A Minimum R&T Program on Air-Breathing Propulsion For Europe

Since the 80's, a lot of Research and Technology efforts are led worldwide on high-speed airbreathing propulsion and its combination with rocket propulsion for space launcher application. Europe contributed to this effort mainly through several national programs. But, due to the lack of a real involvement of ESA in that specific field, such national programs ended without clear conclusion on interest and feasibility of highspeed airbreathing propulsion for future European space launching systems. Today, in Europe, know-how and available means are still maintained or developed through individual national initiatives while the effort is continuously pursued at a high level in the other leading Nations (USA and Japan particularly) but also in China, India and Russia. The paper briefly reviews the past experience and presents activities in Europe in this field, and try to give a view on the most promising propulsion concepts using a high-speed airbreathing mode for future European space launching systems. For these promising concepts, the critical technologies are identified. For each of them, a minimum technology development and demonstration program, compatible with possible European budgetary effort, is proposed in order to allow Europe to stay "in the race" in case airbreathing propulsion would become a key technology for the development of new generations of space launchers in the next decades.