Colorado-based aerospace and defense contractor Ursa Major has announced the first successful “hot fire” test of its Draper liquid-fuel engine. Funded by the Air Force Research Labs (AFRL), Ursa Major debuted the 4,000-lb thrust closed-cycle engine in May 2023, with the ultimate goal of having a fully operational engine capable of operating in the atmosphere or in space by the end of 2024.
According to a statement from the company, this successful test launch in May puts Draper’s development ahead of schedule and “exceeding industry standards.”
“We are excited by the pace at which the development program has progressed and look forward to deploying the engine for hypersonic and space applications in the coming years,” said Brad Appel, Chief Technology Officer at Ursa Major.
Non-cryogenic fuel makes Draper ideal for hypersonic and space applications
In the company statement, Draper engine developers said the ability to create a powerful thrust profile without the use of cryogenic fuels offers aerospace engineers unprecedented versatility. Fuels that don’t need to be stored at subzero temperatures save significant space compared to liquid oxygen engines, resulting in the ability to carry significantly more fuel into space.
“Based on its thrust profile, the engine is not only capable of maneuvering objects into orbit, but can also do so without completely depleting its fuel supply, potentially enabling additional mission capabilities,” the company explained.
According to Ursa Major, that level of versatility is increasingly important as enemy nations develop a myriad of weapons platforms designed to disable or destroy U.S. space assets. As this space race continues, the company says, “the need for defensive technology will continue to grow.” That means engines like Draper, which can launch spacecraft into space numerous times before running out of fuel, will become increasingly important in protecting those space assets.
In promotional materials for the engine in development, the company notes that Draper is an evolution of its production Hadley rocket engine. However, unlike Hadley, which is fueled by a combination of liquid oxygen and kerosene, Draper runs on a combination of hydrogen peroxide and kerosene. According to the company, this change means that Draper “combines the storage properties of a solid rocket motor with the active throttle control and throttle range of a liquid motor.” This combination, they explain, also gives Draper “the maneuverability and flexibility needed for hypersonic defense.”
Air Force Research Labs touts engine power and versatility
While Ursa Major has a number of engines in development, including the 50,000-pound thrust Ripley and the 200,000-pound thrust Arroway rocket, the Draper non-cryogenic liquid-fuel engine was specifically funded by the Air Force Research Labs. This funding included the design and construction of a specialized test stand at Ursa Major’s Berthoud, Colorado, test facility, where these test firings took place. According to the company, this specialized test stand “has and will continue to provide greater test capabilities and, in turn, faster iteration and development of the Draper engine.”
While there is no definitive schedule yet for Draper’s actual deployment, the AFRL says it has been impressed with the recent test flights and the rapid pace at which the engine has been developed over the past 12 months.
“Perhaps the most impressive aspect of this program is the delivery of a versatile, storable rocket motor in such an incredibly short time frame,” said Dr. Shawn Phillips, chief of AFRL’s Rocket Propulsion Division. “AFRL and industry are rising to the challenge that our USAF and USSF leadership has asked of us … to deliver faster capabilities, forge closer ties with industry and leverage what is already there to provide asymmetric progress.”
“Fortunately, this is just the tip of the iceberg in terms of what we do as one team,” added Dr. Phillips.
Christopher Plain is a science fiction and fantasy novelist and the chief science writer at The Debrief. Follow and connect with him on X, For more information about his books, visit plainfiction.com or email him at christopher@thedebrief.org.