The Air Force’s X-37B Orbital Test Vehicle mission 4 landed at NASA’s Kennedy Space Center Shuttle Landing Facility May 7, 2017.

The X-37B Orbital Test Vehicle, or OTV, is an experimental test program to demonstrate technologies for a reliable, reusable, unmanned space test platform for the USAF. The OTV-4 conducted on-orbit experiments for 718 days during its mission, extending the total number of days spent on-orbit for the OTV program to 2,085 days.

The X-37B is the newest and most advanced re-entry spacecraft. Managed by the Air Force Rapid Capabilities Office.