The launch of a United Launch Alliance (ULA) Delta IV Heavy rocket on 26 April was conducted on behalf of the U.S. National Reconnaissance Office (NRO) and carried a national security payload, designated NROL-82. It departed from Space Launch Complex-6 (SLC-6 know as “Slick Six”), part of Vandenberg Air Force Base in California.
The Delta IV Heavy is used by the U.S. Space Force as well as the NRO and NASA to launch high-priority missions. It is the largest of the Delta IV family with the three rocket boosters mounted together to form a triple-body rocket. This Heavy configuration has now been used 31 times.
“The unmatched power of the Delta IV Heavy again demonstrated its role as the nation’s proven heavy lift vehicle precisely delivering this critical NRO asset to its intended orbit,” said Gary Wentz, ULA vice president of Government and Commercial Programs.
The Delta IV Heavy comprised 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 second stage was powered by an AR RL10B-2 liquid hydrogen/liquid oxygen engine.
ULA’s next launch is the Space Based Infrared System (SBIRS) GEO Flight 5 mission for the U.S. Space Force, scheduled for 17 May, 2021, from Cape Canaveral Space Force Station, Florida. To date ULA has launched 143 times with a reported 100 percent mission success.
Northrop Grumman Corporation provides key components to the ULA Delta IV Heavy rocket. These include three thermal shields that house and protect the engines during flight; three centerbody structures that connect the liquid oxygen (LOX) and liquid hydrogen (LH2) tanks; the payload fairing that provides protection to the payload; the composite interstage on the center common booster core; the nose cones on the two strap-on boosters and one set of X-panel structures that connect the upper stage LOX tank with the upper stage hydrogen tank.