SOLRAD 7B

SOLRAD 7B was the eighth solar X-Ray monitoring satellite in the SOLRAD series and the fifth to successfully orbit the Earth. It was launched via Thor Augmented Delta-Agena D along with seven other satellites on March 9, 1965. The satellite provided continuous coverage of the Sun during the International Quiet Solar Year from March through October 1965.

History

The SOLRAD science satellite program was conceived in 1958 to observe the Sun in the X-ray spectrum. It was quickly combined, to provide civilian cover (launches being unclassified at that time), with the concurrently conceived United States Naval Research Laboratory's GRAB satellite project, which would collect information on foreign radars and communications installations. There were five SOLRAD/GRAB missions between 1960 and 1962, with the scientific SOLRAD experiments sharing satellite space with GRAB's intelligence payload. Two of the missions were successful.

In 1962, all U.S. overhead reconnaissance projects were consolidated under the National Reconnaissance Office (NRO), which elected to continue and expand the GRAB mission starting July 1962 with a next-generation set of satellites, code-named POPPY. With the initiation of POPPY, SOLRAD experiments would no longer be carried on electronic spy satellites; rather, they would now get their own satellites, launched alongside POPPY missions to provide some measure of mission cover.

The first POPPY mission was launched on December 13, 1962, along with several other satellites on a mission similar to that of SOLRAD 3, complete with an Injun ionospheric research satellite. The mission was successful