Rocket propulsion innovator Ursa Major is rapidly advancing development and testing of its Draper liquid rocket engine, collaborating closely with U.S. defense agencies and contractors. The primary objective is to integrate the engine into cutting-edge missiles within the Trump administration's Iron Dome missile-defense system.
Following successful ground tests funded by the U.S. Air Force at their Berthoud, Colorado facility, Ursa Major is initiating a comprehensive flight-testing program. This phase aims to refine the engine's design, explore military applications, and assess its viability for commercial ventures such as space tugs and in-space transportation. “We believe Draper fills a gap that the United States has in its armaments and targets,” stated Christopher Spagnoletti, Ursa Major's chief product officer.
The Pentagon's pursuit of an advanced missile defense system underscores the critical need for enhanced propulsion technology. The Iron Dome necessitates high-performance interceptor missiles capable of ground or space-based deployment, according to Spagnoletti. He highlighted the challenges many existing propulsion systems face in balancing the size, weight, and performance requirements of tactical missiles. The Draper engine provides a liquid-propulsion solution, offering greater flexibility than traditional solid rocket motors and air-breathing scramjets. “Draper has the form factor of a solid rocket motor,” Spagnoletti explained to SpaceNews.
Its unique kerosene peroxide fuel blend simplifies storage compared to systems using liquid oxygen. The propellants remain liquid at room temperature, negating the need for complex cooling systems, ensuring long-term storage without specialized equipment and enabling immediate operational readiness.
The Pentagon’s Iron Dome initiative envisions deploying numerous space-based interceptors for boost-phase intercept. This involves positioning a significant number of weapons in Earth orbit to neutralize incoming missiles during their initial, engine-burning phase. The 4,000-pound-thrust Draper engine is well-suited for space-based interceptors due to its adaptability to both atmospheric and in-space propulsion, Spagnoletti noted. Current missile defense systems primarily rely on solid rocket motors for efficient storage and swift deployment, while hypersonic weapons often utilize scramjets. In contrast, Draper operates effectively across various environments.
A 2023 Congressional Budget Office report highlighted propulsion challenges in U.S. hypersonic missile development, emphasizing the difficulty of maintaining consistent engine performance throughout flight. Spagnoletti confirmed Ursa Major's collaboration with numerous defense agencies, including the Air Force Research Laboratory (a key development partner), the Army’s Space and Missile Defense Command (SMDC), and the Missile Defense Agency (MDA). Discussions are underway with major defense contractors, though specific partnerships remain undisclosed. Hypersonic glide vehicles, capable of mid-flight maneuvering to strike moving targets, represent a potential application for Draper, demanding propulsion systems that withstand extreme conditions while delivering sustained thrust. “We’ve spent a lot of time with SMDC and MDA, focusing on very specific targets and hypersonic targets,” Spagnoletti said.
Successful flight tests would shift the focus to scaling production, a process requiring substantial government backing. While numerous startups are addressing the Pentagon's need for innovative propulsion technologies, scaling manufacturing presents a significant challenge. Spagnoletti believes the Iron Dome executive order could significantly alter priorities within the defense industrial base. “There’s been a lot of increased activity, and we expect this to continue,” he noted. Defense agencies are actively working to better assess their available resources and facilitate the transition of promising technologies from development to full-scale production. “That’s really the dividing line between a ‘great idea’ and the ability to scale these complex machines,” he concluded.