credit: Ursa Major

Ursa Major achieves a milestone with the successful hotfire test of the Draper, a liquid engine that the company claims has “the storability of a solid motor.” The Colorado-based expert in rocket motors made with additive manufacturing (AM) started the development of this engine in May 2023.

The 4,000-pound-thrust closed catalyst cycle engine (1814 kg) uses a non-cryogenic fuel that optimizes storability, making the engine uniquely suited for in-space propulsion applications. Based on its thrust profile, the engine is not only capable of maneuvering objects in orbit but doing so without fully depleting its store of propellant, potentially allowing for additional mission functions. As adversaries like Russia and China pursue anti-satellite systems, the need for defensive technology will continue to grow – Ursa Major’s Draper propulsion system is primed to be a part of that response.

The development and testing of Draper are supported by funding from a contract with the Air Force Research Laboratory (AFRL).

Perhaps the most-impressive aspect of this program is the delivery of a versatile, storable rocket engine in such an incredibly short timeframe. AFRL and industry is taking on the challenge our USAF and USSF leadership has asked of us…to deliver faster capabilities, craft tighter bonds with industry, and leverage what is already in existence to provide asymmetric advances. And thankfully, this is just the tip of the iceberg when it comes to what we are doing as One Team,” said Dr. Shawn Phillips, Chief of AFRL’s Rocket Propulsion Division.

Drawing on the architectural and manufacturing legacy of Ursa Major’s Hadley engine, Draper combines the storable attributes of a solid rocket motor with active throttle control and throttle range of a liquid engine, providing the maneuverability and flexibility that is needed for hypersonic defense. It is this unique design that allows the engine to effectively simulate hypersonic threats and that makes the engine well-equipped to address the critical gap in America’s hypersonics capabilities.

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