SoftInWay and DLR SART to Design New Generation of Staged Combustion Rocket Engines for ESA

Zug, Switzerland, February 20, 2024 – SoftInWay Switzerland, a part of SoftInWay Group, has embarked on a new project on staged combustion for the European Space Agency (ESA), as the agency considers a new generation of engine propulsion systems for reusable rockets. The project will be done in collaboration with the Space Launcher Systems Analysis (SART) department of the German Aerospace Center (DLR) and is funded by the General Support Technology Programme (GSTP).

Beyond its promising fuel efficiency and low carbon footprint, staged combustion technology, in particular full flow cycles, is especially fitting for reusability given its notable capacity to keep components cooler and thus significantly extend their service life. While staged combustion engines are in use by US companies such as Blue Origin and SpaceX, ESA is looking to expand the technology’s prevalence in Europe.

The project will primarily involve analysis of state-of-the-art staged combustion cycle variants, with the target of finding viable ones to satisfy desirable engine performance characteristics. The results are expected to not only uncover a range of requirements for major components and subsystems, but also identify key areas of potential risk and related safety considerations.

When asked about the project, Dr. Vasileios Pastrikakis of SoftInWay, who is leading the project, stated: “Technology is in a constant state of evolution, and rocket engines are no exception. While studies on staged combustion have been conducted in the past as part of ESA-funded activities, some of these studies were carried out over two decades ago and were tailored to substantially different goals and operational requirements. A bit more technically, the main objective of this activity is to achieve a feasibility assessment of a European LOX-LH2 staged combustion cycle rocket engine. Good understanding of the technical implications on performance, mass, and cost of such rocket designs is an important goal of the project. With software tools such as AxSTREAM.SPACE, along with the brilliant minds at DLR and ESA, we can help push the boundaries of the European Space Industry and usher in a new era of propulsion technology.”

Dr. Martin Sippel of DLR stated that he is happy to see the envisioned engine of the SpaceLiner concept selected as the reference case, guiding the study’s high-level requirements. This advanced, fully reusable multiple mission space transportation concept is ideally suited as its mission should one day include also commercial passenger point-to-point transport. The engine itself is already useful for Europe’s next generation of high-performance launchers in the next decade, reaching from medium size up to the class of super heavy vehicles.

The SpaceLiner is an advanced concept for a suborbital, hypersonic, winged passenger transport, which is currently under investigation at DLR-SART. AxSTREAM.SPACE is SoftInWay’s flagship software bundle for the design of liquid rocket engines. Its propulsion system modeling capabilities have proven to be especially useful in this project, specifically for modeling thermodynamic cycles and thermal-fluid networks (both steady and transient). This tool, which has been utilized in various feasibility studies, is currently in use by SoftInWay clients in space propulsion and will be shared with DLR teams. Additionally, AxSTREAM.SPACE, will be used to model the turbomachinery components of the rocket engine.


About SoftInWay Switzerland

SoftInWay Switzerland, a part of SoftInWay Group, is an R&D engineering company specializing in the development of efficient propulsion and energy conversion systems. Its integrated and automated software platform, AxSTREAM®, covers all stages of design, redesign, analysis, and optimization of the turbomachinery used in energy and propulsion technology. AxSTREAM encompasses comprehensive 3D design, thermodynamic cycle analysis, rotor dynamics simulation, and secondary flow and cooling system optimization. SoftInWay also offers engineering consulting services and educational courses, available both in-person and online.

SoftInWay supports 500+ companies worldwide and works closely with OEMs, service providers, utility companies, universities, research laboratories, and government organizations. You can find more information at

About DLR (Deutsches Zentrum für Luft- und Raumfahrt)

DLR is the German national research center for aerospace research and also has the role of Germany’s space agency. DLR’s Space Launcher Systems Analysis division (SART) is responsible for the simulation and pre-definition of all kinds of future space transportation systems and related propulsion systems. See