Sbirs GEO-1 Launches At Last

The first of a new generation of missile warning satellites has lifted off on it way to geosynchronous orbit. The Space-Based Infrared System (Sbirs) satellite, built by Lockheed Martin, boosted on an Atlas V 401 rocket at 2:10 p.m. EDT on May 7 from Cape Canaveral Air Force Station, Fla. The launch is a major achievement after the Air Force and Lockheed Martin struggled with myriad management and technical problems developing Sbirs. Eventually, the spacecraft will join existing Defense Support Program (DSP) satellites already in orbit to provide early warning of boosting ballistic missiles. Along with DSP, Sbirs will be among the first sensors to cue U.S. missile defenses in the event of a hostile launch. Sbirs GEO-1 is based on Lockheed Martin’s A2100 satellite bus and carries two payloads capable of collecting in the short- and mid-wave infrared (IR) bands, as well as one “wider, more open shortwave band” that can “see through to the ground,” Jeff Smith, Lockheed Martin Sbirs program manager told Aviation Week late last year. One of the payloads is a scanning IR detector. It is designed with shorter revisit times than those offered by DSP, which operates using a spinning scanner. Additionally, Sbirs GEO-1 will have a staring sensor that can focus on different geographical areas than the scanner. The Air Force currently hopes to buy six Sbirs satellites. Sbirs GEO-1 vehicle separation from the Atlas V’s Centaur upper stage took place 43 min. into the flight. At that point, the spacecraft was at 100 nm altitude heading for an apogee altitude of 19,323 nm. A series of six liquid apogee engine burns are planned over nine days to reach a geosynchronous orbit slot 22,000 mi. over the Earth for initial checkout and operations, says Lt. Col. Ryan Umstattd, an Air Force Sbirs official. At this point, the satellite will deploy its light shade (designed to protect the sensor payload), antennas and payload doors, he says. Thirty-five days after launch, officials expect to turn the IR payloads on and begin transmitting raw data from the satellite. Full integrated tactical warning and attack assessment certification, allowing the satellite to officially tip missile defenses in the event of a threat, is expected within 18 months of launch. Sbirs GEO-2 is likely to boost about one year after GEO-1. Already, two staring sensors in highly elliptical orbit — HEOs 1 and 2 — are providing infrared coverage of the extreme north regions.