Hypersonic Flight: Liquid Propulsion Enables Unmatched Maneuverability

Hypersonic Propulsion Revolution: How Storable Liquid Engines Close the U.S. Technology Gap

The United States faces a critical capability gap in hypersonic weapons development compared to Russia and China. Traditional propulsion methods—solid-fuel rockets and air-breathing engines like scramjets—each carry significant operational limitations that constrain speed, maneuverability, and deployment flexibility.

Ursa Major is addressing this challenge through storable liquid rocket engine technology that fundamentally changes what hypersonic systems can achieve. Unlike cryogenic liquid engines requiring specialized launch infrastructure, storable liquids can be loaded into weapons systems and stored for a decade or longer—aboard ships, aircraft, or forward operating bases—then deployed with the reliability of solid-fuel systems.

The company’s Draper engine, developed under the Air Force’s Angry Tortoise program, represents a breakthrough synthesis of capabilities. “It acts like a solid in that you press a button, and it starts,” explains Ursa Major CEO Dan Jablonsky. “But it also provides the additional flexibility of a liquid system, which is throttling, starting, stopping, and a higher level of maneuverability.” This control enables pilots to adjust trajectory mid-flight, enhancing both survivability and target engagement precision.

Critically, storable liquid engines operate across atmospheric and space environments where air-breathing systems fail. At extreme altitudes where oxygen density becomes insufficient for scramjets, Draper maintains full functionality. This dual-domain capability positions the technology as essential infrastructure for Space Force rapid-response missions and space-based missile defense initiatives.

Ursa Major’s manufacturing approach amplifies these advantages. The company uses advanced 3D printing to construct combustion chambers withstanding 5,000-6,000 degrees Fahrenheit and turbomachinery rotating at 50,000-60,000 RPM. Approximately 60% of the Draper engine is additively manufactured, enabling development iteration cycles measured in days rather than months. This manufacturing agility directly translates to faster capability deployment and lower production costs.

The Hadley engine, flown multiple times at Mach 5-plus speeds via Stratolaunch, demonstrated the technology’s maturity. For test and development purposes, vehicle recovery enables affordable creation of reusable threat simulators for radar calibration and air defense exercises.

With storable liquid propulsion, the U.S. can field hypersonic weapons matching peer-adversary range and speed while maintaining operational flexibility that previous systems couldn’t achieve. The convergence of liquid propulsion advantages, advanced manufacturing, and dual-domain capability positions Draper as a cornerstone technology for next-generation American warfighting.

Source ID: SRCE-2025-1764770686499-1112