Success
Gravity Probe B
Astrophysics
United States Air Force(USAF)Government
Delta II 7925
LEOorbit
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.
Tuesday, April 20, 2004 at 4:57 PM
Mission details
Orbital Attempt
#4,653
USAF Mission
#1,060
Pad Launch
#71
Location Launch
#617
Designator
2004-014
Launch Window
NET
Apr 20, 2004, 4:57 PM
Schedule Changes
1 update
Delta II 7925 Specs
Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 variants ("Light" and "Heavy"). The rocket flew its final mission ICESat-2 on 15 September 2018, earning the launch vehicle a streak of 100 successful missions in a row, with the last failure being GPS IIR-1 in 1997.
Length
39 m
Diameter
2.44 m
Launch Mass
219 t
Thrust
3,790 kN
LEO Capacity
3,981 kg
GTO Capacity
1,446 kg
SSO Capacity
3,017 kg
Launch Cost
$51M
Reusable
No
Maiden Flight
1990
Fastest Turnaround
15d 19h
Total Launches
1
Successful
1
Failed
0
Consecutive Success
1
Maiden flight: Feb 14, 1990
United States Air Force
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.
Founded
1947
Administrator
Commander-in-Chief: President of the US
Total Launches
1,078
Successful
972
Failed
106
Pending
0
Consecutive Success
68
Vandenberg SFB, CA, USA
Vandenberg Space Force Base is a United States Space Force Base in Santa Barbara County, California. Established in 1941, Vandenberg Space Force Base is a space launch base, launching spacecraft from the Western Range, and also performs missile testing. The United States Space Force's Space Launch Delta 30 serves as the host delta for the base, equivalent to an Air Force air base wing. In addition to its military space launch mission, Vandenberg Space Force Base also hosts space launches for civil and commercial space entities, such as NASA and SpaceX.
Timezone
America/Los_Angeles
Local Launch Time
Apr 20, 2004, 9:57 AM
Total Launches
885
Total Landings
34
Coordinates
34.7513, -120.5202