Earlier this month, the U.S. Air Force's super-secretive Boeing-built X-37B space drone came back to Earth after nearly two years in orbit. For its next trick, Boeing plans to collaborate with the Defense Advanced Research Projects Agency (DARPA) to create a new spaceplane that will be less mysterious but just as experimental.

The new craft will be called "Phantom Express" and be designed to carry and launch small satellites aboard a plane rather than a rocket. It's kind of like skydiving, but when this plane's passenger gets pushed out the door at the edge of space, it doesn't fall to the ground.

After dropping its cargo off in orbit, the plane fires an engine to turn around and return to Earth, landing on a runway to prepare for its next flight, just like a plane or the old space shuttle. In fact, Phantom Express will be equipped with a version of the Space Shuttle main engine, the AR-22 from Aerojet Rocketdyne.

DARPA and Boeing will both invest in the development of the new craft and plan to conduct a demonstration of 10 flights over 10 days at some point in the future.