Investigations and Considerations about Reusable LOX-HC Engines as Key Technology for Future Launch Vehicles

Abstract

The aim of this paper is to investigate LOx/HC engines (focusing in particular on methane and kerosene as propellant), in order to evaluate their capability to support space activities in the frame of RLV scenario. Analysis at system and technological levels are made referring to engines of 200 -300 tons of thrust to be used in cluster configuration on future RLV. The considered architectures are cluster of 2 engines for booster configurations, and cluster of 3 engines for first reusable stages of future TSTO with cryogenic second stage. A trade off analysis of different LOx/HC propellant pairs is performed, whose main result is that LOx/CH 4 is one of the best possible choice for RLVs first stages, due to high methane cooling capability and performance. A comparison between kerosene and methane fundamental physical-chemical and termodynamical properties is reported too. The paper is divided in 3 sections: system analysis, propulsion technologies, thrust chamber. The first section is devoted to system level analysis about launch vehicles coupled with reusable engines, in order to define capability and operational flexibility. The second section is dedicated to key technologies for new reusable 200 -300 tons class engines, particularly focusing on materials, cooling and injector plate issues.In the third section injection of liquid oxygen and gaseous methane in supercritical conditions is analysed.Finally a roadmap on the development of a reusable engine related technologies is proposed.

Conceptual study of a dual-rocket-based-combined-cycle powered two-stage-to-orbit launch vehicle

“…A trade-off hydrocarbon fuel, methane, which provides a balance to obtain some of the benefits of hydrogen and kerosene in one single fuel, has become the research hotpot. 21 Some basic thermodynamic properties of these fuels are given in Table 1. 22 Institutions in the USA, Russia, China, and Europe have already done some work on the research of LOX/methane LRE, including its thermodynamic cycle, flame stabilization, comparison of kerosene and methane as rocket fuels, and so on.…”