The US Air Force has confirmed that its X-37B spacecraft designated Orbital Test Vehicle 3 has glided back to Earth and landed at 0924 PT (1724 UTC) at Vandenberg Air Force Base.
"The landing of OTV-3 marks a hallmark event for the program," said the unnamed X-37B program manager in a statement.
"The mission is our longest to date and we're pleased with the incremental progress we've seen in our testing of the reusable space plane. The dedication and hard work by the entire team has made us extremely proud."
The X-37B spacecraft looks somewhat like a scaled down version of the space shuttle, although at 29 feet long it's about a third of the size. The unmanned spacecraft was launched from Cape Canaveral on 11 December 2012 atop an Atlas V rocket and the Air Force won’t say what it was doing for so long in space, other than it was conducting "in-orbit experiments."
One of those experiments was undoubtedly answering the question "how long can the thing stay in orbit and still function," but other than that everyone outside the program is in the dark. It has been suggested that the spacecraft is an orbital weapons platform intended to take out satellites but there's no evidence of this.
It's not really large enough to grab enemy satellites for examination, although it's certainly conceivable that the X-37B could carry weaponry capable of taking out enemy birds. But that's a last-resort situation, once you start blowing up satellites then the clouds of debris created can be equally deadly to friend or foe in orbit.
What's more likely is that the X37-B is an observation platform that can be easily maneuvered around in orbit. The spacecraft has a large fuel tank – in comparison to most reconnaissance satellites – and could be moved around in orbit to check out new targets before being refueled and sent back up.
After its record-breaking trip the OTV 3 will be taken back to Boeing's laboratories for analysis and refurbishment. The Air Force says the next mission is planned for 2015. ®