The Air Force has extended Lockheed Martin‘s [LMT] engineering support contract for the Advanced Extremely High Frequency (AEHF) satellite program.

The $312 million contract modification that runs through the end of 2014 calls on Lockheed Martin to provide in-orbit anomaly resolution and investigation, flight and payload software sustainment, mission control familiarization and developmental testing.

AEHF is the follow-on program to Milstar, which is a five-satellite constellation communications system.

AEHF is designed to provide survivable, global, protect and jam resistant communications for ground, sea and air assets. The joint program is run by the Air Force and also supports special operations, strategic nuclear operations, missile defense and space operations and intelligence.

AEHF consists of four satellites, the first of which was launched in August 2010 and is undergoing in orbit testing ahead of becoming operational, which is scheduled for early next year.

The second AEFH is set for launch in April 2012, with the third to follow in late 2012 and the fourth in 2017.

The Air Force Space and Missile Systems Center in Los Angeles oversees the program.

The Air Force in December 2010 awarded Lockheed Martin a $1.4 billion contract to build the fourth bird.

The Air Force bills AEHF as being 10 times more capable than Milstar.

Raytheon [RTN] said in November that it has its first successful hook-up of its Army Secure Mobile Anti-jam Reliable Tactical Terminal (SMART-T) with AEHF during the ongoing tests. Raytheon is pegged to deliver 364 AEHF SMART-T terminals to the Pentagon.