The U.S. Air Force has accepted an SBIRS Highly Elliptical Orbit (HEO) system from prime contractor Lockheed Martin, the Company announced Nov. 13. The SBIRS payload and ground system, built by Lockheed Martin, is designed to provide early warning of missile launches, and support other missions such as missile defense, technical intelligence, and battlespace awareness. Northrop Grumman is the payload integrator. Acceptance paves the way for the U.S. Strategic Command's formal certification of the HEO-1 system in December. Lockheed Martin's current SBIRS contract includes the two HEO payloads on orbit, two geostationary satellites, and ground-based assets to receive and process the infrared data.