The United States Navy's Naval Research Laboratory (NRL) established itself as a player early in the Space Race with the development and management of Project Vanguard (1956–1959),[2] America's first satellite program.

After Vanguard, the Navy's next major goal was to use the observational high ground of Earth's orbit to survey Soviet radar locations and frequencies.

This first space surveillance project was called "GRAB", later expanded into the more innocuous backronym, Galactic Radiation and Background.

The Earth's atmosphere blocks large sections of sunlight's electromagnetic spectrum, making it impossible to study the Sun's X-ray and ultraviolet output from the ground.

Without this critical information, it was difficult to model the Sun's internal processes, which in turn inhibited stellar astronomy in general.

[6]: 5–6  On a more practical level, it was believed that solar flares directly affected the Earth's thermosphere, disrupting radio communications.

Three of the photometers were shielded against Van Allen radiation belts (which could spoil results) by magnets, as had been done on earlier missions.

[12] On 26 April 1962 at 10:49 GMT, Scout X-2 #111 [14] blasted off from Vandenberg Air Force Base Western Test Range.