Evaluation of Future Ariane Reusable VTOL Booster Stages

Paper number

IAC-17,D2,4,3,x37322

Author

Mr. Etienne Dumont, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Germany

Coauthor

Mr. Sven Stappert, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Germany

Coauthor

Dr. Tobias Ecker, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Germany

Coauthor

Mr. Jascha Wilken, DLR German Aerospace Center - Institute of Space Systems, Germany

Coauthor

Dr. Sebastian Karl, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Germany

Coauthor

Mr. Sven Krummen, DLR German Aerospace Center - Institute of Space Systems, Germany

Coauthor

Dr. Martin Sippel, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Germany

Year

2017

Abstract

Reusability is anticipated to strongly impact the launch service market if reliability and low refurbishment costs can be achieved. The European space industry is closely monitoring the advances in reusability as it offers the potential to further enhance market competitiveness.  DLR has been performing an extensive study on return methods for a reusable booster stage for a future launch vehicle in the class of Ariane 6. Within the research effort both un-winged and winged first stages are considered, the current study concentrates on the vertical take-off and vertical landing (VTOL) method, similar to the one already implemented by Blue Origin and SpaceX. 
First a restitution of some flights of Falcon 9 is presented in order to assess the accuracy of the tools used. Then the preliminary design of different variants of a future Ariane launch vehicle with a reusable VTOL booster stage is described. This launch vehicle is capable to launch a seven ton satellite into GTO from the European Spaceport in Kourou. Among others, different staging and propellants (LOx/LH2 and LOx/hydrocarbon) are considered and evaluated with regards to their advantages and drawbacks. An important aspect for the preliminary design is the structural sizing, including the load cases characterising the ascent and the toss-back flight of the first stage. The ascent trajectory is optimized, taking into account its influence on the first stage descent propellant requirement and consequently on the payload performance. The most efficient trajectory is selected. As for the descent of the first stage, it is optimized to minimize the propellant consumption. Another important aspect is the aerothermal environment stressing the structure. During the re-entry boost, the first stage is immersed in the engine exhaust plume. RANS calculations have been performed to characterise the flow field around the first stage. These results are then coupled with a simple structural model to study the time dependent heating of the hull structure. Knowledge of the thermal loads allows choosing trajectories for which none/minimal thermal protection is required. Finally a comparison of the different concepts and an evaluation of the suitability of reusable VTOL booster stages for the requirements of the European space industry are given. 

Note: This paper is connected to another DLR’s paper on the comparison between winged and un-winged reusable booster stages.

Abstract document

IAC-17,D2,4,3,x37322.brief.pdf

Manuscript document

IAC-17,D2,4,3,x37322.pdf (🔒 authorized access only).

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