Someone just spotted a top-secret Air Force space plane in orbit and we don’t know why it’s there

You can’t keep something completely secret when it’s flying around the planet over and over again. While no one has any idea what the U.S. Air Force’s X-37B space plane (aka Orbital Test Vehicle or OTV) is actually doing in low Earth orbit, astrophotographer Ralf Vandebergh’s satellite tracking paid off when he glimpsed it in the sky after months of hunting robotic spacecraft.

Vandebergh first saw the space plane this May before it unexpectedly disappeared from orbit. The efforts of an amateur satellite observers’ network helped him find it again recently — and now he has photographic evidence.

"It is really a small object, even at only 186 miles’ altitude, so don't expect the detail level of ground-based images of the real space shuttle," Vandebergh told Space.com of the vehicle, which kind of looks like a mini-me of NASA’s retired space shuttle. "We can recognize a bit of the nose, payload bay and tail of this mini-shuttle, with even a sign of some smaller detail.”

Both of the reusable X-37B vehicles in the fleet were built by Boeing, so think about that next time you’re in an airport. They were originally funded by DARPA (Defense Advanced Research Projects Agency), before the program transitioned to the Air Force in 2004. The 29-foot-long space plane is 9.6 feet tall, with a wingspan of around 15 feet and a launch weight of 11,000 pounds. Gallium-arsenide solar cells and lithium-ion batteries fuel it in orbit. What we do know about its classified payload is that the payload bay is 7 feet by 4 feet and can accommodate a robotic arm.

So what is the X-37B doing up there? It's not part of the Space Force ... yet. What we do know is that this mission is the fifth flight, or OTV-5, for the Air Force’s OTV program. The Air Force Space Command’s 3rd Space Experimentation Squadron (sounds like something out of a futuristic spy movie) at Schriever Air Force Base in Colorado handles mission control for these flights. Next to X-37Bs, this squadron handles space-based demos, experiment, pathfinders, information on flying objects above Earth, and other intel for the Space Command.

Does that mean the OTV is trying to get an eyeful of Earth as it looks both downward and upward? Possibly. The Air Force did release information about OTV-5 being launched into the highest-inclination orbit one of these vehicles has flown in. That still doesn’t give a clue about its payload.

The only OTV-5 payload that was ever declassified was ASETS-II (Advanced Structurally Embedded Thermal Spreader), which tested how long experimental electronics developed by the U.S. Air Force Research Laboratory (AFRL) could endure in space.

For all we know, the X-37B could be up there for any amount of time, since mission duration is also classified. The only thing that is floating around on the internet is that OTV-6 should be taking off sometime this year from Cape Canaveral Air Force Station’s Space Launch Complex-41.

Maybe you'll catch that one when you look up at the sky.

(via LiveScience)