US Air Force will use lower cost Spacex to launch the X-37B unmanned spaceplane

The Air Force has selected SpaceX to launch the secretive X-37B unmanned spaceplane on its fifth mission to orbit, according to Spaceflight Now. The Falcon 9 Upgrade or Full Thrust that will be used is taller and more powerful than previous versions of SpaceX's primary launch vehicle. The Full Thrust has been launched before, carrying large payloads such as one of the Inmarsat-5 satellites.

The Air Force has two X-37Bs, and these reusable, uncrewed orbital vehicles generally spend hundreds of days in orbit at a time. During the craft's fourth and most recent mission, it orbited the planet for 718 days before landing on a runway used by the space shuttle program at NASA's Kennedy Space Center in Florida last month.

The X-37B spaceplane, also known as the Orbital Test Vehicle (OTV), is similar in shape to NASA's space shuttle but about a fourth of the size.