Article

The US Air Force transitioned from the canceled Advent satellite program to develop the Initial Defense Satellite Communications System (IDSCS) in the early 1960s. The IDSCS utilized multiple medium-altitude satellites and aimed to enhance military communication capabilities.

The system was operational by 1968, featuring 35 satellites in near-synchronous orbits. It allowed for direct communication between military forces in Vietnam and Washington, DC. The IDSCS served as an interim solution, leading to the development of the larger Defense Satellite Communications System II (DSCS II) in the 1970s.