First spy satellite

The first satellite designed to be used for espionage was SOLRAD 1 (aka GRAB 1), which launched on 22 June 1960. This beach-ball sized satellite was designed by the United States Navy's Naval Research Laboratory and was nominally a solar observatory. While it did produce scientific data about x-ray emissions from the Sun, this was just a cover for its primary mission, which was mapping the Soviet Union's air defence radar network.

SOLRAD 1 was both a scientific and military success. The data gathered by its x-ray instruments was enough to determine the Sun's baseline level of x-ray activity. It also determined that variations in earth-bound radio signals were caused by fluctuations in x-ray emissions from the Sun.

The data gathered by the surveillance instruments – which were part of a mission codenamed GRAB ("Galactic Radiation And Background") – revealed that the Soviet Union's air defence radar network was significantly more advanced and extensive than previously estimated. By comparing the strength of radar signals intercepted on different passes, American intelligence analysts were able to roughly pinpoint the location of Soviet radar stations.

The satellite was remotely deactivated in April 1960. It had completed its intelligence objectives and had developed a wobble that made its scientific instruments largely useless. It is still orbiting the Earth. The existence of the GRAB program wasn't declassified until 1998.

Several more satellites were launched as part of the SOLRAD program. The Navy was responsible for SOLRAD satellites 2–5, though only SOLRAD 3 made it into orbit (the rocket carrying SOLRAD 2 crashed in Cuba, causing a major diplomatic incident). SOLRAD satellites 6–11 were pure scientific missions, as by then the intelligence community had switched over to the POPPY series of electronic surveillance satellites.