Colorado-based Ursa Major is developing its reusable Arroway 200,000-pound thrust liquid oxygen and methane staged combustion engine for military and commercial use.

The development comes as the Department of the Air Force weans itself off of Russian RD-180 and RD-181 engines. In March, Dmitry Rogozin, head of the Russian state space agency Roscosmos, said that Russia would stop selling the engines to the United States because of U.S. sanctions against Russia for the latter’s assault on Ukraine.

Arroway is to undergo hot-fire testing next year and be available for delivery in 2025. Ursa Major’s other engines include “Hadley,” a 5,000-pound thrust, oxygen-rich staged combustion engine, and the 50,000-pound thrust “Ripley” engine.

“Arroway is America’s engine of the future,” said Ursa Major CEO Joe Laurienti, a University of Southern California aerospace engineering graduate and former SpaceX and Blue Origin employee who founded Ursa Major as a 28-year-old in 2015.

“Medium and heavy launch capacity is what U.S. launchers desperately need right now, and because Ursa Major focuses solely on propulsion, we’re in a unique position to deliver high-performing, reliable, and affordable engines to meet the increasing market demand, just like we are doing with ‘Hadley’ and ‘Ripley,'” Laurenti said in a June 2 statement.

In August 2020, United Launch Alliance (ULA)–a Boeing [BA]-Lockheed Martin [LMT] partnership–and SpaceX beat out Northrop Grumman [NOC] and Blue Origin for the second phase of the National Security Space Launch (NSSL) program (Defense Daily, August 7, 2020).

Despite the loss, Blue Origin retains a stake in NSSL, as the company’s BE-4 engine is to power ULA’s Vulcan Centaur rockets for NSSL. Last August, Air Force Secretary Frank Kendall expressed concern about BE-4 development delays (Defense Daily, Aug. 27, 2021).

SpaceX’s Merlin engines power the company’s Falcon rockets, while Aerojet Rocketdyne‘s [AJRD] RS-68 engines have powered ULA’s Delta IV heavy launch vehicle, and the Russian RD-180 has lifted ULA’s Atlas V rocket.

“Notably, Arroway engines will be one of very few commercially available engines that, when clustered together, can displace the Russian-made RD-180 and RD-181, which are no longer available to U.S. launch companies,’ Ursa Major said on June 2.

The company also said that 3D printing can help build most of the Arroway engine.

Ursa Major said that 3D printing “allows for rapid iteration during the development process as well as efficient scaling of production to meet market demand.”

The company has said that its advisers include former Air Force acquisition chief Will Roper, former DoD Undersecretary of Defense for Policy Michele Flournoy, former Air Force Secretary Deborah Lee James, former Northrop Grumman CEO Ron Sugar, and former NASA Administrator Charles Bolden.