable spacecraft and to conduct experiments that can be returned to Earth to be examined.
Boeing is the prime contractor that made the X-375B. It stands 9 feet and six inches tall, and is 29 feet and 3 inches wide. It has a wingspan of 14 feet and 11 inches. Overall, it is a stocky, solid, looking spacecraft that weighs 11,000 pounds. The power for the X-375B comes from Gallium Arsenide Solar Cells with lithium-Ion batteries.