Industry firms combine technologies for first AEHF mission

CAPE CANAVERAL AIR FORCE STATION, Fla., 16 Aug. 2010. A United Launch Alliance Atlas V rocket launched the Advanced Extremely High Frequency-1 (AEHF-1) satellite for the Air Force from Space Launch Complex- 41. The AEHF constellation of four satellites will provide 10 times greater capacity and channel data rates six times higher than that of the existing Milstar II communications satellites. AEHF-1 will be joined by the next two AEHF satellites to be launched during the next two years by ULA.

Posted by Courtney E. Howard

CAPE CANAVERAL AIR FORCE STATION, Fla., 16 Aug. 2010. A United Launch Alliance Atlas V rocket launched the Advanced Extremely High Frequency-1 (AEHF-1) satellite for the Air Force from Space Launch Complex- 41. The AEHF constellation of four satellites will provide 10 times greater capacity and channel data rates six times higher than that of the existing Milstar II communications satellites. AEHF-1 will be joined by the next two AEHF satellites to be launched during the next two years by ULA.

This launch marks the fifth mission overall and third Atlas V mission for ULA in 2010. AEHF-1 represents the latest "one-at-a-time" mission success which has been accomplished 43 times since ULA was formed on Dec. 1, 2006.

Jim Sponnick, ULA vice president, Mission Operations, comments: "This was a tremendous launch campaign highlighted by close teamwork between the U.S. Air Force, the ULA launch team and our many mission partners that made today's successful launch possible. We look forward to launching AEHF-2 in 2011."

This mission was launched aboard an Atlas V 531 launch vehicle configuration. The mission used an Atlas V common core booster powered by the RD AMROSS RD-180 engine, three Aerojet solid rocket motors, a Pratt & Whitney Rocketdyne RL10A upper stage engine, and a 5.4-meter diameter Ruag composite payload fairing.

ULA's next launch, currently scheduled for Sept. 20, is an Atlas V from Space Launch Complex-3 at Vandenberg Air Force Base, Calif. It is a National Reconnaissance Office mission in support of national defense.

ULA program management, engineering, test, and mission support functions are headquartered in Denver, Colo. Manufacturing, assembly, and integration operations are located at Decatur, Ala., Harlingen, Texas, San Diego, Calif., and Denver, Colo. Launch operations are located at Cape Canaveral Air Force Station, Fla., and Vandenberg Air Force Base, Calif.

The first Advanced Extremely High Frequency (AEHF) satellite was built by Lockheed Martin. The satellite is the most technologically advanced military communications satellite ever developed and will provide significantly improved global, survivable, highly secure, protected communications for warfighters operating on ground, sea and air platforms, says a representative.

"For over 15 years, the Milstar constellation has served as the backbone of secure military communications, helping the military operate in a secure mode without concern of enemy interference,” says Col. Michael Sarchet, commander of the Protected Satellite Communications Group at the U.S. Air Force's Space and Missile Systems Center. “AEHF will significantly enhance our national security space architecture, and we eagerly anticipate providing this new capability to the warfighter."

A single AEHF satellite will provide greater total capacity than the entire Milstar constellation currently on-orbit. Individual user data rates can be up to five times higher than Milstar's highest speed. The higher data rates will permit transmission of tactical military communications, such as higher-quality real-time video and faster access to battlefield maps and targeting data. In addition to its tactical mission, AEHF will also provide the critical survivable, protected, and endurable communications to the National Command Authority including presidential conferencing in all levels of conflict. The AEHF constellation will also serve international partners including Canada, the Netherlands and the United Kingdom.

"Our number one priority is delivering mission success for our customer," says Mike Davis, Lockheed Martin's AEHF vice president. "The AEHF system will vastly improve battlefield communications, delivering secure, real-time, connectivity to a greater number of forces in the field, and their commanders anywhere on the globe. We look forward to successfully executing the next steps necessary to making this national asset operational for the warfighter."

The AEHF team is led by the U.S. Air Force Military Satellite Communications Systems Wing at the Space and Missile Systems Center, Los Angeles Air Force Base, Calif. Lockheed Martin Space Systems Company, Sunnyvale, Calif., is the AEHF prime contractor, space and ground segments provider as well as system integrator, with Northrop Grumman Aerospace Systems, Redondo Beach, Calif., as the payload provider.

Pratt & Whitney Rocketdyne helped boost into orbit the military communications satellite. The Atlas V is powered by the RD AMROSS RD-180 booster engine and a Pratt & Whitney Rocketdyne RL10 upper-stage engine. Pratt & Whitney Rocketdyne is a unit of United Technologies Corp. RD AMROSS LLC is a joint venture of Pratt & Whitney Rocketdyne and NPO Energomash.

The Atlas V Centaur upper stage is powered by a single RL10A-4-2 engine that delivers 22,300 pounds of thrust. The Atlas V Common Core booster is powered by the RD-180 engine delivering nearly 1 million pounds of thrust. The RD-180 is the only liquid oxygen-kerosene fueled engine with an oxygen-rich staged combustion cycle flying in the United States today, according to a company representative.

Aerojet, a GenCorp company, announced its role in the launch: the company provided three solid rocket boosters for the Atlas V launch vehicle, eight retro rockets for the Atlas Centaur separation from the launch vehicle, 12 reaction control thrusters for the Centaur upper stage, as well as the high-power electric and monopropellant propulsion for the inaugural AEHF space vehicle.

Aerojet's solid rocket boosters (SRB) on the Atlas V vehicle are 67-feet long and provide an average of 250,000 pounds of thrust. Aerojet SRBs have flown in previous vehicle configurations using one, two, three, and five boosters.

Eight Aerojet retro rockets assisted with the Atlas Centaur separation from the launch vehicle. In addition, 12 Aerojet monopropellant (hydrazine) thrusters on the Atlas V Centaur upper stage provided roll, pitch, and yaw control as well as settling burns for the upper stage main engine.

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