Jumpseat
Spacecraft · USA
Original archive entry. The text, images and links below are kept as they were written.
American military signals intelligence satellite. Jumpseat signals intelligence satellites were launched by Titan 3B or 34B into highly elliptic Molniya-type orbits.Built by Hughes for USAF, USA. Launched 1971 - 1983. Used HS-318 bus.
These orbits were very similar to those of SDS classified communications/data relay satellites, and identification of a launch in either series as SDS or Jumpseat may differ from analyst to analyst.
Jumpseat satellites were reportedly about 2 m x 2 m x 4 m in dimension, with two large solar wings and a large primary parabolic antenna. In their elliptical orbits they would move very slowly over the northern hemisphere for most of their orbital period, allowing interception of microwave line-of-sight communications beams. Since they would move slowly through the beams during their orbit, a constellation of such satellites was required to monitor Soviet communications throughout the day. What could be intercepted at any particular time of day would depend on which satellites were in a position to monitor which beams. The satellites also probably integrated ELINT and other SIGINT functions and intercepted up- or down-links from Soviet Molniya strategic communications satellites. Receiving stations were established in Pine Gap, near Alice Springs, Australia; Bad Aibling, Germany, Menwith Hill, Yorkshire, England; and Misawa, Japan. Jumpseat and other US COMINT satellites became less important during the 1980's, as the Soviet Union moved to replace interceptable radio communication links with conventional or fiber-optic cables.
More at: Jumpseat.
Related
- Family
- Molniya orbit, SIGINT
- Country
- USA
- Launch Sites
- Vandenberg, Vandenberg SLC4W
- Agency
- USAF
Chronology
7 events
1971 March 21
03:45 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 33B.- Jumpseat 1 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO, USAF. Class: Surveillance. Type: SIGINT. Spacecraft: Jumpseat. USAF Sat Cat: 5053 . COSPAR: 1971-021A. Apogee: 33,800 km (21,000 mi). Perigee: 390 km (240 mi). Inclination: 63.20 deg. Period: 596.70 min.
1972 February 16
09:59 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 33B. FAILURE: Failure.- Jumpseat 2 - . Payload: OPS 1844. Mass: 700 kg (1,540 lb). Nation: USA. Agency: USAF. Class: Surveillance. Type: SIGINT. Spacecraft: Jumpseat.
1973 August 21
16:07 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 33B.- Jumpseat 3 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO, USAF. Class: Surveillance. Type: SIGINT. Spacecraft: Jumpseat. USAF Sat Cat: 6791 . COSPAR: 1973-056A. Apogee: 39,296 km (24,417 mi). Perigee: 460 km (280 mi). Inclination: 63.30 deg. Period: 705.70 min.
1975 March 10
04:41 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 34B.- Jumpseat 4 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO, USAF. Class: Surveillance. Type: SIGINT. Spacecraft: Jumpseat. USAF Sat Cat: 7687 . COSPAR: 1975-017A. Apogee: 39,337 km (24,442 mi). Perigee: 295 km (183 mi). Inclination: 63.50 deg. Period: 702.00 min.
1978 February 25
05:00 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 34B.- Jumpseat 5 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO, USAF. Class: Surveillance. Type: SIGINT. Spacecraft: Jumpseat. USAF Sat Cat: 10688 . COSPAR: 1978-021A. Apogee: 39,377 km (24,467 mi). Perigee: 311 km (193 mi). Inclination: 63.20 deg. Period: 703.70 min. Or Quasar..
1981 April 24
21:32 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 34B.- Jumpseat 6 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO, USAF. Class: Surveillance. Type: SIGINT. Spacecraft: Jumpseat. USAF Sat Cat: 12418 . COSPAR: 1981-038A. Apogee: 708 km (439 mi). Perigee: 188 km (116 mi). Inclination: 62.70 deg. Period: 93.00 min. SDS 4 not deployed..
1983 July 31
15:41 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 34B.- Jumpseat 7 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO, USAF. Class: Surveillance. Type: SIGINT. Spacecraft: Jumpseat. USAF Sat Cat: 14237 . COSPAR: 1983-078A. Apogee: 39,321 km (24,432 mi). Perigee: 1,028 km (638 mi). Inclination: 63.40 deg. Period: 717.10 min. Or Quasar.