Constructed using 3D printing technology, the Prometheus is a liquid-fueled rocket engine demonstrator that is intended as the model for the next generation of potentially reusable propulsion systems suitable for a wide variety of launch vehicles. Being developed for ESA by ArianeGroup, it promises to be the precursor to rocket engines that are cheaper and more flexible than current designs.
With commercial launch companies coming of age, state-run space agencies are coming under increasing pressure to cut costs to remain competitive. One way to do this is to create new engines that are less expensive to develop and build, can be installed in different rockets in different configurations for different missions, and can be reused.
ESA is betting that Prometheus will lead to new engines that are 10 times cheaper to manufacture than the current main stage Ariane 5 Vulcain 2 engine thanks to a design-to-cost approach to development.
According to the space agency, the Prometheus can be used for both the main and upper stages of launch vehicles, it has variable thrust, can carry out multiple ignitions and needs only minimal ground operations before and after flight. In addition, it runs on a liquid oxygen–methane propellant, which is simpler to handle than some other fuels, and is easier to source.