The payload for Lockheed Martin’s first Space-Based Infrared System (SBIRS) geosynchronous (GEO) spacecraft has completed thermal vacuum testing, the company announced July 23.

The test, performed by payload subcontractor Northrop Grumman, demonstrated the function and performance of the fully integrated GEO-1 payload in vacuum conditions and at temperatures expected when the satellite is on orbit. Northrop Grumman will prepare the payload for delivery to Lockheed Martin’s facilities in Sunnyvale, Calif., in early August for integration with the spacecraft.

SBIRS will provide early warning of ballistic missile launches and also support other missions, including missile defense, technical intelligence and battlespace characterization.

Lockheed Martin is under contract to provide two highly elliptical orbit payloads and two GEO satellites as well as the ground-based assets to receive and process the data.