Space Launch Hero

Space Superiority Starts Here

From liftoff to low Earth orbit, Ursa Major’s launch, satellite propulsion, and space-based defense systems move faster, fly farther, and adapt to the evolving threat landscape—delivering resilient space operations and true freedom to maneuver.

The Problem

Propulsion is notoriously difficult and expensive.

For decades, the U.S. aerospace and defense industry has faced two problematic choices for propulsion: build engines in-house—which can take 5-10 years and hundreds of millions of dollars—or buy outdated or foreign technology.

Propulsion accounts for
50%
Of launch failures
60%
Of vehicle costs
90%
Of vehicle complexity
The Approach

Get to the launch pad faster

With high-performing, turnkey rocket engines, Ursa Major focuses exclusively on propulsion so you don't have to.

80% of engines' mass is 3D printed for quick iteration, part commonality, and shorter build timelines​.
Oxygen-rich staged combustion cycle as our baseline is a higher performing architecture at a fraction of the cost of traditional engine programs.​​
80,000+ seconds of runtime in testing for proven reliability and performance.
Built with reusability in mind.
hadley wireframe mobile
hadley engine wireframe

Missions We Serve

In-space Maneuverability
Reliable propulsion capable of multiple restarts and a custom burn duration within the vacuum of space.
INSpace.png
Space-based Defense
Counter advanced threats from orbit, with propulsion designed for space-based interceptors.
hi7t58tc.png
Launch
Flexible engines for small, medium, and heavy launch vehicles.
Launch.png
Hadley

America’s first oxygen-rich staged combustion engine 


Suitable for small launch, hypersonics

Lox / Kerosene
Propellants
Oxygen-rich
staged combustion
5,000 lbf
Thrust, Sea Level
6,500 lbf
THRUST, VACUUM VARIANT
Ripley

Highest performing kerosene engine ever built in the U.S.


Suitable for small to medium commercial launch

Lox / Kerosene
Propellants
Oxygen-rich
staged combustion
50,000 lbf
Thrust, Sea Level
Arroway

The future of American engines for heavy lift


Suitable for medium to heavy launch, national security launch, RD-180 replacement

Lox / Methane
PROPELLANTS
Staged Combustion
200,000 lbf
Thrust, Sea Level
Draper

A flexible liquid engine with the storability of a solid motor


Suitable for tactical hypersonics, missile defense, in-space propulsion

Hydrogen Peroxide / Kerosene
Propellants
4,000 lbf
Thrust, Sea Level
Closed Catalyst Cycle
Latest News
Ursa Major Hadley Engine Flies for the First Time
Ursa Major's Hadley engine, a purpose-built engine to satisfy America's commercial and national security space needs, flew for the first time powering Stratolaunch's Talon-A1 (TA-1) testbed during a test over the Pacific Ocean. The test, which reached high supersonic speeds approaching Mach 5, marks the first step toward flight of a hypersonic vehicle developed by a private company.
Read More
hadley engine first flight