The U.S. Air Force’s Advanced Extremely High Frequency protected communications satellite system is now being used by three U.S. allies following the United Kingdom’s successful linkup, AEHF prime contractor Lockheed Martin announced June 10.

The U.K. armed forces connected to the AEHF-2 satellite starting in February using a ground terminal and a terminal designed for ships at sea. By April, the U.K. was participating in U.S.-led AEHF tests that also included Canada and the Netherlands, both of which made their first secure calls through the system in 2013.

The first satellite in the constellation, AEHF-1, was launched in August 2010 but took more than a year to reach its operational orbit due to a propulsion glitch. AEHF-2 joined AEHF-1 in orbit in May 2012. AEHF-3 launched in September.

The satellites, built by Lockheed Martin Space Systems of Sunnyvale, California, are designed to provide assured and highly secure communications links under all conditions, including a nuclear war. One AEHF satellite provides more capacity than the entire legacy Milstar constellation. 

“AEHF not only delivers higher-bandwidth communications for the U.K., it makes communications with allies faster and easier,” Mark Calassa, Lockheed Martin’s vice president of Protected Communication Systems, said in the release.