LEAP 71 and HBD Build World's Largest 3D Printed Aerospike Rocket Engine — 200kN Thrust

The Holy Grail of Space Propulsion Goes Metal

LEAP 71 and metal AM firm HBD have additively manufactured an aerospike rocket engine capable of generating 200 kN (20 tons) of thrust — and at one metre in height, they believe it to be the world's largest 3D printed aerospike.

The engine, designated XRA-2E5, was engineered using Noyron, LEAP 71's Large Computational Engineering Model, and printed on HBD's ten-laser 800 machine (830 x 830 x 1250 mm build volume) as a monolithic piece in Inconel 718.

Why Aerospikes Matter

"Aerospikes are often considered the holy grail of space propulsion," said Josefine Lissner, CEO of LEAP 71 and 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."

Unlike conventional bell-shaped nozzles, aerospikes maintain high efficiency from sea level to vacuum — making them ideal for fully reusable launch systems where both booster and upper stage return to the launch site.

From 20kN to 200kN in One Year

Just a year ago, LEAP 71 hot-fired two different 20 kN methalox engines. The XRA-2E5 represents a 10x scale-up and marks a major manufacturing validation milestone for the company's multi-year propulsion development effort with Aspire Space.

"Successfully producing the engine on the first build demonstrates the stability and precision of HBD's large-format additive manufacturing platform," said Kevin Chen, Director of Marketing at HBD. "It provides hardware ready to move toward hot-fire qualification."

The engine features regenerative cooling where the outer chamber is cooled by cryogenic methane fuel and the spike is cooled using liquid oxygen.

The XRA-2E5 will be exhibited at TCT Asia in Shanghai next week (Hall 7.1, Booth 7E35).