X-37B Orbital Test Vehicle Fact Sheet
The X-37B Orbital Test Vehicle is a reusable robotic spaceplane operated by the United States Space Force. Since its first flight in 2010, the X-37B has conducted seven missions—testing advanced propulsion systems, reusable spacecraft technologies, and military payloads over long-duration spaceflights.
Originally a NASA initiative, the program was transferred to DARPA and then the U.S. Air Force before becoming a Space Force asset. Each mission—designated OTV-1 through OTV-7—has tested different technologies and remained on orbit for increasingly long durations, with OTV-6 reaching 908 days. The most recent mission, OTV-7, operated in a highly elliptical orbit reaching nearly 39,000 km and performed aerobraking maneuvers to reduce orbital debris risk before landing in March 2025.
Key observations from the fact sheet:
- The X-37B deploys small satellites, including military experiments like FalconSAT-8 and microwave power-beaming tests.
- Its payload bay is small, limiting its ability to carry significant counterspace hardware. There is no public evidence that it has ever approached or interacted with other space objects.
- Although the orbit and missions are secretive, publicly available data suggests most activity supports technology development, not weapons testing.
- The vehicle’s maneuverability—including repeated orbit changes and recent aerobraking—is sophisticated, but remains within the scope of responsive space experimentation.
- Some missions have raised transparency concerns, particularly with delayed satellite registration and lack of orbital data during flight.
See page 2 for full flight history table (OTV-1 to OTV-7), including durations and landing sites.
Image of X-37B on runway appears on page 1; orbital rendering of OTV-7 on page 4.
