Possibly the First Detonation Rocket Flight

Venus Aerospace may have achieved a world first by successfully flying a Rotating Detonation Rocket Engine (RDRE) in the U.S.—a propulsion system that uses supersonic explosions and could power future hypersonic vehicles.

On May 14, 2025, Venus Aerospace conducted a test flight at Spaceport America near White Sands Missile Range, New Mexico, which may mark the first atmospheric flight of a Rotating Detonation Rocket Engine (RDRE). While Japan’s space agency JAXA tested similar engines on sounding rockets in 2021 and 2024, those were space-bound missions, whereas the U.S. test involved the RDRE actively powering flight within Earth’s atmosphere.

Venus Aerospace Eyes Mach 6 with Combined RDRE/Ramjet Engine

This latest RDRE test supports the company’s goal of developing a hypersonic vehicle that can reach speeds up to Mach 6, powered by a combined RDRE/ramjet engine designed for seamless operation from takeoff to cruise to landing.

A crucial component is Venus Aerospace’s VDR2, an air-breathing detonation ramjet engine revealed last year.

At the core is a ramjet engine that drives test vehicles to hypersonic speeds. It appears deceptively simple—just a hollow tube with no moving parts—because it doesn’t use turbine blades to compress air. Instead, it harnesses the craft’s forward speed to do the job. The real challenge lies in regulating the air intake. A cone-shaped inner structure manages shock waves and decelerates the airflow to subsonic speeds—crucial to prevent the engine from overheating or disintegrating.

While the ramjet is effective, it has a major drawback—it can’t start working until it’s already moving at high speeds. To reach those speeds, it typically needs a booster rocket or must be deployed from a fast-moving aircraft, which complicates efforts to create a hypersonic vehicle capable of conventional takeoff.

How the Rotating Detonation Rocket Engine (RDRE) Works

That’s where the Rotating Detonation Rocket Engine (RDRE) comes in. First theorized in the 1980s, the RDRE operates using continuous, controlled detonations. It features a hollow cylinder with one open end, where a mix of fuel and oxidizer is injected. This mixture detonates, generating a supersonic shock wave that travels in a circular path, compressing and burning the remaining propellant.

The outcome is a powerful, high-pressure exhaust that delivers thrust with greater combustion efficiency and a superior thrust-to-weight ratio compared to standard rocket engines. By combining an RDRE with a ramjet, Venus Aerospace aims to create a hypersonic vehicle that can take off and land like a regular aircraft.

The May 14 test did not involve a full hypersonic vehicle; instead, the engine was launched nearly vertically like a rocket to simplify design and flight procedures. This approach aimed to prove the technology’s effectiveness under real-world conditions ahead of future tests—such as a drone featuring the VDR2 planned for later this year. The company’s long-term goal is to develop an advanced version of the engine to power the Stargazer M4, a reusable passenger aircraft capable of reaching Mach 4.

“After five years of effort, we’ve finally reached this breakthrough,” said Sassie Duggleby, CEO and Co-founder of Venus Aerospace. “We’ve demonstrated that our technology functions not only in simulations and labs but also in real flight. This achievement brings us closer to making high-speed travel more accessible, cost-effective, and sustainable.”

Read the original article on: New Atlas

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