Colorado-based aerospace and defense contractor Ursa Major has announced the first successful “hot fire” test of its Draper liquid propellant engine. Funded by Air Force Research Labs (AFRL), Ursa Major first demonstrated a 4,000 lb closed-cycle thrust engine in May 2023, with the ultimate goal of having a fully operational engine that can operate in the atmosphere or in space by the end of 2024.
According to a company statement, this successful test firing in May pushed Draper’s development ahead of schedule and “exceeded industry standards.”
“We are thrilled with how quickly the development program has progressed and look forward to deploying the engine for hypersonic and space applications in the coming years,” explained Brad Appel, Ursa Major’s Chief Technology Officer.
Non-cryogenic fuel makes Draper ideal for hypersonic and space applications
In a company statement, Draper engine developers say its ability to create a strong thrust profile without the use of cryogenic fuels offers spacecraft engineers unprecedented versatility. Fuels that do not need to be stored at sub-freezing temperatures save considerable 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 able to maneuver objects in orbit, but also without completely depleting the propellant supply, potentially enabling additional mission functions,” the company explains.
According to Ursa Major, this level of versatility is increasingly important as hostile countries develop numerous weapons platforms designed to disable or destroy US space facilities. As this space race progresses, the company says “the need for defense technology will continue to grow.” That means engines like the Draper, which can give spacecraft multiple shots into space before running out of fuel, will become increasingly important to protecting these space facilities.
In promotional material for the engine under development, the company states that the Draper is an evolution of their production Hadley rocket engine. However, unlike the Hadley, which is powered by a combination of liquid oxygen and kerosene, the Draper runs on a combination of hydrogen peroxide and kerosene. According to the company, this change means the Draper “combines the storable attributes 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 that is needed for hypersonic defense.”
Air Force Research Laboratories offer engine performance and versatility
While Ursa Major has a number of engines under development, including the 50,000 lb thrust Ripley and the 200,000 lb thrust Arroway heavy lift rocket, the Draper non-cryogenic liquid propellant engine was specially funded by the Air Force Research Laboratories. This funding included the design and construction of a dedicated test stand at Ursa Major’s Berthoud Test Facility in Colorado, where this test firing took place. According to the company, this dedicated test bench “has and will continue to enable greater testing capabilities and, consequently, faster iteration and development of the Draper engine.”
While there is no definitive timeline for real-world deployment of the Draper, the AFRL says it is impressed with the recent test launch and the rapid pace of engine development over the past twelve months.
“Perhaps the most impressive aspect of this program is the delivery of a versatile, storable rocket engine in such an incredibly short time frame,” said Dr. Shawn Phillips, AFRL Rocket Propulsion Division Chief. “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 already exists to deliver asymmetric advances.”
“Fortunately, this is only the tip of the iceberg in terms of what we do as a team,” added Dr. Phillips.
Christopher Plain is a science fiction and fantasy writer and senior science writer at The Debrief. Follow him and connect with him X, learn about his books at plainfiction.com or email him directly at christopher@thedebrief.org.