At the Up.Summit 2024 organized by UP.Partners last week in Bentonville, AK, Venus Aerospace unveiled its Venus Detonation Ramjet 2000 lb Thrust Engine, also known as VDR2, marking a major breakthrough in the Houston, TX-based startup’s pursuit of high-speed flight. The company’s advanced propulsion system is engineered to power vehicles, including drones and aircraft, for traveling vast distances at high altitudes and achieving high-Mach speeds with unmatched efficiency.

The VDR2 combines the high thrust and efficiency of a rotating detonation rocket engine (RDRE) with the high-efficiency cruise of a ramjet. This offers a single engine from take-off to as fast as Mach 6, with a streamlined airflow design for low drag that is said to eliminate the need for complex mechanical components. The innovation would go beyond supersonic, meaning faster than the speed of sound, to the hypersonic realm, meaning at least five times faster than the speed of sound—or Mach 5.

“This engine makes the hypersonic economy a reality,” said Dr. Andrew Duggleby, Co-founder and CTO at Venus Aerospace, who unveiled the engine at the event. “We are excited to partner with Velontra to achieve this revolution in high-speed flight, given their expertise in high-speed air combustion.”

Velontra is building the engine’s host hypersonic space plane. Combining technologies allows both Venus Aerospace and Velontra to take tangible steps toward their shared vision of unlocking the high-speed flight economy in the commercial and defense sectors.

“We can’t wait to dig in, make the first one fly, and ultimately perfect an engine concept that has lived mostly in textbooks but never as a production unit in the air,” said Eric Briggs, Chief Operating Officer at Cincinnati, OH-based Velontra. “We couldn’t think of a better partner than Venus. Rocketry pioneers in their own right, and ready to tackle the hard problems, we are eager to fly the same path with them.”

The VDR2 will take flight in Venus’ hypersonic flight test drone in 2025.

One possible application is the Venus Stargazer M4, what the company calls the first hypersonic, reusable aircraft that it says could make two-hour global transport cost-effective. Its flagship product Stargazer, planned to arrive in the 2030s, will ascend from a central airport leveraging the RDRE Ramjet to accelerate from taxi to cruise speeds of Mach 4 at 110,000 ft (33,500 m) with a top speed capable of Mach 9.

Co-founded in 2020 by Andrew and CEO Sarah “Sassie” Duggleby, venture-backed Venus Aerospace has raised $70 million so far, from key investors like Airbus Ventures and Prime Movers Lab, to develop reusable high-speed technology for “revolutionizing and redefining the boundaries of aviation, defense, and beyond.” The company’s focus is on engineering the future of dual-use hypersonic technology. Its expert team of PhDs, rocket scientists, and engineers are taking on the biggest challenges in aerospace for Mach 9 speed to make “one-hour global transport possible to connect the world and make it safer.”

In March, Venus announced it had achieved all engine milestones and successfully flew its inaugural supersonic drone in February. The 8-ft (2.4-m), 300-lb (136-kg) test drone was dropped at an altitude of 12,000 ft (3650 m) and accelerated to a top speed of Mach 0.9, flying for 10 mi (16 km). It was powered by a hydrogen peroxide monopropellant engine at 80% thrust to not exceed Mach 1. The test successfully demonstrated flight controls, stability, one leg of the ultimate RDRE propulsion system, telemetry, ground operations, and air launch.

“Using an air-launched platform and a rocket-with-wing configuration allows us to cheaply and quickly get to the minimum viable test of our RDRE as a hypersonic engine,” said Andrew Duggleby. “The team executed with professionalism and has a wealth of data to anchor and tweak for the next flight.”

“This is how you do hard things: one bite at a time,” added Sarah “Sassie” Duggleby. “Up next is RDRE flight, and ultimately hypersonic flight, proving that the RDRE is the engine that unlocks the hypersonic economy.”

Just before the drone test, the company announced it had achieved the first long-duration engine test of the RDRE in partnership with U.S. Department of Defense‘s DARPA (Defense Advanced Research Projects Agency). Achieving the first hot-fire, long-duration engine test of Venus’ RDRE is a significant feat, as it previously had only undergone short-duration tests, which run uncooled hardware for quick and inexpensive test iterations.

Venus has been awarded contracts by several U.S. government agencies to accelerate the development and potential transition of its RDRE technology for hypersonic and space missions. RDREs are much smaller and more efficient than traditional rocket engines and can be easily configured for hypersonic vehicles. RDREs theoretically can achieve an additional 15% efficiency over traditional rocket engines, which directly leads to reduced propellant consumption, allowing them to fly farther on less fuel.

The company’s RDRE is unique in its use of storable and stable liquid propellants which makes for safer operations, faster load times, and avoids boil-off of the propellant. In January, it announced that it had partnered with NASA‘s Marshall Space Flight Center to achieve one of the longest sustained tests of an RDRE. Its engine injector was the highest-performing and sustained the longest detonation run of the entire campaign.

Using a regeneratively cooled RDRE architecture, the engine successfully operated for 4 min of hot-fire testing. This is a significant milestone given most engine tests of this type last for only 1-2 s. This long-duration hot fire meant that RDREs had “retired a major risk area” and could move into the few remaining steps before a flight demonstration.

The partnership with NASA is accelerating Venus’s research and development, allowing for the proven scalability of its technology and advancing the team’s mission to unlock the hypersonic economy. NASA is considering using RDREs for in-space applications such as lunar and Martian landers, in-space operations and logistics, and other deep-space missions.

Venus is in its second year of the contract to provide engine parts for the research and development of NASA’s RDRE. The two will test different propellant combinations on hardware, to operate at even higher thrust levels, and to demonstrate efficiency gains promised by the detonation engine. This will help Venus expand its knowledge base and move technology onto flight vehicles.