Galactic Radiation and Background

Galactic Radiation and Background ( GRAB ) refers to the first series of U.S. spy satellites for electronic reconnaissance. They were started in the early 1960s and should inform the radar systems of the Soviet Union, where they camouflage also carried a scientific payload, which is why the satellite official term Galactic Energy Balance Experiment ( Greb -E) and later SOLRAD ( solar radiation ) received.


The 19- kg GRAB satellites, which were developed from 1958 to 1960 from the Naval Research Laboratory (including the engineer Reid D. Mayo ) under the code name Tattletale are generally designed as a sphere with a diameter of 51 cm. The energy supply is provided by a plurality of solar cells, which have been placed such that approximately the same amount of current is generated in each spatial position. This is necessary because the satellite is spin stabilized and can not permanently align with one side to the sun. The exact specifications of the ELINT payload are unknown, but they must have worked at least in a frequency range of 3 GHz, due to the existing Soviet radars. Trapped signals were without buffering forwarded directly to a ground station where they were stored on magnetic tapes. This was then brought by plane to the Naval Research Laboratory, where they were evaluated for the first time. For further analysis, the tapes were then taken to the National Security Agency or the Strategic Air Command, where they were used to improve the education and creating military plans.

The primary entrained to camouflage instruments for the study of X-ray radiation and detecting the Lyman series were fully operational and were used for solar research. The downlink of these instruments was according to the satellite at 108 or 136 megahertz.

The GRAB satellites were launched together with another satellite to most on a launcher Thor Able -Star. The target orbit had an orbital inclination of 66.7 degrees, a perigee of 614 km and an apogee of 1061 km. After the end of the program the satellite Poppy series for ELINT reconnaissance were used.

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