Rutherford (rocket engine)

Description

The Rutherford engine takes its name from New Zealand scientist Ernest Rutherford. It is a compact liquid-propellant rocket engine built to be straightforward and inexpensive. It functions in both first and second stages, which streamlines supply chains and boosts cost efficiency. To keep costs down, it employs an electric-pump feed cycle, making it the first engine of this kind to reach flight readiness. Most of its parts are made through 3D printing, specifically laser powder bed fusion known as Direct Metal Laser Solidification (DMLS®); the combustion chamber, injectors, pumps, and main propellant valves are all printed this way. Like any pump-fed engine, it uses a rotodynamic pump to boost propellant pressure from the tanks to the combustion chamber, eliminating the need for heavy high-pressure tanks and large volumes of inert pressurization gas. The fuel and oxidizer pumps are each driven by dual brushless DC electric motors, powered by a lithium polymer battery. This setup is said to raise efficiency from about 50% in a typical gas-generator cycle to 95%, though the battery adds weight and introduces an energy conversion challenge. Each engine has two small motors producing 50 horsepower at 40,000 rpm. The first-stage battery, which must run nine engines at once, can deliver over 1 megawatt of power. The engine uses regenerative cooling: cold RP-1 flows through channels in the combustion chamber and nozzle before being injected, carrying heat away.