The first of a series of US Air Force Communication satellites built by Lockheed Martin has successfully concluded thermal vacuum testing.

The satellite, part of the Advanced Extremely High Frequency (AEHF) programme, will provide global secure, protective and survivable communications for all US warfighters, and international partners including Canada, the Netherlands and the UK.

The final thermal vacuum testing of the satellite, one of the several environmental test phases, validates the design, quality and survivability of the space vehicle during launch and on-orbit operations.

The satellite was stressed at extreme hot and cold temperatures during the tests to assess its performance and capabilites in preparation for its 14-year life in space.

After the environmental tests, final integrated spacecraft and system test activities will be performed by Lockheed, the primary contractor and Northrop Grumman, the payload supplier.

The second and the third satellites of the AEHF constellation are also moving through integration and test activities for launch in 2011 and 2012.

The satellite will be delivered to the air force in 2010 for launch atop an Atlas V vehicle.