The United Launch Alliance (ULA) will use its Delta IV Heavy rocket to launch the NROL-71 mission for the U.S. National Reconnaissance Office (NRO).
The launch was initially scheduled on Friday, Dec. 7, 2018 at 8:19 p.m. PST from the Space Launch Complex 6 of the Vandenberg Air Force Base in California.
Updated: 5:44 p.m. PST on Wednesday, Dec. 19, 2018.
This will be 132nd mission for United Launch Alliance and ULA’s second Delta IV Heavy launch in less than four months. It is the 382nd Delta launch since 1960, the 38th for a Delta IV rocket since 2002 and the 11th Delta IV Heavy.
NRO is the U.S. government agency which owns top secret spy satellites. Due to the classified nature of the NROL-71 mission, the details of the satellite, its purpose and its orbit are unknown.
Delta IV Heavy
The Delta IV Heavy is the America’s proven heavy lifter, delivering high-priority missions for the U.S. Air Force (USAF), National Reconnaissance Office (NRO) and NASA.
The Delta IV Heavy rocket stands 233 feet tall, is 53 feet wide and will weigh 1.6 million pounds once fully fueled. With its advanced upper stage, Delta IV Heavy can take more than 14,500 pounds directly to geosynchronous orbit, as well as a wide variety of complex interplanetary trajectories.
This Delta IV Heavy is comprised of three common core boosters each powered by an Aerojet Rocketdyne (AR) RS-68A liquid hydrogen/liquid oxygen engine, producing a combined total of more than 2.1 million pounds of thrust. The port and starboard boosters are more than 150 feet tall, and the center core with the interstage attached is over 175 feet in length. They measure 16.7 feet in diameter.
The Delta Cryogenic Second Stage, powered by an Aerojet Rocketdyne RL10B-2 liquid hydrogen/liquid oxygen engine producing 24,750 pounds of thrust , puts the vehicle into a preliminary orbit, then fires a second time to achieve an Earth-escape trajectory. The powerplant features a deployable carbon-carbon nozzle that is 7 feet in diameter.