X-37B Lifts Off on Eighth Mission

The U.S. Space Force’s X-37B Orbital Test Vehicle lifted off from Kennedy Space Center just before midnight on its eighth flight, OTV-8. Looking like a small space shuttle, the spaceplane was nestled inside the fairing of a SpaceX Falcon 9 rocket. The USSF released a pre-launch photo and shared a few nuggets about some of the experiments aboard, but little is known about what these X-37B missions do during their lengthy flights.

Liftoff of OTV-8, also designated USSF-36, was at 11:50 pm ET on August 21 (August 22, 03:50 UTC).

Liftoff! pic.twitter.com/oQFgBJqWg3

— SpaceX (@SpaceX) August 22, 2025

Last week the USSF shared this photo of the X-37B inside the Falcon 9 fairing.

Just seven days until the eighth mission of the #X37B launches from Kennedy Space Center. Final preparations by AFRCO, in partnership with USSF, SSC and @spacex, are underway to launch on Aug. 21. #USSF36

More: https://t.co/3BPVZZYCs9 pic.twitter.com/Fh6vaRaPdY

— United States Space Force (@SpaceForceDoD) August 14, 2025

SpaceX posted photos of the rocket on the pad waiting for launch. Unlike OTV-7, this mission is using a standard Falcon 9, not the more powerful Falcon Heavy. OTV-7 was placed into a highly elliptical orbit, which requires more energy than a typical orbit. The USSF hasn’t disclosed OTV-8’s destination, but based on navigational warnings Marco Longbroek, a Dutch amateur satellite tracker and lecturer in space situational awareness, concludes it’s going to a 49.5 degree inclination.

Falcon 9 vertical at pad 39A in Florida ahead of Thursday’s launch of the X-37B Orbital Test Vehicle → https://t.co/5LeM34ctYw pic.twitter.com/3Tnsp7w7Ni

— SpaceX (@SpaceX) August 21, 2025

The USSF said OTV-8 has “a wide range of test and experimentation objectives” including “demonstrations of high-bandwidth inter-satellite laser communications technologies and enhanced space navigation using the highest performing quantum inertial sensor in space.”

In August 23, Scott Tilley, an amateur satellite observer in Canada, posted on X that OTV-8 deployed a payload — “likely LIMASAT” — along with a video.

 

X-37B OTV-8 has deployed a payload.

Likely LIMASAT (first object in video) which was attached to the service module.

The objects are running a ~150s late on the @Marco_Langbroek post launch TLE. OTV8 is the brighter object just as the video ends.

RASA 8″, time PDT… pic.twitter.com/p7SfrR5hF1

— Scott Tilley ???????? ???????? (@coastal8049) August 23, 2025

The first six flights successively extended the on-orbit duration of the X-37B to two-and-a-half years, but the most recent flight, OTV-7, was shorter. That flight conducted aerobraking maneuvers, but what impact that had on the mission timeline hasn’t been revealed.

First flight: 2010, 224 days
Second flight: 2011-2012, 469 days
Third flight: 2012-2014 674 days
Fourth flight: 2015-2017, 718 days
Fifth flight: 2017-2019, 780 days
Sixth flight: 2020-2022, 908 days
Seventh flight: 2023-2025, 434 days

The USSF summarized the achievements of the previous missions in very broad terms.

The X-37B program, which first launched in April 2010, has accrued 4,208 days in operation. Previous X-37B missions have successfully demonstrated the X-37B spacecraft’s ability to alter its orbital trajectory using a novel aerobraking maneuver, experimented with space domain awareness technologies, successfully tested Naval Research Laboratory technology designed to harness solar energy and transmit power to the ground, and subjected seeds to the radiation environment of space for the purpose of better understanding how to sustain humans on long-term crewed missions to the moon and beyond.

The X-37B is a dynamic and responsive spacecraft responsible for conducting a range of tests and experiments that expedite the development of critical next-generation technologies and operational concepts for reusable space capabilities. — U.S. Space Force

The Boeing-built X-37B looks like a small space shuttle because it originated at NASA in 1999 to develop a reusable, uncrewed spaceplane as a test designed to lead to an Orbital Space Plane that could bring International Space Station astronauts back to Earth in an emergency and, eventually, as a taxi to take them to the ISS as well.

NASA terminated the X-37 in 2004 after President George W. Bush announced a change in strategy for the human spaceflight program that included terminating the U.S. Space Shuttle as soon as construction of the International Space Station was completed. The program was transferred to the Defense Advanced Research Projects Agency (DARPA) and later taken over by the Air Force’s Rapid Capabilities Office (AFRCO). Today’s flight is a partnership between USSF and the AFRCO.

Boeing built two X-37Bs, OTV-1 and OTV-2. The USSF didn’t specify which is being used for this mission.

Speculation is rampant about what the X-37B does during all the months or years it’s in orbit because of the secrecy that surrounds it and the fact that it’s maneuverable. Some question whether it may be a space weapon of some kind.

The Secure World Foundation tracks global counterspace capabilities and concludes that’s not likely.  An SWF fact sheet on X-37B points out there “is no public evidence that it has ever approached or interacted with other space objects” and “publicly available data suggests most activity supports technology development, not weapons testing.”

 

This article has been updated.

Clarification:  The original version of this article said X-37B was based on NASA’s Orbital Space Plane program, but it was an uncrewed test vehicle intended to lead to the OSP, which would have been crewed.  The OSP also was terminated because of Bush’s change in strategy, which shifted focus to the Constellation program to return humans to the Moon by 2020 instead of ISS operations.