WASHINGTON — Rocket propulsion startup Ursa Major announced April 24 that Astra Space selected the company’s Hadley liquid engine to power the upper stage of its new Rocket 4 launch vehicle.

Ursa Major is a Colorado-based manufacturer of liquid engines for small space launchers and hypersonic vehicles. The company said it is producing about 30 Hadley engines a year for the U.S. Air Force and several commercial customers, including small launcher startup Phantom Space and Stratolaunch.

“The Ursa Major-Astra partnership marks an important industry milestone in outsourcing propulsion to unlock growth and innovation for launch providers and their customers,” said Joe Laurienti, founder and CEO of Ursa Major. “We’re excited to be a part of Astra’s Launch System 2 and the company’s next chapter of success.”

Astra developing Rocket 4

Astra, a small satellite launch company based in Alameda, California, is developing the Rocket 4 vehicle after it discontinued a smaller version called Rocket 3.3. The company last week won a U.S. Space Force contract to launch experimental payloads.

Astra said it expects the first test flights for Rocket 4 to begin in late 2023.

Astra’s upper stage will use the vacuum variant of Hadley, an oxygen-rich staged combustion engine fueled by liquid kerosene. Ursa Major said the vacuum variant of Hadley provides 6,500 pounds of thrust, compared to Hadley’s sea-level configuration, which provides 5,000 pounds of thrust. 

Ursa Major last year won a U.S. Air Force $3.6 million contract to support the development and flight-qualification of the Hadley engine.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...