The US Air Force’s mysterious X-37B space plane

The robotic X-37B space plane has been launched in United Launch Alliance Atlas V rocket from Florida’s Cape Canaveral Air Force Station.

It is unclear what exactly the X-37B will be doing as it zooms around Earth, or how long it will remain aloft. Also on board the Atlas V were 10 miniscule “cubesats,” including the LightSail solar sail that was developed by the nonprofit Planetary Society. LightSail aims to prove out key solar-sailing technology ahead of a more ambitious orbital trial next year.

About X-37B space plane :

  1. Length: 29 feet long by 9.5 feet tall (8.8 by 2.9 meters)
  2. Wingspan : 15 feet (4.6 m), a payload bay the size of a pickup-truck bed.
  3. X-37Bs could fit inside the payload bay of NASA’s now-retired space shuttle orbiter..
  4. The X-37B launches vertically and lands horizontally

Air Force officials have not said how long they expect OTV-4 to last, but the mission will be an extended one if the previous X-37B flights are any guide. It’s unclear if OTV-4 will employ the X-37B that flew OTV-1 and OTV-3, or the space plane that flew OTV-2.