Aerospike engines, known for their unique design and efficiency, address a key challenge faced by traditional bell-shaped rocket nozzles.

According to New Atlas magazine a rocket that works very well on liftoff will work less well as it rises in the atmosphere and the air pressure decreases. This is why second- and third-stage rocket engines are different from those of the first stage.

Aerospike technology uses a spike-shaped or plug-shaped engine with a curved design, enabling it to adapt to changing atmospheric pressures.

Unlike traditional nozzles, the aerospike forms a "virtual bell" using the combustion gases flowing over the spike and the surrounding air pressure. As air pressure changes, so does the shape of this virtual bell, making the aerospike significantly more efficient across various atmospheric conditions.

Despite its promise, the aerospike has yet to see widespread adoption in spaceflight. LEAP71 aims to change that with its proprietary Noyron Large Computational Engineering Model, an advanced AI system designed to rapidly optimise rocket engine designs.

"Noyron allows us to radically cut the time we need to re-engineer and iterate after a test and enables us to converge rapidly on an optimal design," said the company.

By simulating physical interactions, including thermal behaviors and performance metrics, Noyron generates refined designs based on input parameters. These designs are fed back into the system to further improve future iterations.

LEAP71’s aerospike engine was manufactured as a monolithic piece of copper using industrial 3D printing, and the entire process—from design to testing—was completed in just a few weeks. The engine performed flawlessly during its first hot fire test, part of an ambitious four-engines-in-four-days campaign conducted at Airborne Engineering in Westcott, UK.

“Aerospikes are more compact and significantly more efficient across various atmospheric pressures, including the vacuum of space,” the company said, describing their prototype as "one of the most advanced and elusive rocket engines ever created," the company said

The data collected from the test will be analyzed to refine the Noyron AI system further. LEAP71 plans to continue testing throughout 2025, aiming to make aerospike engines a practical choice for modern spacecraft.