Assess the potential system simplifications and cost reductions related to optical fibre-based ignition system for cryogenic RCS bydesigning and manufacturing an optical fibre-based ignition system using a pre-existing laser ignition system

 

Current launcher RCS thrusters operate with storable, hypergolic propellants. They do not need an ignition system, but these propellants have a negative environmental impact and, due to the high and therefore expensive effort for safe handling and fuelling of the tanks, alternatives have to be found to replace them. One alternative is the use of cryogenic propellants available in the launcher for the RCS thrusters, or storable green propellants for thrusters on long-duration missions, combined with a laser ignition system. As multiple thrusters are needed on a single spacecraft, multiplexing of one core laser system with optical fibres could minimize the additional weight of the ignition system.

 

Another challenge for cryogenic liquid rocket engines is reliable re-ignition. Recent research and development activities have proven the feasibility and robustness of laser-based ignition systems. So far, the laser has to be attached to the main combustion chamber to be ignited. For fibre-based systems, the free positioning of the core laser system would increase the flexibility of integration with the launcher architecture. Multiplexing of the laser-based ignition source would also allow for redundant and distributed ignition systems for multiple engines on the same launcher, for example in the platform architecture currently proposed for the Prometheus engine.

 

The aim of this project is to design, build and test such a prototype fibre-based ignition system for both application scenarios. A work package of this activity shall be dedicated to the assessment of economic benefits of such an ignition system for the intended applications.