Encyclopedia Astronautica
Jumpseat


American military naval signals reconnaisance satellite. 7 launches, 1971.03.21 (Jumpseat 1) to 1983.07.31 (Jumpseat 7). Jumpseat signals intelligence satellites were launched by Titan 3B or 34B into highly elliptic Molniya-type orbits.

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 interceptible radio communication links with conventional or fiber-optic cables.

Gross mass: 700 kg (1,540 lb).
First Launch: 1971.03.21.
Last Launch: 1983.07.31.
Number: 7 .

More... - Chronology...


Associated Countries
See also
  • Titan The Titan launch vehicle family was developed by the United States Air Force to meet its medium lift requirements in the 1960's. The designs finally put into production were derived from the Titan II ICBM. Titan outlived the competing NASA Saturn I launch vehicle and the Space Shuttle for military launches. It was finally replaced by the USAF's EELV boosters, the Atlas V and Delta IV. Although conceived as a low-cost, quick-reaction system, Titan was not successful as a commercial launch vehicle. Air Force requirements growth over the years drove its costs up - the Ariane using similar technology provided lower-cost access to space. More...

Associated Launch Vehicles
  • Titan American orbital launch vehicle. The Titan launch vehicle family was developed by the United States Air Force to meet its medium lift requirements in the 1960's. The designs finally put into production were derived from the Titan II ICBM. Titan outlived the competing NASA Saturn I launch vehicle and the Space Shuttle for military launches. It was finally replaced by the USAF's EELV boosters, the Atlas V and Delta IV. Although conceived as a low-cost, quick-reaction system, Titan was not successful as a commercial launch vehicle. Air Force requirements growth over the years drove its costs up - the Ariane using similar technology provided lower-cost access to space. More...
  • Titan 33B American orbital launch vehicle. Basic Titan 3A core, except guidance provided by the Agena upper stage. The Agena and its payload were completely enclosed in a new 3.05 m diameter shroud. 'Ascent Agena' seperated after orbital insertion and did not remain attached to the payload. More...
  • Titan 34B American orbital launch vehicle. Stretched Titan core, originally developed for Titan 3M MOL, with Agena D upper stage. Guidance provided by the Agena upper stage. The Agena and its payload were completely enclosed in a 3.05 m diameter shroud. 'Ascent Agena' seperated after orbital insertion and did not remain attached to the payload. More...

Associated Manufacturers and Agencies
  • USAF American agency overseeing development of rockets and spacecraft. United States Air Force, USA. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • McDowell, Jonathan, Launch Log, October 1998. Web Address when accessed: here.

Associated Launch Sites
  • Vandenberg Vandenberg Air Force Base is located on the Central Coast of California about 240 km northwest of Los Angeles. It is used for launches of unmanned government and commercial satellites into polar orbit and intercontinental ballistic missile test launches toward the Kwajalein Atoll. More...
  • Vandenberg SLC4W Titan, Atlas launch complex. First designated PALC2-3 and used to launch Atlas Agena D with KH-7 spysats. Rebuilt in 1966 to handle Titan 3B with various military payloads. From 1988 used to launch refurbished surplus Titan 2 ICBM's in space launch role. More...

Jumpseat Chronology


1971 March 21 - . 03:45 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 33B. LV Configuration: Titan 33B 33B-1 (3B-36) / Ascent Agena D.
  • Jumpseat 1 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO; USAF. Class: Military. Type: Military naval signals reconnaisance satellite. Spacecraft: Jumpseat. USAF Sat Cat: 5053 . COSPAR: 1971-021A. Apogee: 33,800 km (21,000 mi). Perigee: 390 km (240 mi). Inclination: 63.2000 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. LV Configuration: Titan 33B 33B-2 (3B-37). FAILURE: Failure.
  • Jumpseat 2 - . Payload: OPS 1844. Mass: 700 kg (1,540 lb). Nation: USA. Agency: USAF. Class: Military. Type: Military naval signals reconnaisance satellite. Spacecraft: Jumpseat. COSPAR: F720216A.

1973 August 21 - . 16:07 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 33B. LV Configuration: Titan 33B 33B-3 (3B-38) / Ascent Agena D.
  • Jumpseat 3 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO; USAF. Class: Military. Type: Military naval signals reconnaisance satellite. Spacecraft: Jumpseat. USAF Sat Cat: 6791 . COSPAR: 1973-056A. Apogee: 39,296 km (24,417 mi). Perigee: 460 km (280 mi). Inclination: 63.3000 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. LV Configuration: Titan 34B 34B-1 (3B-50) / Ascent Agena D.
  • Jumpseat 4 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO; USAF. Class: Military. Type: Military naval signals reconnaisance satellite. Spacecraft: Jumpseat. USAF Sat Cat: 7687 . COSPAR: 1975-017A. Apogee: 39,337 km (24,442 mi). Perigee: 295 km (183 mi). Inclination: 63.5000 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. LV Configuration: Titan 34B 34B-2 (3B-49) / Ascent Agena D.
  • Jumpseat 5 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO; USAF. Class: Military. Type: Military naval signals reconnaisance satellite. Spacecraft: Jumpseat. USAF Sat Cat: 10688 . COSPAR: 1978-021A. Apogee: 39,377 km (24,467 mi). Perigee: 311 km (193 mi). Inclination: 63.2000 deg. Period: 703.70 min.

1981 April 24 - . 21:32 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 34B. LV Configuration: Titan 34B 34B-8 (3B-60) / Ascent Agena D.
  • Jumpseat 6 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO; USAF. Class: Military. Type: Military naval signals reconnaisance satellite. Spacecraft: Jumpseat. USAF Sat Cat: 12418 . COSPAR: 1981-038A. Apogee: 708 km (439 mi). Perigee: 188 km (116 mi). Inclination: 62.7000 deg. Period: 93.00 min. Summary: SDS 4 not deployed..

1983 July 31 - . 15:41 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC4W. LV Family: Titan. Launch Vehicle: Titan 34B. LV Configuration: Titan 34B 34B-9 (3B-65) / Ascent Agena D.
  • Jumpseat 7 - . Mass: 700 kg (1,540 lb). Nation: USA. Agency: NRO; USAF. Class: Military. Type: Military naval signals reconnaisance satellite. Spacecraft: Jumpseat. USAF Sat Cat: 14237 . COSPAR: 1983-078A. Apogee: 39,321 km (24,432 mi). Perigee: 1,028 km (638 mi). Inclination: 63.4000 deg. Period: 717.10 min.

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