LEAP Space 3D-Printed a Rocket Engine in One Piece for Bighorn

A Single Part, No Assembly

LEAP Space has unveiled the Serrano engine, the first major piece of hardware for its Bighorn launch vehicle. The company printed the thrust chamber as a single part using large-scale direct metal laser sintering. No welding, no bolting, no assembly. The chamber comes off the build plate ready for integration.

The approach mirrors the one LEAP used for its smaller Anaheim engine, which has already flown. Serrano scales that same design philosophy up to a larger size. The result is a propulsion system that can be produced and iterated faster than a conventionally machined engine.

Why 3D Printing Matters Here

Rocket engine combustion chambers are notoriously difficult to manufacture. Traditional methods require casting, forging, and extensive machining, followed by welds that must be inspected and tested. Each weld is a potential failure point. Each machining step adds time and cost.

By printing the chamber in one piece, LEAP eliminates many of those steps. The company says this lets it test design changes quickly, printing a new iteration in days rather than waiting weeks or months for tooling. That speed matters when the goal is to reach a production rate of more than 30 vehicles per year per manufacturing line.

The Bighorn Design Philosophy

Bighorn is designed with 90% fewer parts than conventional launch vehicles. That number sounds extreme, but it reflects a deliberate choice to remove complexity wherever possible. Fewer parts mean fewer suppliers, fewer assembly steps, and fewer things that can go wrong during integration.

The Serrano engine fits into that philosophy. A printed thrust chamber is both a component and a statement: if you can print the hardest part of the rocket, you can print most of the rest.

What Comes Next

LEAP plans to integrate the Serrano engine into Bighorn and continue testing on the path to flight. The company currently operates two vehicles: Bullfrog, a reusable point-to-point logistics craft that completed its first flight in May 2026, and Bighorn, which targets orbital missions, defense contracts, and point-to-point transport.

The printed engine is not just a technical achievement. It is a production strategy. If LEAP can build engines this quickly and this cheaply, it changes the economics of small-lift launch. Competitors still relying on cast-and-machine methods will have to match that cadence or find a different race to run.