Fleet Satellite Communications System

The solar array of each satellite had a span of over 13.2 m. A special characteristic was a UHF transmit antenna reflector 4.9 m in diameter.

Additionally FLTSATCOM 7 and 8 included an experimental EHF transponder built by Lincoln Laboratory intended to test the MILSTAR ground terminals.

The fifth satellite reached geosynchronous orbit, but had severely limited utility due to damage to the solar arrays and antennas.

51 seconds into the flight, the Atlas was struck by lightning and the resulting EMP changed a value in the guidance computer's core memory, causing the rocket to yaw and break apart from aerodynamic stress.

As a result of this mishap, NASA and the Air Force re-emphasised and clarified the original weather guidelines developed after the Apollo 12 on-stand lightning strike for all future launches.