TacSat-4: Military Utility in a Small Communication Satellite

TacSat-4 is a Navy-led joint mission to augment existing Satellite Communication (SATCOM) capabilities and to advance the state of Operationally Responsive Space (ORS) capabilities. In September 2011 TacSat-4 launched from Kodiak Launch Complex in Alaska into a low Highly Elliptical Orbit (HEO). During the following 12 months, experimentation and formal utility assessment were performed. This operational testing allowed users from across the Department of Defense and other governmental agencies to use the capability. The spacecraft and operations were sponsor by Office of Naval Research and Office of Secretary of Defense with Naval Research Lab leading the execution. The ORS Office funded launch and was tasked by the Commander of United States Strategic Command to conduct a Joint Military Utility Assessment (JMUA) to support a transition to operations decision as well as future acquisition decisions. This paper provides a description of the TacSat-4 system and a summary of the testing performed including the results. A primary objective of the TacSat-4 JMUA was to assess the use of small satellites to provide UHF SATCOM to support disadvantaged users in the tactical community. The TacSat-4 experimentation and JMUA activities performed to-date have shown TacSat-4’s ability to provide SATCOM for a wide range of users and applications, using standard SATCOM equipment. Voice, chat, file transfers and other network applications were successfully performed. In addition to providing new SATCOM, the TacSat-4 program also advanced many elements of the ORS concept such as maturing the ORS bus standards, developing an enhanced Minotaur-IV+ launch vehicle capability, demonstrating the first long dwell orbit and mission for a small satellite, and developing highly automated command and control and mission planning systems