United Launch Alliance launched a secret National Reconnaissance Office spy satellite aboard a Delta 4 Heavy rocket from Space Launch Complex-37 (SLC-37) at the Space Force Station Cape Canaveral, Florida, on June 22 at 05:18 a.m. EDT. It was ULA’s second launch attempt, which was previously scheduled for June 21 but was delayed “due to a problem with the ground system pneumatic valve”, the company said.

About four minutes into flight, the triple-core Delta 4 Heavy’s external boosters disengaged. The second stage left after about two minutes. At NRO’s request, ULA ceased broadcasting approximately seven minutes before the flight, after the nose liner was removed. NROL-68 is the 15th and penultimate launch of the Delta 4 Heavy before its anticipated retirement. In 2022, the device made its last mission from the West Coast.

This mission was ULA’s first launch in 2023. In May 2019, the company received a US Air Force contract to launch NROL-68. The Delta 4 Heavy configuration was first released in December 2004. Each of the Delta 4 Heavy conventional boosters is powered by Aerojet Rocketdyone’s RS-68A main engines. The Delta cryogenic second stage is equipped with an RL10C-2-1 engine. The rocket uses liquid hydrogen and liquid oxygen at all stages.

ULA has a contract to launch another NRO satellite on a Delta 4 Heavy from Cape Canaveral in 2024. After that, ULA plans to decommission the Delta 4 Heavy and replace it with the new Vulcan Centaur rocket. Space Systems Command’s Atlas 5 and Delta 4 chief of staff, Lieutenant Colonel Scott Karstetter, stated that NROL-68 will be the first of four missions for ULA’s Atlas 5 and Delta 4 in the final year of Atlas/Delta operations. Source