In 2017, the European Space Agency (ESA) contracted the ArianeGroup to develop Prometheus, a liquid-fueled rocket engine prototype intended to pave the way for the creation of reusable rocket engines. The contract is worth about eighty-five million dollars. It was signed by Daniel Neuenschwander, the ESA Director of Space Transportation, and Alain Charmeau who is the CEO of ArianeGroup. At the time the project was launched, the ESA said that it would be testing the prototype engine late in 2020. This week, the ESA issued an update on the project.
Reusable rockets are very important to the future exploration and exploitation of space. They can be used multiple times before they have to be retired. They will significantly reduce the cost of each mission and make it possible to launch more missions at a faster rate. SpaceX has pioneered the reusable rocket industry making the possible real.
The Prometheus rocket engine will be fueled by liquid oxygen-methane propellants. The ESA says that these fuels are readily available and have high levels of standardization and efficiency. 3D printing will be used for some of the components of the rocket engine. This will allow complex parts to be made quickly, efficiently and inexpensively.
In addition to its lower cost and highly efficient fuels, the Prometheus engine will also be more flexible than current engines. The ESA says that it will be practical to use in a large variety of launch vehicles.
The ESA published and update on the Prometheus project on June 4 of this year affirming that it is moving ahead with this program. The ESA recently obtained full funding to evolve Prometheus to a technical maturity suitable for industry.
The agency believes that this new rocket engine will cost only a tenth of the Ariane 5 Vulcain 2 main stage engine. The Prometheus engine will be suitable for both the main stage and the upper stage of Ariane rockets, a demonstration of its flexibility.
Currently, the engine’s main subsystems are being manufactured. This process includes additive layer manufacturing (ALM) which is generally referred to as 3D printing. This process is faster than traditional manufacturing methods and it is able to produce complex parts that could not be manufactured by other processes.
For engine management and monitoring there is also an on-board rocket engine computer which is the component that the ESA says makes the engine “smart” and potentially useable. This computer enables real time adjustment and immediate diagnostics for potential reusability.
Some Prometheus parts are already finished and ready for testing. These include the pump inlet, turbine and gas generator valves. The initial combustion chamber model will be tested later this month assuming that everything goes according to plan. The full-scale prototype is called the M1. It will be assembled for ground testing next year. It is currently undergoing hardware validation tests by ArianeGroup at the DLR German Aerospace Centers Lampoldshausen testing facility in Germany. The ESA says that in the short term, the technology developed for the Prometheus engine may be applied to operation engines of older design.