Gizmodo Science Fair: A Rocket Engine That Turns Controlled Explosions Into Thrust

Venus Aerospace is a winner of the 2025 Gizmodo Science Fair for building and testing the world’s first high-thrust Rotating Detonation Rocket Engine (RDRE).

The question

Scientists have speculated about detonating rocket engines for decades—but how would one actually perform outside the lab? And could it represent a breakthrough in rocket propulsion and a new path toward more efficient spaceflight?

The results

Venus Aerospace, founded by a husband and wife team in 2020, pulled off the first test flight of its rocket engine earlier this year. The flight represented a major milestone for high-speed flight technology and brought the world one step closer to achieving commercial hypersonic flight.

On May 14, the Houston-based startup made history when its engine ignited and propelled a small rocket to an altitude of 4,400 feet (1,340 meters) above the New Mexico desert. 

“It’s one thing to have an engine on a test stand, it was roaring and doing all the things it needed to do, but it’s totally different when you go fly that engine,” Sassie Duggleby, co-founder and CEO of Venus Aerospace, told Gizmodo. “It was four years of dreaming…and it was perfect, the launch could not have gone better.”

The engine burned for seven seconds, producing 2,000 pounds of thrust (roughly 907 kilograms) and pushing the rocket to a speed of about 383 miles (616 kilometers) per hour—roughly half the speed of sound. The rocket flew for about 30 seconds before gliding its way down via parachute. 

RDRE produces thrust through a series of detonations, combining highly pressurized propellant with an oxidizer inside a combustion chamber. While traditional rocket engines ignite vehicles through exhaust, RDREs are propelled by shockwaves. “For every drop of propellant, we actually extract more energy, so it’s a more efficient combustion,” Duggleby explained.

The detonating engine has no moving parts; the combustion is produced by combining fuel and oxidizer, creating a supersonic wave that spins around its axis to generate pressure. Scientists first theorized about RDRE in the 1960s, performing experimental studies of rotating detonation waves. Today, new technologies such as 3D printing have taken RDREs from theory to reality.

Why they did it

Around seven years ago, Duggleby and her husband were living in Yokosuka, Japan. One Sunday afternoon, the couple was discussing whether to fly back to Southern California for Sassie’s grandmother’s birthday and whether or not to bring their daughters along on the 13-hour flight. 

What started off as a regular conversation on holiday logistics turned into the origin story of a groundbreaking startup when Andrew Duggleby brought up the idea of a rocket engine that could theoretically fly them home in an hour. “I literally laughed at him at that moment, but we flew that rocket engine three months ago,” Duggleby said.

A year later, the pair was working at Virgin Orbit when engineers tested RDRE at an academic level. In April 2020, a paper published in Combustion and Flame presented experimental evidence of continuous detonation in an RDRE, demonstrating its potential use for upper-stage rockets.

“We looked around at all the people, really smart, great people, we worked with, and were like, well, surely someone sees this engine and wants to go commercialize it,” Duggleby recalled. “Ultimately we realized it was us.”

The couple quit their jobs during the pandemic to chase their idea of building the detonating rocket. Venus Aerospace was founded in 2020 with the objective of engineering the world’s most efficient, reusable hypersonic engines. Since then, the company has raised more than $80 million in funding. 

Why they’re a winner

Over the past 10 years, the number of rocket companies has grown from just a handful of well-known players to hundreds of startups worldwide. Today, the business of rockets is booming, and access to orbit is at an all-time high with reusable vehicles and lower-cost missions. Rocket engine efficiency, however, has more or less stayed the same.

Venus Aerospace’s RDRE is designed to achieve 15% more efficiency than traditional rocket engines.

“To put that into perspective, the SpaceX engine that they use today is only around 2% more efficient than the [Saturn V engine] that we used more than 50 years ago [to launch the Apollo missions] ,” Duggleby said.

Achieving higher efficiency for rocket engines means less fuel consumption, greater power, increased payload capacity, and longer flight ranges, according to Venus Aerospace. The technology also has the potential to unlock high-speed travel for hypersonic aircraft.

“Hypersonic” refers to vehicles capable of traveling at Mach 5, the speed of sound, or faster. At those speeds, a plane could take off from Tokyo and land in Los Angeles in an hour. 

“The detonation engine, combined with what’s called a ramjet, is the holy grail of high-speed flight,” Duggleby said. “You could go from takeoff to Mach 4 or Mach 5 with one single engine, no moving parts. And that’s our ultimate dream.”

What’s next

Following the success of the first test flight, Venus Aerospace has received a lot of interest in its detonating engine for a wide range of applications from both commercial and defense clients. 

“We’re going to be continuing to push the technology to fulfill the interest we’re getting from a bunch of different groups that are very interested in integrating our engine into their systems,” Duggleby said. “We will continue to push the technology forward and actually get it deployed and out into the market.”

Duggleby jokes that the company has what they call a “rocket engine petting zoo,” once filled with failed prototypes before Venus’ engineers developed one that could actually fly. “You learn more by failure than you do by success,” she said. “We really encourage our team to fail quickly, learn from it, and then make the change.”

The team

This is a company-wide endeavor, but key contributors included Sassie Duggleby, co-founder and CEO; Andrew Duggleby, co-founder and CTO; Tom Barron, vice president of operations; Brian Heckler, vice president of finance; Nick Cardwell, vice president of products and advanced concepts; Dave Mahoney, senior director of flight operations; Aubrey Yates, senior director of manufacturing, integration, and logistics; Eric Wernimont, senior director of engineering; and Aubrey McCravey, director of testing.

Click here to see all of the winners of the 2025 Gizmodo Science Fair.