LEAP 71 and metal additive manufacturing (AM) firm HBD have additively manufactured an aerospike rocket engine that can generate 20 tons (200 kN) of thrust.
At one-metre in height, the partners believe the engine to be the world's largest 3D printed aerospike.
The cryogenic methane/liquid oxygen engine, designated XRA-2E5, was engineered using Noyron, LEAP 71’s Large Computational Engineering Model and will be exhibited at TCT Asia in Shanghai next week. It 'shares its DNA' with two earlier Noyron-generated aerospike engines, which have both been hot-fired over the past 15 months, and has been designed for the upper stages of large reusable launch vehicles.
LEAP 71 is currently in the process of developing and testing larger and larger engines that are designed with Noyron and manufactured with AM technologies. Noyron uses first-principles physics, engineering logic, and manufacturing constraints to autonomously generate functional designs without human intervention, while the ten-laser HBD 800 machine (830 x 830 x 1250 mm) is said to have 3D printed the engine as a monolithic piece. Inconel 718, a high-temperature nickel superalloy commonly used in rocket propulsion systems, was the material of choice.
“Aerospikes are often considered the holy grail of space propulsion,” said Josefine Lissner, CEO of LEAP 71 and the principal architect of Noyron. “They promise major performance advantages over conventional engines, but their complex geometry has historically made them extremely difficult to design, manufacture and operate. We believe that by combining computational engineering with advanced additive manufacturing, we can finally make them fly.”
Aerospike engines use an 'inside-out' architecture with a toroidal combustion chamber and a central spike. For the XRA-2E5 engine, LEAP 71 has integrated a regenerative cooling strategy where the outer chamber is cooled by the cryogenic methane fuel, and the spike is cooled using liquid oxygen.
Unlike conventional engines with their bell-shaped nozzles, aerospikes maintain high efficiency from sea level to vacuum, making them particularly attractive for next-generation launch systems that re-use both stages of the rocket. In a fully reusable launch system, both the booster and the upper stage return to the launch site, requiring propulsion systems that operate efficiently inside and outside the Earth’s atmosphere and provide deep throttling capability.
“Just a year ago, producing an engine like this at this scale would have been impossible,” said Kevin Chen, Director of Marketing at HBD. “The physics-driven geometry of the aerospike, with shallow overhangs and intricate internal structures, pushes even advanced metal printing processes to their limits. Successfully producing the engine on the first build demonstrates the stability and precision of HBD’s large-format additive manufacturing platform and provides hardware ready to move toward hot-fire qualification.”
Per LEAP 71, the XRA-2E5 marks a 'major manufacturing validation milestone' for LEAP 71’s multi-year propulsion development effort with Aspire Space.
HBD will exhibit the aerospike at TCT Asia in Shanghai, Hall 7.1, Booth 7E35.
