GRAB was a U.S. Navy electronic intelligence (ELINT) satellite system that became operational in July 1960 and was operated until August 1962. GRAB was officially declassified in June 1998 during NRL's 75th anniversary celebration. GRAB obtained information on Soviet air defense radars that could not be observed by Air Force and Navy aircraft flying ELINT missions along accessible borders in Europe and the western Pacific.
This ELINT satellite system was proposed by NRL in the spring of 1958. In parallel with exploratory development by NRL, the Office of Naval Intelligence obtained endorsements from elements of the executive and legislative branches of the U.S. government. With positive recommendations from the Department of State, the Department of Defense, and the Central Intelligence Agency, President Eisenhower approved full development in August 1959.
NCST designed and built the GRAB satellite and a network of overseas data collection facilities. The first launch was approved by President Eisenhower in May 1960, just four days after a CIA U-2 aircraft was lost on a reconnaissance mission over Soviet territory. The GRAB satellite got a free ride into space in June 1960 with the Navy's third Transit navigation satellite. GRAB carried two electronic payloads, the classified ELINT package and instrumentation to measure solar radiation (SolRad). The SolRad experiment was publicly disclosed in DoD press releases on this and subsequent launches. Four more launches were attempted, and one was successful on 29 June 1961.
GRAB received each pulse of a radar signal in a certain bandwidth, as sensed by its tiny antennas, and transponded a corresponding signal to collection huts at ground sites within its field of view. Operators in the huts recorded GRAB's transponded information and couriered it to NRL for evaluation. Subsequently, the National Security Agency and the Strategic Air Command exploited GRAB's data to develop technical intelligence about Soviet radar and to develop effective war plans.