Magnum was a class of

SIGINT Signals intelligence (SIGINT) is intelligence-gathering by interception of '' signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication ...

spy satellite A reconnaissance satellite or intelligence satellite (commonly, although unofficially, referred to as a spy satellite) is an Earth observation satellite or communications satellite deployed for military or intelligence applications. The ...

s reportedly operated by the

National Reconnaissance Office The National Reconnaissance Office (NRO) is a member of the United States Intelligence Community and an agency of the United States Department of Defense which designs, builds, launches, and operates the reconnaissance satellites of the U.S. fe ...

(NRO) for the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

Central Intelligence Agency The Central Intelligence Agency (CIA ), known informally as the Agency and historically as the Company, is a civilian foreign intelligence service of the federal government of the United States, officially tasked with gathering, processing, ...

(CIA). The program remains classified, and the information that exists is speculative.

Launch

It is believed that two Magnum satellites were launched from

Space Shuttle Discovery Space Shuttle ''Discovery'' ( Orbiter Vehicle Designation: OV-103) is one of the orbiters from NASA's Space Shuttle program and the third of five fully operational orbiters to be built. Its first mission, STS-41-D, flew from August 30 to S ...

(OV-103) during the missions

STS-51-C STS-51-C (formerly STS-10) was the 15th flight of NASA's Space Shuttle program, and the third flight of Space Shuttle ''Discovery''. It launched on January 24, 1985, and made the fourth shuttle landing at Kennedy Space Center, Florida, on Janu ...

in 1985 and

STS-33 STS-33 was a NASA Space Shuttle mission, during which Space Shuttle ''Discovery'' deployed a payload for the United States Department of Defense (DoD). It was the 32nd shuttle mission overall, the ninth flight of ''Discovery'', the fifth shutt ...

in 1989. The satellites reportedly have a mass of , operating in near- geosynchronous orbits, using

Inertial Upper Stage The Inertial Upper Stage (IUS), originally designated the Interim Upper Stage, was a two-stage, solid-fueled space launch system developed by Boeing for the United States Air Force beginning in 1976 for raising payloads from low Earth orbit to ...

s (IUS) to get from the shuttle's orbit to the higher geosynchronous orbit. According to Jim Slade of

ABC News ABC News is the news division of the American broadcast network ABC. Its flagship program is the daily evening newscast ''ABC World News Tonight, ABC World News Tonight with David Muir''; other programs include Breakfast television, morning ...

, the second satellite, USA-48, replaced the first, USA-8, which after more than 4 years in orbit was running out of maneuvering fuel required for keeping its station over the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...

. The mission of the two satellites was to listen in to military and diplomatic communications from the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

, China, and neighbouring countries.

USA-67 satellite

USA-67, launched aboard Space Shuttle Atlantis (OV-104) in November 1990 ( STS-38 mission), was initially identified as a third Magnum satellite owing to the presence of two upper stages in orbit after its deployment, suggesting that an Inertial Upper Stage (IUS) had been used to deploy it. It was later determined that the second upper stage was from the stealthy

Prowler Prowler may refer to: * "Prowler", a song by Iron Maiden from ''Iron Maiden'', 1980 * Prowler (Marvel Comics), a Marvel Comics superhero * ''The Prowler'' (1951 film), a film starring Van Heflin * "The Prowler" (''Australian Playhouse''), an e ...

spacecraft, and that USA-67 was a

Satellite Data System The Satellite Data System (SDS) is a system of United States military communications satellites. At least three generations have been used: SDS-1 from 1976 to 1987; SDS-2 from 1989 to 1996; SDS-3 from 1998 to the present. It is believed that ...

(SDS-2)

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth ...

Contractor

The Magnum satellites, built by TRW, are rumored to have large (estimated diameter)Spy satellites of the NSA
(fr) umbrella-like reflecting dishes to collect RF

signals In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The ''IEEE Transactions on Signal Processing'' ...

from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. The Magnum/Orion satellites replaced the older Rhyolite/Aquacade series of SIGINT satellites, and have themselves been succeeded by the Mentor/''Advanced Orion'' satellites.

Satellites

References

External links