Nature-inspired rocket-nozzle redesign stands by for liftoff

When it comes to rockets, bell-shaped engines are the norm. But they’re not the most efficient shape. Engineers have relied on this design only because it avoids a known overheating risk faced by a more efficient engine. Now, though, three 17-year-olds have redesigned the nozzle of the more efficient aerospike engine to better manage heat.

They’re hoping that one day their new tech might literally shoot for the stars.

Devin Wanchoo, Michael Obeng and Mazon Ben Chouikha attend Governor’s School at Innovation Park in Manassas, Va. Their new work began as a way to satisfy a class assignment. “We wanted to do something in aerospace. We wanted to do something involving biomimicry. And then we wanted to do something that no one has done before,” says Michael.

Those motivations led them to refine a better rocket system.

During their research, the young engineers learned that bell-shaped rocket engines become less powerful the higher they ascend. For decades, engineers have experimented with an alternative that would avoid this limitation: the aerospike engine.

Unfortunately, this design has its own big limitation: It shoots super-hot exhaust gases from the engine right up against its spike structure. Eventually, that heat can “cause the spike body to melt and crack under thermal stress,” Devin says.

Their work won these teens a spot here at the 2026 Regeneron Science and Engineering Fair, or ISEF. The event is a program of the Society for Science (which also publishes this magazine). The young aerospike researchers were among 1,725 students — from 65 nations or territories — who competed at the 76th annual ISEF. These participants shared nearly $7 million in prizes.

A guiding spike

Imagine a rocket launch. Flames burst downward from the engines and propel the rocket upward. Initially, the flames form a column.

If you were to fly alongside the rocket as it ascends, you’d eventually see the shape of that exhaust change. The column of gases would start to balloon outward.

During liftoff, high atmospheric pressure initially forces the gases into that column shape. But as the rocket climbs, the air pressure weakens — and so does control of the exhaust gases. Now they spread out, reducing lift.

The thrust must go down for the rocket to go up. But higher up, as the gases balloon out, bell-shaped engines “can lose up to 30 percent of their efficiency,” says Devin.

Engineers have been looking to overcome that. And the aerospike engine is one possible solution.

“Unlike a bell nozzle — which needs that giant encasing structure — the aerospike just has its central spike,” Devin explains. It will deliver a strong, reliable upward thrust as long as you have some way “to force gases [down] along the spike wall.”

Those gases flow along the spike’s surface. The spike acts as a guide to direct the gases down so they can’t spread out. But that guiding spike introduces its own problem.

Coming from the engine, exhaust gases “are extremely hot,” notes Michael. The spike’s tip takes a pummeling from those gases. Their heat is “essentially attacking it, attacking it, attacking it,” he says.

What’s more, those gases tend to recirculate along the spike. This helps counter the air pressure’s attempt to weaken the downward flow of the gases, Michael says. Unfortunately, he adds, it also increases the heat.

So what makes this engine so good at maintaining a strong downward flow of exhaust gases, Devin points out, “is the same thing that causes that very aggressive heating of the spike body.”

Typical cooling methods just haven’t been good enough to spare the spike.

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Nature-inspired

To counter that, the trio looked for inspiration in nature. Living things have evolved different ways to cool themselves. The team considered plant veins, insect exoskeletons, shark tissues and more. Then the trio created ICARUS, a machine-learning algorithm, and used it to test bio-based cooling strategies.

ICARUS, says Devin, is “probably the most novel part” of their project. It’s a simpler, heat-driven version of tools used by the aerospace industry. And it does more than just test ideas. “We built it on a machine-learning layer that was able to suggest [spike shapes] to try,” Devin says.

The young engineers started with shapes suggested by nature. Then they used ICARUS to optimize those designs. For instance, says Mazon, his team might suggest a certain surface pattern or feature. Then ICARUS “might change the width of it [or] the depth of it” to optimize the spike’s heat resistance.

The approach worked. Heat flux refers to how fast heat moves through a material. “We were able to reduce temperatures and heat flux by up to 40 percent,” Devin says.

Human skin inspired their most successful design, Devin says. Pores in our skin release sweat. As it evaporates, it wicks away heat. Mimicking this trick helped “bleed propellant to fight back against that heat creep,” says Devin.

Validating ICARUS

Using what they learned from ICARUS, the team members 3-D printed models of the six most promising designs. Then they put the models under a heat gun and measured how long each took to reach 90° and 110° Celsius (194° and 230° Fahrenheit), says Devin. They also tracked at what temps the models began to warp.

Then they built a copper prototype of their best-performing model. In the final stage of testing, Michael says, they became the first high school students to ever do a cold-flow test on such an engine. A cold-flow test, explains Devin, is “just testing that your engine can pressurize properly and that propellants are flowing.”

This test was “pretty cool,” he says. “We got to verify our ICARUS predictions.”

ICARUS can also offer design tips beyond rocketry, Mazon says. For instance, the surface patterns designed to manage heat could even be applied to homes. “If you were to put [these patterns] on wood and you built the house, then it’s very likely to be safer” in terms of withstanding wildfires, he says.

For their work, Devin, Michael and Mazon took home fourth place — and $600 — in ISEF’s Engineering Technology: Statics and Dynamics division.