Gravity Probe B
Delta II
United States Air Force
Mission
Gravity Probe B
Type: Astrophysics
Gravity Probe B (GP-B) was a satellite-based experiment to test two unverified predictions of general relativity: the geodetic effect and frame-dragging. This was to be accomplished by measuring, very precisely, tiny changes in the direction of spin of four gyroscopes contained in an Earth-orbiting satellite at 650 km (400 mi) altitude, crossing directly over the poles.
Trajectory
The trajectory is unavailable. Check back for updates.
Location
Space Launch Complex 2W
Vandenberg SFB, CA, USA
728 rockets have launched from Vandenberg SFB, CA, USA.

Agency
United States Air Force – USAF
- Type: Government
- Abbreviation: USAF
- Administration: Commander-in-Chief: President of the US
- Founded: 1947
- Country: USA
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established as a separate branch of the United States Armed Forces in 1947 with the enactment of the National Security Act of 1947.