System Aspects of European Reusable Staged-Combustion Rocket Engine SLME

Abstract

The full-flow staged combustion cycle rocket engine with a moderate 15 to 17 MPa range in nominal chamber pressure called SpaceLiner Main Engine (SLME) has been under investigation by numerical simulations since several years. Originally defined as the baseline propulsion system for the reusable rocket-based high-speed intercontinental passenger transport concept SpaceLiner, the SLME is now also used as a reference for closed cycle LOX-LH2-engines in several studies of future European RLV. A summary overview of the studied reusable cryogenic staged combustion cycle engines in Europe including related launcher applications is provided. Currently, the Swiss company SoftInway and DLR are jointly performing a de-risk study under contract to the European Space Agency (ESA) to preliminarily consolidate a staged combustion engine design. The launcher system high-level requirements on the main propulsion system as well as the engine system level requirements have been defined by DLR. The commercial AxSTREAM® software tool is implemented for the pre-design of the turbomachinery, preburners and main combustion chamber regenerative cooling. A preliminary engine control logic is established. Consolidated size, mass, and performance data are available by this analysis and are integrated in the engine model. Further, different engine architecture options like two side-mounted integrated power-heads or in-line oxygen pump and preburner are mechanically sized and results are evaluated in the paper.