By Emelie Rutherford
The Air Force’s first Advanced Extremely High Frequency (AEHF) military communications satellite could be at least seven months behind schedule in reaching its intended orbit after an engine shut down prematurely after a successful launch.
David Madden, the military satellite communications systems wing program director at the Air Force’s Space and Missile Systems Center, told reporters Aug. 30 that military and industry officials are crafting plans to send the satellite to its desired orbit next summer, instead of this fall.
The AEHF-1 satellite’s liquid-apogee engine stopped after failing to reach its expected acceleration twice, on Aug. 15 and Aug. 17, just days after the satellite was successfully launched into orbit aboard an Atlas V rocket on Aug. 14, he said. The Air Force had planned to boost AEHF-1 to a geosynchronous orbit (GEO) of more than 22,000 miles in November, which would have been three months after the launch. Now, Madden estimates it will take 10 to 12 months after the August launch, or seven to nine months behind schedule, to reach that desired GEO orbit.
After collecting data following the two aborted liquid-apogee engine burns, the Air Force believes the engine is unusable and does not plan to fire it again, Madden said.
“Currently we are following a rigorous and thorough mission assurance process,” he said on the conference call.
Four teams have been created–with officials from the Air Force, Lockheed Martin [LMT], and the Aerospace Corporation–that, among other things, will determine the root cause of the liquid-apogee engine problems and alternate ways to maneuver AEHF-1 to its desired orbit. The AEHFs uses other thrusters, including Hall Current Thruster.
“The Space and Missile Systems Center, in concert with (the Air Force Space Command’s headquarters), is following a rigorous and thorough mission assurance process to examine changes to the AEHF-1 planned orbit raising operations,” Madden said. “We have a credible plan to meet mission objectives, and we are now executing to that plan.”
Prime contractor Lockheed Martin has built three AEHF satellites and is awaiting a contract for a fourth later this year.
The AEHFs are intended to replace the Milstar military communications satellites.