by Marina Malenic

Orbit-raising activities for the first Advanced Extremely High Frequency communications satellite (AEHF-1) are going according to plan, according to Air Force officials.

Shortly after the launch last August, the plan was modified as a result of an anomaly with the bi-propellant propulsion system, which was intended to place the spacecraft near its operational orbit (Defense Daily, Aug. 31, 2010). The new plan entails two phases: one phase using hydrazine thrusters, which is now complete; and the other using the Hall Current Thruster (HCT) electrical propulsion system.

The HCT electrical propulsion system has achieved more than 1,400 hours of successful operation and raised the satellite’s perigee to more than 13,350 km altitude, the Air Force said in a press statement released yesterday.

The satellite is safe, according to Air Force officials, and continues to operate as planned. It is still expected to reach geosynchronous orbit late this summer.

AEHF is designed to provide the military and other government officials with protected, high capacity, high speed communications. It is the successor to Milstar.

AEHF-1 will join five legacy satellites that make up the Milstar constellation and will provide more communications capacity than all five of those vehicles combined, according to Air Force officials (Defense Daily, Aug. 4). The AEHF constellation of at least four satellites is eventually expected to provide 10 times the total Milstar capacity, as well as data rates at least five times faster.

Canada, the Netherlands and the United Kingdom have participated in the development effort and will receive new capability once AEHF-1 is online, Air Force officials have said.

Prime contractor Lockheed Martin [LMT] late last year received a cost-plus-incentive-fee contract modification valued at approximately $1.4 billion for production of the fourth AEHF space vehicle (Defense Daily, Dec. 10, 2010).

Meanwhile, AEHF-2 has completed production and is in storage until its scheduled launch in 2012. AEHF-3 is undergoing Thermal-Vacuum Testing and is on track to complete production later this year.