Rapid Advances Reported for Hadley H13 Engine
Latest Variant of the Ursa Major Liquid Rocket Engine
The latest variant of the production rate Ursa Major 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.
“With new materials and manufacturing, H13 can be reused more than twice as many times as previous variants.”
Chris Spagnoletti, Ursa Major
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.
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. The engine 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, the engine 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.