U.S. Navy Successfully Tests Advanced Solid Fuel Ramjet Missile from Unmanned Aircraft

In a remarkable leap for modern missile technology, the U.S. Navy has successfully tested an advanced Solid Fuel Integral Rocket Ramjet (SFIRR) propulsion system by launching it from an unmanned aerial vehicle for the very first time. This test, conducted by the Naval Air Warfare Center Weapons Division (NAWCWD), marks a significant milestone in the Navy’s mission to modernize its long-range strike capabilities and enhance the speed and reach of its future weapons.

The test was carried out using a BQM-34, an unmanned target drone modified to serve as the launch platform. What made this trial groundbreaking was the integration of a fire control system aboard the unmanned vehicle, enabling a live-fire scenario without risking any crew. This development proves the potential for engaging targets from greater distances with improved safety and operational flexibility.

What is a Solid Fuel Ramjet?

A Solid Fuel Ramjet is a type of missile propulsion system that uses solid fuel rather than liquid propellants. Unlike traditional rocket engines that burn all their fuel internally, a ramjet takes in air from the atmosphere during flight, mixing it with the fuel to maintain combustion and thrust. The advantage of this system lies in its simplicity and efficiency — eliminating the need for complex fuel tanks and pumps, reducing weight, and freeing up more space for payloads.

Key Specifications and Features of the SFIRR:

• Propulsion Type: Solid Fuel Integral Rocket Ramjet

• Fuel Type: Solid fuel grain integrated within the air duct

• Launch Platform: BQM-34 unmanned aerial vehicle

• Operational Benefits:

  • Higher sustained speeds at longer ranges

  • Simplified design with no liquid fuel handling

  • Greater missile payload capacity

  • Improved manoeuvrability during flight

  • Lower maintenance and better storage safety

Why This Test Matters

Though ramjet technology has been around for decades, this new test shows its continued importance in modern warfare. By refining older concepts with today’s advanced materials, avionics, and fire control systems, the Navy is creating faster, longer-range, and more reliable weapons suited for future combat environments.

Abbey Horning, Product Director at NAWCWD, emphasized that the rapid development of this demonstrator — completed within just 12 months — proves the Navy’s ability to quickly transition advanced research into operational technology. She stated, “This successful integration validates key aspects of our design and moves us closer to delivering an advanced propulsion system that will provide warfighters with greater range and speed.”

Modernizing for Future Conflicts

Ephraim Washburn, Deputy Director for Energetics at NAWCWD, compared the evolution of SFIRR technology to the continuous improvements made in the automotive industry. “We’ve been driving cars since the early 1900s, but that doesn’t mean we stopped improving them,” he remarked. The same principle applies to missile propulsion — what worked in the past is now being reengineered to meet the demands of contemporary battlefields.

What’s Next?

The insights from this successful test have already shaped the development of a next-generation missile prototype. Future efforts will focus on refining the system’s range, endurance, and targeting precision, ensuring the technology remains combat-credible and ready for fleet integration.

As the Navy works closely with government research agencies, defense contractors, and academic partners, advanced propulsion systems like the SFIRR are expected to play a vital role in keeping the U.S. Navy ahead in terms of speed, reach, and operational superiority.

This latest test is not just about revisiting an old idea — it’s about reimagining and upgrading it to tackle the complex, high-speed warfare scenarios of tomorrow.