The US government has revealed details of a secret satellite program it used to spy on the Soviet Union at the height of geopolitical tensions between the two countries.

The National Reconnaissance Office (NRO) recently declassified its JUMPSEAT spy satellite, eight of which were launched into an elliptical orbit from 1971 to 1987. The Pentagon developed JUMPSEAT as part of the US Air Force’s program, called Project EARPOP, to create satellites capable of intercepting or decrypting electronic emissions from Earth.

“The historical significance of JUMPSEAT cannot be understated,” James Outzen, NRO director of the Center for the Study of National Reconnaissance, said in a statement. “Its orbit gives the US a new vantage point for collecting unique and critical intelligence signals from space.”

Classified orbit

From the moment the Soviet Union launched Sputnik in 1957, the United States has been concerned about space as a potential domain for surveillance and other military activities. JUMPSEAT follows the launch of earlier electronic surveillance satellites: GRAB and POPPY.

The US launched its first satellites into low Earth orbit and needed to collect intelligence from elsewhere in space. JUMPSEAT is designed to operate in an elliptical orbit known as Molniya.

The Molniya satellites have an orbital period of about 12 hours, coming as close as 620 miles (1,000 kilometers) to Earth during perigee and up to about 24,855 miles (40,000 kilometers) from Earth during apogee. Elongated, egg-shaped orbits are ideal for continuous, long-duration coverage of the high-latitude regions of the Northern Hemisphere.

The satellites beam downlinked data to Earth for initial processing. The NRO processes the data before sending it to the Department of Defense, the National Security Agency, and other national security agencies. JUMPSEAT operated in a transponder mode before the NRO took them out of service in 2006.

No more spying

The declassification of NRO memorandum said that the satellites performed admirably during their operation. The agency decided to declassify the spy satellite program because it would not harm current or future satellite programs.

Not all of the satellite’s capabilities, however, are shared with the stated information. Like its predecessors, some of JUMPSEAT’s activities in space remain a mystery.