United Launch Alliance launched its last classified U.S. military payload into orbit on Tuesday aboard an Atlas V rocket, ending the Pentagon’s use of Russian-made rocket engines as it transitions to all American-made launch vehicles for national security missions.
The Atlas V rocket lifted off from Cape Canaveral, Florida, at 6:45 a.m. EDT (10:45 UTC) Tuesday, powered by a Russian-made RD-180 engine and five strap-on solid-fuel boosters in its most powerful configuration. It was the 101st launch of the Atlas V rocket since its debut in 2002, and the 58th and final Atlas V mission carrying a U.S. national security payload since 2007.
The U.S. Space Force Space Systems Command confirmed the successful completion of the mission codenamed USSF-51 on Tuesday afternoon. The rocket’s Centaur upper stage released its top-secret USSF-51 payload from a high-altitude geostationary orbit above the equator about seven hours after liftoff. The military did not release the exact specifications for the rocket’s target orbit.
“It was truly a fantastic launch and a fitting conclusion to our last national security space Atlas V launch,” Walt Lauderdale, USSF-51 mission manager for Space Systems Command, said in a post-launch press release. “When we look back at how well Atlas V has met our needs since its inaugural launch in 2007, it speaks volumes about the hard work and dedication of our nation’s industrial base. We did it together, and because of these teams, we have the most successful and prosperous launch industry in the world. By far.”
The Long Farewell to RD-180
Tuesday morning’s launch marked the end of an era in which U.S. government policy in the 1990s allowed the Atlas V’s original developer, Lockheed Martin, to use a Russian rocket engine in its first stage. In the first decade after the collapse of the Soviet Union, there was widespread public opinion that the U.S. and other Western countries should work with Russia to hire its aerospace workers and prevent “rogue states” like Iran and North Korea from hiring them.
At the time, the Department of Defense was procuring new rockets to replace older versions of the Atlas, Delta, and Titan rocket families that had been in service since the late 1950s or early 1960s.
The Air Force ultimately chose Lockheed Martin’s Atlas V and Boeing’s Delta IV rockets for development in 1998. The Atlas V, with its Russian main engine, was somewhat cheaper than the Delta IV and was the more successful of the two designs. After Tuesday’s launch, 15 Atlas V rockets were scheduled to fly payloads for commercial customers and NASA, primarily for Amazon’s Kuiper network and Boeing’s Starliner crew spacecraft. The 45th and final Delta IV launch took place in April.
Boeing and Lockheed Martin merged their rocket businesses in 2006 to form a 50-50 joint venture called United Launch Alliance, which became the only contractor qualified to carry large U.S. military satellites into orbit until SpaceX began its national security mission in 2018.
SpaceX filed the lawsuit challenging the Air Force’s decision in 2014 to award ULA a multibillion-dollar single-source contract for 36 Atlas V and Delta IV rocket booster cores. The lawsuit was filed shortly after Russia’s military occupation and annexation of Crimea, which led to the U.S. imposing sanctions on prominent Russian government officials, including Dmitry Rogozin, then Russia’s Deputy Prime Minister and later the head of the Russian space agency.
Rogozin, known for his aggressive but usually tactical rhetoric, threatened to halt exports of RD-180 engines for U.S. military missions on the Atlas V. This did not happen until 2022, when Russia finally halted engine exports to the U.S. after its full-scale invasion of Ukraine. At that point, ULA already had all the engines it needed to fly its remaining Atlas V rockets. The ban had a bigger impact on Northrop Grumman’s Antares rockets, which used Russian engines, forcing them to develop an entirely new first-stage booster using American engines.
The SpaceX lawsuit, Russia’s initial military invasion of Ukraine in 2014, and the resulting sanctions were the beginning of the end for the Atlas V rocket and ULA’s use of the Russian RD-180 engine. Built by a Russian company called NPO Energomash, the dual-nozzle RD-180 burns kerosene and liquid oxygen propellants and produces 860,000 pounds of thrust at full throttle.
