United Launch Alliance (ULA) Successfully Launches NROL-91 Mission for National Reconnaissance Office (NRO).
United Launch Alliance Successfully Launches National Security Mission with Nation’s Proven Heavy Lift Vehicle.
Delta IV Heavy continues to deliver high priority missions in support of National Security.
VANDENBERG SPACE FORCE BASE, Calif., Sept. 24, 2022 – A United Launch Alliance (ULA) Delta IV Heavy rocket carrying the NROL-91 mission for the National Reconnaissance Office (NRO) lifted off on Sept. 24 at 3:25 p.m. PDT from Space Launch Complex-6 at Vandenberg Space Force Base. To date ULA has launched 153 times with 100 percent mission success.
“The NRO has been, and continues to be, a phenomenal partner through 32 collaborative launch campaigns, stemming from ULA’s very first launch in 2006,” said Gary Wentz, ULA vice president of Government and Commercial Programs. “This mission was ULA’s 96th National Security mission and the NRO’s 10th mission on board a Delta IV Heavy launch vehicle – a history that we are very proud of.”
“This was also ULA’s 95th Delta mission from Vandenberg Space Force Base and our fifth and final Delta IV Heavy from the West Coast, completing a long, successful tenure of delivering critical national security payloads,” added Wentz. “We look forward to preparing Space Launch Complex-3 for future Vulcan flights from the West Coast.”
ULA’s next launch is a commercial launch of the SES-20 and SES-21 mission, planned for Sept. 30 from Cape Canaveral Space Force Station, Florida.
Leveraging a legacy of 100 percent mission success launching more than 150 missions to explore, protect and enhance our world, ULA is the nation’s most experienced and reliable launch service provider with world-leading reliability, schedule confidence, and mission optimization. We deliver value unmatched by any launch services company in the industry, a tireless drive to improve, and commitment to the extraordinary.
Delta IV Launch System
The Delta IV launch system is available in three configurations: the Delta IV Medium+, with two or four solid rocket motors (SRMs), and the Delta IV Heavy. Each configuration is comprised of a common booster core (CBC), a cryogenic upper stage and a 5-meter-diameter payload fairing (PLF).
The Delta IV Heavy employs two additional CBCs as liquid rocket boosters to augment the first-stage CBC.
The payload fairing (PLF) provides a controlled, safe environment for spacecraft during ascent.
All ULA PLFs are configured for off-pad payload encapsulation, which enhances payload safety and security and minimizes on-pad time.
Delta IV offers a 5-meter-diameter PLF, optimized for the configuration and mission need. The Delta IV Medium uses a standard carbon composite bisector design. The Delta IV Heavy is available with an elongated carbon-composite bisector or metallic trisector PLF.
Design simplicity and demonstrated capability define the Delta IV RS-68A main engine. Designed and manufactured by Aerojet Rocketdyne, the throttleable RS-68A engine is the largest existing hydrogen-burning engine. Conceived using a simplified design approach, it has fewer parts, is lower risk and has inherently reliable operation.
Solid Rocket Motors
For additional thrust at liftoff, the Delta IV Medium+ uses either two or four Orbital ATK solid rocket motors (SRMs). The SRMs are strapped to the common booster core and jettisoned in-flight for maximum performance.
Both the Atlas V and the Delta IV rely on the RL10 propulsion system to power their second stages. Logging an impressive record of nearly 400 successful flights and nearly 700 firings in space, RL10 engines, manufactured by Aerojet Rocketdyne, harness the power of high-energy liquid hydrogen. The RL10 boasts a precision control system and restart capability to accurately place payloads into orbit.
The Delta IV employs the RL10B with the world’s largest carbon-carbon extendible nozzle for increased performance.