Orbital Test Vehicle 8 (OTV-8), also referred to as United States Space Force-36 (USSF-36) or USA-555, is the fourth flight of the first Boeing X-37B, an American unmanned vertical-takeoff, horizontal-landing spaceplane. It was launched to a low Earth orbit (LEO) aboard a Falcon 9 Block 5 rocket (for the first time) from LC-39A on August 22, 2025.
The spaceplane is operated by the United States Space Force, which considers the mission classified and as such has not revealed the objectives.
Payloads and experiments Onboard experiments include a laser communications demo in low Earth orbit for more efficient and secure communications in future and the second experiment is to demonstrate world's highest performing quantum inertial sensor ever used in space, this system will help improving navigation by detecting rotation and acceleration of atoms.
See also List of USSF launches List of USA satellites (501-1000), for USA-555 OTV-1 OTV-2 OTV-3 OTV-4 OTV-5 OTV-6 OTV-7
References