The Air Force's Mysterious X-37B Spaceplane Celebrates Its First Full Year in Orbit

Well, we're celebrating anyhow--there's no telling what it's actually doing

X-37B After Landing

Air Force crews tend to the X-37B secretive space plane after it returned from its maiden voyage Dec. 3, 2010.U.S. Air Force/Michael Stonecypher

NASA may no longer possess a reusable vehicle for traveling to and from low earth orbit, but the United States Air Force has all but established a permanent presence up there. Maybe you've forgotten about the X-37B, the USAF's pilotless, reusable space plane that's been in orbit since launching on March 5, 2011, but it's still up there making laps. Today marks the first day of its second year in continuous orbit, a milestone for the mysterious program that the Air Force will tell us virtually nothing about.

The current flight is the second trip to orbit for the X-37B program and the first for this particular spacecraft, which is sometimes simply called the Orbital Test Vehicle, or OTV. Another X-37B completed a 244-day mission in 2010. The Air Force plans to put that other X-37B back into orbit this fall, but it hasn't said when OTV currently in orbit will be coming back to Earth.

Its current route and ongoing mission are closely guarded secrets--the Air Force simply says the X-37Bs are testing technologies and leaves it at that--but amateur skygazers and satellite watchers say the OTV is looping the Earth on a track common for intelligence satellites. One of the program's goals is presumably to establish methods for quickly and regularly turning a reusable space plane around for multiple, rapid-fire missions into orbit. But its payload bay--the contents of which are unknown outside the program--has the capacity to carry any number of space-based tools.

Maybe X-37B is up there simply observing the weather--but probably not. Whatever you're up to up there, oh intrepid X-37B, here's to your first full year in orbit.