The U.S. Air Force and Lockheed Martin Space Systems successfully completed thermal vacuum testing of the first Space Based Infrared System (SBIRS) satellite, clearing the way for launch in early 2011, according to a Dec. 1 Lockheed Martin press release.

The long-delayed SBIRS missile warning system will replace the Defense Support Program satellite constellation to provide early warning of missile launches around the world, as well as support the additional missions of missile defense, technical intelligence and battle space awareness. Sunnyvale, Calif.-based Lockheed Martin is the prime contractor for SBIRS, which is composed of dedicated geosynchronous satellites and payloads hosted on classified satellites in highly elliptical orbits.

Two of the highly elliptical orbiting payloads are now on orbit, but none of the geosynchronous satellites has been launched. The successful thermal vacuum testing showed the first SBIRS satellite can handle the dramatic temperature changes that it will experience in space and clears the way for it to be put through a series of “integrated spacecraft and system tests” at Lockheed Martin’s facilities, the release said. The company plans to ship the satellite to Cape Canaveral Air Force Station, Fla., in late 2010 in preparation for its launch on an Atlas 5 rocket.