Masten Achieves First Hot-Fire of Broadsword Rocket Engine

Broadsword 25 hot fire (Credit: Masten Space Systems)

MOJAVE, Calif. (Masten Space Systems PR) – On September 30, 2016, Masten Space Systems successfully concluded the 13-month design, build, and test period for the first development unit of the Broadsword 25 rocket engine, funded as a technology demonstration under the Defense Advanced Research Projects Agency (DARPA)’s Experimental Spaceplane (XS-1) program. This first phase of the engine development effort included commissioning Masten’s largest mobile engine test stand and firing of the company’s highest-thrust rocket engine to date.

The Broadsword 25 is a liquid oxygen- and liquid methane-propelled rocket engine with a full-throttle sea-level thrust rating of 25,000 lbf. Masten initiated development of the Broadsword in August 2015, as a cost-effective reusable engine suitable for use in both boost and upper-stage applications.

Broadsword employs a novel dual-expander cycle, which allows high efficiency at sea level while maintaining the benign turbomachinery conditions characteristic of traditional expander cycle engines. It is made primarily via additive manufacturing, or “3D printing”—a technology that enables complex design geometries, reduces part count by an order of magnitude, and compresses manufacturing times, all of which enable rapid engine development.

The goal of this initial hot-fire test campaign comprised ignition and startup sequence development. The effort concluded with demonstrating six successful engine starts. Masten has subsequently begun the design and build of a second development unit, incorporating lessons learned during manufacturing and testing, and plans to proceed with main-stage hot-fire testing in the next phase.

Masten aims to continue Broadsword development over the course of 2017 and 2018 in collaboration with NASA under the Tipping Point program, and anticipates moving into flight qualification after the conclusion of that effort.

For additional information regarding availability and pricing, please contact

For all other inquiries, please contact us via


  • It’s obvious now the military is interested in reusability and propulsion development.

    The SLS and Orion era are over. It sure took long enough.

  • Mr Snarky Answer

    The problem is the zombie (no Masten pun intended since isn’t xombie) rocket will probably continue long after is is obviously a bad idea just to serve it’s congressional masters.

  • That will be pretty funny to watch when rogue operators start clustering 25 lbf class 3D printed high performance methane engines and flying them regularly.

  • JamesG

    They should unchock the trailer and see how fast they can get it going. 😉

  • publiusr

    Stratolaunch is more of what they want. The space-warfighter wants to hide the plume from a vertical pop-up trajectory that would trigger alarms. Anyone can spy on a fixed pad, after all. This is why the Soviets so feared the B-52 lofted Skybolt.

  • Aerospike

    Armadillo Aerospace once drove their test truck down the runway under rocket power. It was only a few seconds, and it didn’t accelerate particularly fast (big truck, small rocket engine), but they really did it 😀

  • Now that you mention that a methane powered Stratolauncher vehicle was on my drawing table for a while, Structural costs of horizontal liquids seemed enormous.

  • patb2009 Darma formerly C&Space did a 20K Methane back in 2005…