Experimental approach regarding the ignition of H2/O2 mixtures in vacuum environment

The paper, elaborated in the framework of the ESA activity "Green thruster for attitude control and orbital manoeuvres of small satellites (GREENTH)", focuses on the preliminary stages of an experimental program aiming to evaluate the feasibility and to increase the maturity level of a H2/O2 pulsed technology for small scale space propulsion applications. For demonstrating the capability of the H2/O2 mixture to be pulsed and ignited in a vacuum environment, the paper presents the main technical requirements, some addressing the thruster itself, related to system dimensioning, such as the nature of manoeuvres, the thrust level, the minimum impulse bit, the operating conditions, and some addressing the experimental campaign to be performed. The design of the experimental installation has taken into account the demands coming for the challenges and limitations raised by the small-scale satellites (telecommunications satellites or even CubeSats) applications, including vacuum system dimensioning, injection and ignition systems dimensioning and equipment and instrumentation specifications. The testing program covers the selected ranges of operational parameters and the operating sequences, for pulse mode and steady state tests, in order to determine the performance level and to evaluate the pulse repeatability, respectively to demonstrate the process stability.