US Air Force’s X-37B space plane just landed at the Kennedy Space Center in Florida on May 7, it set a new record for orbital endurance for a reusable unmanned spacecraft. The spacecraft was on the Orbital Test Vehicle mission 4 (OTV-4), and the 718 days it spent in the orbit until the fully autonomous touchdown on Sunday morning 8:00 AM EDT is the longest in the history of the OTV classified mission.
The Boeing-built X-37B is designed for an orbital lifetime of 270 days according to the Air Force’s fact sheet. The craft is used for the Air Force studies in spaceflight risk reduction, orbital experiments, and operations development.
On the fourth OTV mission, the X-37B was launched atop the Atlas V rocket on May 20, 2015, from the Cape Canaveral Air Force Station, Florida. Since the mission was classified, too many details were never revealed, but the aim of the mission was to test the Aerojet Rocketdyne XR-5A Hall-effect thruster, which is a part of the Advanced Extremely High-Frequency communications satellite program. The shuttle also performed some material tests for NASA.
The X-37B another mission will be launched from Cape Canaveral Air Force Station later this year.