The U.S. Air Force and its mission partners successfully launched the third and fourth Orbital ATK built Geosynchronous Space Situational Awareness Program (GSSAP) satellites aboard a United Launch Alliance Delta IV launch vehicle from Space Launch Complex 37, Cape Canaveral AFS, Florida at 12:52 a.m. EDT.

This latest launch will enhance our capabilities in space situational awareness and our space-based space situational awareness architecture," said Lt. Gen. Samuel Greaves, SMC commander and Air Force program executive officer for space. "We will continue our unwavering focus on mission success and guaranteeing assured access to space for our nation. Congratulations to the AFSPC-6 integrated team and all mission partners on a successful launch."

The satellites join a GSSAP constellation currently supporting U.S. Strategic Command space surveillance operations as a dedicated Space Surveillance Network sensor. The GSSAP also supports the Joint Functional Component Commander for Space by collecting space situational awareness data, allowing for more accurate tracking and characterization of man-made orbiting objects.

SMC and its mission partners conducted the mission launch aboard a Delta IV Medium-plus configuration Evolved Expendable Launch Vehicle. The EELV program was established by the United States Air Force to provide assured access to space for Department of Defense and other government payloads. The commercially developed EELV program supports the full range of government mission requirements, while delivering on schedule and providing significant cost savings over the heritage launch systems.

Air Force Space Command's Space and Missile Systems Center, located at Los Angeles Air Force Base, California, is the U.S. Air Force's center of acquisition excellence for acquiring and developing military space systems.

Its portfolio includes the Global Positioning System, military satellite communications, defense meteorological satellites, space launch and range systems, satellite control networks, space based infrared systems and space situational awareness capabilities.

Aerojet Rocketdyne Supports Launch of AFSPC-6 Mission
Aerojet Rocketdyne supported the launch of two Geosynchronous Space Situational Awareness Program (GSSAP) satellites into orbit to help detect and track space objects as part of the Air Force Space Command-6 (AFSPC-6) mission.

The mission was launched from Cape Canaveral Air Force Station in Florida by a United Launch Alliance Delta IV rocket. Aerojet Rocketdyne propulsion included an RS-68A booster engine and an RL10B-2 upper-stage engine, 12 helium pressurant tanks and 12 reaction control thrusters on the upper stage for roll, pitch, yaw and settling burns.

"In today's world, it's absolutely critical that our nation have the ability to monitor potential threats to military satellites operating in geosynchronous orbit above our planet," said Aerojet Rocketdyne CEO and President Eileen Drake. "We are honored to provide reliable propulsion to make that possible."

At liftoff, a single RS-68A engine ignited to boost the Delta IV rocket off the pad, providing 702,000 pounds of lift-off thrust. The RS-68A is the world's most powerful liquid-hydrogen/liquid-oxygen engine; its family of engines has now flown 33 commercial and government missions with 100 percent mission success. After the upper stage separated from the launch vehicle, a single RL10B-2 engine ignited to provide 24,750 pounds of thrust to power the upper stage, using cryogenic liquid hydrogen and liquid oxygen propellants during its operation.

The RL10B-2 engine is a liquid-fueled cryogenic rocket engine designed and developed from the RL10 family of upper-stage engines, which has accumulated one of the most impressive lists of accomplishments in the history of space propulsion. More than 470 RL10 engines have supported launches over the last 50 years, helping to place military, government and commercial satellites into orbit, and powering scientific space-probe missions to every planet in our solar system.

Twelve 9-lbf MR-106H Aerojet Rocketdyne monopropellant hydrazine thrusters packaged in four 3-engine MRM-106F modules on the Delta IV upper-stage provided roll, pitch and yaw control, as well as settling burns for the upper-stage. ARDE, a subsidiary of Aerojet Rocketdyne based in New Jersey, provided the pressure vessels on the first and second stages on the launch vehicle.

The twin spacecraft are the third and fourth satellites for the GSSAP. They will support U.S. Strategic Command space surveillance operations as a dedicated Space Surveillance Network sensor. The GSSAP also supports Joint Functional Component Command for Space tasking to collect space situational awareness data, allowing for more accurate tracking and characterization of man-made orbiting objects.