Background image
Press Release

Ursa Major Rapidly Advances its Hadley H13 Engine

Hadley H13 is Ursa Major’s off-the-shelf liquid rocket engine designed for a variety of applications, including hypersonics and light launch

post-detail-img

BERTHOUD, Colorado, (March 4, 2026) — Ursa Major’s latest variant of the flight-proven, production rate Hadley liquid rocket engine, H13, has successfully completed its first hot fires, following a series of design improvements and updated manufacturing processes. Hadley H13 is the mission-upgraded variant of Ursa Major’s Hadley H11 engine, which is flight proven and designed for hypersonic applications. H13 increases engine reusability and improves overall engine performance compared to previous Hadley variants and is intentionally designed to fly in a variety of hypersonic and launch applications.

“Hadley is Ursa Major’s foundational engine that has already flown hypersonic several times,” said Chris Spagnoletti, CEO at Ursa Major. “With new materials and manufacturing, H13 can be reused more than twice as many times as previous variants, driving down the cost per flight while supporting new test objectives and mission profiles.”

The engine uses new materials to improve performance and increase engine life. By in-sourcing major components of the H13 engine, Ursa Major strategically implements vertical integration of additively manufactured parts, which ensures cost efficiency and streamlined manufacturing.

In the past, Hadley was a tailored solution, requiring bespoke development that resulted in longer lead times. H13 productizes the engine for diverse applications, including hypersonic flight and light launch, reducing lead times associated with engine development and positions Hadley as Ursa Major’s off-the-shelf liquid rocket engine for urgent hypersonic and launch needs. With its increased reusability and cryogenic fuels, H13 is the lowest cost-per-flight and highest performing engine Ursa Major has developed to date.

About Hadley

Hadley is a liquid rocket engine powering hypersonic and small launch missions, delivering 5,000 lbf of sea-level thrust, and up to 6,500 lbf in its vacuum variant. Hadley runs on liquid oxygen (LOX) and kerosene using an oxygen-rich staged combustion cycle for exceptional performance. Hadley is the first American-made propulsion engine of its kind to reach sustained Mach 5+ speeds and return, flying successfully with Stratolaunch’s Talon-A vehicle. Built with 80% additive manufacturing, Hadley enables rapid iteration, reduced part count, and accelerated production timelines. Hadley’s unprecedented innovation and success has set a new standard for agile, affordable propulsion in contested and commercial environments.

About Ursa Major 

Ursa Major is an aerospace and defense company delivering flight-proven capabilities for hypersonics, solid rocket motors, space mobility and launch. Headquartered in Berthoud, Colorado, with additive manufacturing operations in Youngstown, Ohio, Ursa Major leverages advanced production techniques and flexible architectures to build systems for all domains: land, air, sea, and space. The company is revitalizing the defense industrial base for the U.S. and its allies, flying faster to accelerate delivery of critical capabilities where speed and adaptability matter most. For more information, visit www.ursamajor.com.

For questions or to schedule an interview, please contact: [email protected]

Background Image