Unmanned US space plane lands after 22-month orbit
US military's X-37B lands in California after classified 22-month mission
A top-secret US robot space plane landed back on earth on Friday after a 22-month orbit, although the craft's mission remains shrouded in mystery.
The unmanned X-37B, which looks like a miniature space shuttle, glided into Vandenberg Air Force Base in California on Friday. The vehicle was launched on December 11, 2012, on a mission that military officers say is still strictly secret.
"I'm extremely proud of our team for coming together to execute this third safe and successful landing," Colonel Keith Balts, commander of the US military's 30th Space Wing, said after the touchdown.
Analysts say the X-37B, which is also known as the Orbital Test Vehicle, could be a platform for spying from space, including possibly snooping on other countries' satellites.
But officials have previously denied the project had anything to do with creating a "space weapon" that could knock down other satellites.
The US Air Force says the X-37B can test technology for "reusable" spacecraft and conduct unspecified experiments that can be studied on earth.
It said the orbiters "perform risk reduction, experimentation and concept-of-operations development for reusable-space-vehicle technologies".