Little is known about the US Air Force’s X-37B which ended its first mission three months ago. However, the craft is set to fly again on an unknown mission for unknown reasons.
Pending weather, the X-37B orbiter will launch March 4 on an Atlas V rocket from Cape Canaveral. The Air Force has waited no time at all following the first successful launch. Successful being relative, since no one outside the program knows what the mission entailed.
More at link:
http://rt.com/usa/news/usa-x37b-space-craft-air-force/