It's now been a couple of months since the U.S. Air Force's X-37B space plane lifted into orbit amid the expected shroud of secrecy. What's remarkable about this third classified mission in the X-37B program is how little the public knows about it. We don't know how long the craft is supposed to orbit the Earth, and we don't know the mission's objectives. The unmanned space plane ventured into orbit twice before on hush-hush missions for the Air Force. One tidbit that is known: the craft now in Earth orbit was also used during the first X-37B flight in 2010, which lasted almost 225 days.
"The mission is ongoing," Air Force Major Eric Badger, a spokesman for the X-37B program, told Space.com. "As with previous missions, the actual duration will depend on test objectives, on-orbit vehicle performance, and conditions at the landing facility."