Lockheed said Tuesday that the Space Based Infrared System is intended to have a mix of company-built Geosynchronous Earth Orbit satellites, hosted payloads in a highly elliptical orbit and ground-based hardware and software.
SBIRS is being built for the president, defense secretary, intelligence and military leaders to receive missile warning and infrared surveillance information and to help warfighters acquire situational awareness in the field.
Air Force Space Command gave operational acceptance to GEO satellites one and two in 2013 and the third satellite is undergoing acoustic and thermal vacuum testing ahead of a scheduled delivery later this year, the company said.
GEO satellite number four is in the final assembly, integration and test phase.