When Moon Express mounts what it hopes to be the first private expedition to the moon later in 2017 in its quest for the Google Lunar X Prize, it will be doing so using an unproven rocket, the Electron, built by a company called Rocket Lab. The Electron, according to 3D Printing Industry, is powered by the Rutherford engine, the first to be constructed with primarily 3D printed parts. If the rocket succeeds, it will represent a leap and a first in engine technology.
Every primary part of the Rutherford, including the engine chamber, injector, pumps, and propellant valves, have been 3D printed using a method called electron beam melting (EBM).
EBM, developed by a Swedish company called Arcam AB, uses an electron beam to melt metal powder or wire and apply it layer by layer to create a part or item while in a vacuum. The process allows the fabrication of lighter weight components than is possible using conventional methods. Lower weight with the same or greater strength and performance is an important consideration for aerospace manufacturing.
Rocket Lab is not the only entity to use 3D printing to build rocket engines. Companies such as SpaceX is using 3D printed parts for its Falcon 9 launch vehicle. The company plans to use a 3D printed rocket engine, the Raptor, to take people and cargo to Mars. NASA is using the same manufacturing method to build the heavy-lift Space Launch System (SLS) that it expects to be the rocket that will take people to the moon, Mars, and beyond.
One great advantage of 3D printing is that it allows for rapid prototyping. Components for a 3D printed rocket use a computer aided design (CAD) system to create the parts. Engines can alter the design on a computer, print the redesigned part, and test it in far less time than it takes using conventional methods. This ability will allow for continuous improvement of rocket engine technology at a far more rapid pace than has hitherto been the case.
Rocket Lab intends to start test flights of the Electron in March. Provided that the rocket works as expected, Moon Express should be able to mount its first mission to the moon later in 2017.
