ProjectX is the collaboration between Ph.D students at the Laboratory for Turbulence Research in Aerospace and Combustion (LTRAC) and Amaero additive manufacturing. Engineers at Amaero approached the students, asking them to build a cutting edge rocket design that could fully utilise the limitless geometric complexity of the additive manufacturing process in just 4 months. The aerospace graduates discussed, before suggesting to design, build, and test one of the most complicated rocket engines of all: the aerospike nozzle. ProjectX is in someways both the most complex and simplest rocket engine. Although the engine is extremely geometrically complex, the gaseous propellant system using compressed natural gas (CNG) and gaseous oxygen has allowed the graduates to focus exclusively on the design. The challenges of making the aerospike engine operate efficiently and not melt in the process was their primary focus. The engine has a design thrust of 4kN.
The aerospike engine is additively manufactured in a two piece construction. The rocket body is printed in one continuous piece, which eliminates the requirement for high temperature metal-to-metal gas seals. The aerospike is printed next to the body and the exterior surface is precision machined on a CNC lathe. The spike is inserted and held in place by the internal chamber fins and an intricate locknut arrangement. Due to high combustion temperatures inside the engine, active liquid cooling is necessary. Both the engine body and spike have a complex subsurface of millimeter deep liquid cooling channels. The cooling channels pass cooling fluid through the engine before returning it to the reservoir. The ProjectX aerospike engine cannot be made by traditional manufacturing processes.