SOLRAD (SOLar RADiation) 4B was a solar X-ray, ultraviolet, and electronic surveillance satellite. Developed by the United States Navy's United States Naval Research Laboratory, it was the fifth in both the SOLRAD and the GRAB (Galactic Radiation And Background) programs.

The Scout family of rockets were were American launch vehicles designed to place small satellites into orbit around the Earth. The Scout multistage rocket was the first orbital launch vehicle to be entirely composed of solid fuel stages.

The Navy was competed with the Army to put the first American satellite into orbit. Their first two Vanguard missions failed, with the second being a highly publicized failure, as it exploded on the launchpad. They went on to put 3 satellites into orbit but did not beat the Army to be the first. Their work in space continues today largely on military satellites.