| Jumpseat |
home
topic index |
|
Class: SIGINT. Destination: Molniya Orbit. Nation: USA. Agency: U.S. Air Force. 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. Typical orbit: 445 x 31973 km, 63.2 deg inclinaton. Mass: 700 kg (1,540 lb). Jumpseat Chronology
Bibliography:
Contact us with any corrections, additions, or comments. Conditions for use of drawings, pictures, or other materials from this site.. To contact astronauts or cosmonauts. © Mark Wade, 1997 - 2008 except where otherwise noted. |