Signal Credit - USAF Phillips Laboratory

The RKK Energia and Polyot PO teamed up with other industries to propose the Signal constellation of low earth orbit communications satellites. Up to 48 of these 310-kg spacecraft (12 satellites in each of four orbital planes) were to fly at altitudes of 1,500 km with inclinations of 74 degrees.

Launches would be conducted either by Kosmos-2 boosters with two spacecraft or by Tsyklon-3 boosters with six spacecraft. The long and narrow spacecraft would have a payload capacity of 70 kg and a design lifetime of six years. The design included UHF, L-band, and Ku- band transponders. Like several of its competitors, Signal suffered program delays, and the launch of the first prototype spacecraft slipped until at least 1995. It then slipped from sight.