USA-240, also referred to as Orbital Test Vehicle 3 (OTV-3), is the second flight of the first Boeing X-37B, an American unmanned robotic vertical-takeoff, horizontal-landing spaceplane.

It was launched to low Earth orbit aboard an Atlas V rocket from Cape Canaveral on 11 December 2012.

The Air Force stated only that the "mission will incorporate the lessons learned during the refurbishment process on OTV-1.

As the X-37B program is examining the affordability and reusability of space vehicles, validation through testing is vital to the process.

[9][10] The vehicle landed at Vandenberg AFB on 17 October 2014 at 16:24 UTC, having spent just short of 675 days in orbit.