Thrust-chamber pressure is one of the most important performance parameters of all modern rocket engines. The higher the pressure, the greater the efficiency with which the engine converts the chemical energy of the fuel into thrust. To attain high operating pressures, high-performance engines need additional gas-generator combustion chambers to power the fuel pumps. These gas generators play a crucial role in the development of an engine for the next generation of the European Ariane launcher family. At the DLR site in Lampoldshausen, the Institute of Space Propulsion operates an experimental combustion chamber equipped with a porous injector (API, Advanced Porous Injector) to investigate the injection and atomization conditions typical for gas generators. In one test run, the combustion chamber reached a pressure of 330 bar at the European research and technology test bench P8, a European record for gas-generator combustion chambers.