WATCH Live: Space Force Launch to Send X-37B Back into Orbit

The Space Force’s X-37B is ready to return to orbit. 

The secretive spaceplane is set to blast off atop a SpaceX Falcon 9 rocket from Kennedy Space Center, Fla., at around 11:50 p.m. local time on Aug. 21.  

A livestream of the launch will begin at 11:30 p.m. Eastern time, and can be viewed here: 

Watch Falcon 9 launch the USSF-36 mission to orbit https://t.co/7w2HkqTjsh

— SpaceX (@SpaceX) August 20, 2025

This will be the X-37B’s eighth flight, and judging from history, it will be a long time before it returns to Earth. All of its missions have lasted at least seven months, with most of them extending beyond a year. On two occasions, it even spent more than two years in space. 

Many of the payloads on X-37B are classified, but officials have disclosed two objectives for the latest mission: laser communications demonstrations in low-Earth orbit and tests of a quantum inertial sensor. 

Both experiments will feed into cutting-edge technology the Space Force is pursuing. Laser comms is considered vital to proliferated constellations like the one being built by the Space Development Agency, and quantum sensing could be a way to ensure position, navigation, and timing, without relying on the Global Positioning System. 

Chief of Space Operations Gen. B. Chance Saltzman posted on social media last month that the X-37B mission is “about making our joint force more connected, more resilient, and ready to operate in the face of any challenge.” 

The launch will also mark the second National Security Space Launch mission in 10 days, after a Vulcan Centaur rocket lifted off Aug. 12 from Cape Canaveral Space Force Station, Fla. NSSL missions have come in batches this year—three in eight days in April, two in four days in March.  

The cadence is expected to stay high over the next couple months as SDA prepares to launch “Tranche 1” of its constellation, which includes scores of data transport and missile warning and tracking satellites.