Polar Bear

Polar Bear (Polar Beacon and Research), also known as STP P87-1, was a military mission designed to study communications interference caused by solar flares and increased auroral activity. It was to continuie the mission of its predecessor, HILAT. The spacecraft was built on the Transit-O 17 navigational satellite that was retrieved from the Smithsonian's National Air & Space Museum, where it had been on display for 8 years. Polar bear was gravity gradient stabilized by deployable boom with tip mass and was powered by 4 small deployable solar arrays.