Thor (rocket family)

[2] On 22 June 1960, a Thor-Ablestar launched the first Galactic Radiation and Background (GRAB) electronic intelligence (ELINT) satellite for the United States Navy.

These now-declassified satellites operated under a cover story of providing solar radiation data and included an electronics package to detect Soviet air defense radar signals.

[3] GRAB-1 was the world's first successful reconnaissance satellite, preceding the first Corona mission to return film (Discoverer 14 on August 18) by almost two months.

Together with the Agena upper stage, Thor was the booster of the Thor-Agena vehicle used to launch the early Corona (also known as "Keyhole" and "Discoverer") satellites from Vandenberg AFB.

It added three Castor solid-fuel rocket strapon boosters—each providing 53,000 lbf (236 kN) thrust—to the standard Thor core stage.

The Thrust-Augmented Long Tank Thor/Agena incorporated modifications allowing 49,000 lb (22,000 kg) more propellant and was capable of sending payloads ranging from 1400 to about 2800 pounds into 100-nautical-mile (190 km) polar circular orbits.