He noted that, by comparison, metallic 3D-printing technologies produce structures at the rate of millimeters per minutes. It will use carbon composite materials, as it does with the Electron rocket, but using a new technology called automated tape laying that enables composite structure to be built at rates of meters per minute. Instead, Rocket Lab is focusing on the structure of the vehicle. “What we’re trying to do is build an engine that is hugely reliable and can fly again and again.” “That’s an area where we’re not innovating,” he said. While Archimedes is a new engine design, Beck said the company deliberately decided not to push the envelope in terms of its performance. It was also a factor in the use of methane fuel rather than kerosene, as the latter creates soot that takes time to clean from engines. That design requirement, he said, led to decisions such as having the rocket return to the launch site rather than land on a barge. “Not because I intend to relaunch the vehicle every 24 hours, but it drives all of the design decisions,” he said. That includes, he said, a design decision early on to be able to turn around that first stage for another launch within 24 hours of landing. Every decision is based around that,” Peter Beck, chief executive of Rocket Lab, said in an interview. “We’ve really optimized the vehicle from day one to be reusable. The first stage will have seven Archimedes engines while the upper stage will have a single vaccum-optimized version of the engine. Neutron will be powered by a new engine called Archimedes, using methane and liquid oxygen propellants and generating about 225,000 pounds-force of thrust. The vehicle will be able to place 8,000 kilograms into low Earth orbit while recovering the first stage, or up to 15,000 kilograms if the first stage is expended.
Neutron then releases a lightweight, expendable upper stage with the payload before the fairing closes and the stage reenters. Rather than jettison the rocket’s payload fairing during launch, the “Hungry Hippo” fairing opens in four parts.