VENUS - CONCEPTUAL DESIGN FOR VEGA NEW UPPER STAGE

Abstract

With the first launch of VEGA approaching, the European launch vehicle family will soon be completed. VEGA aims at transporting small research- and earth observation satellites to Low Earth Orbit (LEO). Ongoing investigations show the opportunity for a performance improvement of the launcher to cope with the market demand for evolution in P/L mass. Therefore, studies to enhance the capabilities of the launch vehicle were started. The German Space Administration (DLR) has funded the VENUS (VEGA New Upper Stage) studies on behalf of the German Federal Ministry of Economics and Technology with Astrium Space Transportation as Prime Contractor and the DLR institute for Space Launcher Systems Analysis (SART) as subcontractor, in order to identify and assess the potential of increasing the upper stage performance. The second slice of the study, the so-called VENUS-2 study (support code FKZ50RL0910), was started in July 2009 and has been finalized mid 2011. VENUS-2 aims at investigating possible evolutions of the VEGA-launcher upper stage. In particular, conceptual lay-outs for new storable propellant upper stages have been investigated including engines. The VENUS-2 study is divided into three study phases. Phase 1 work was focused on conceiving and analysing different new upper stage architectural concept candidates and selecting reference concepts on the basis of trade-offs and by optimization of overall launcher P/L performance. After this phase the main parameters were frozen. Phase 2 focuses on the Conceptual Design during which dedicated stage mechanical designs and trade offs were conducted, as well as thermal studies on the thermal behaviour of the stages, lay-outs of the functional propulsion systems, propellant and helium budgets on the basis of more detailed analyses, needed electrical interfaces between upper stage and avionics equipment, trade-offs for the separation systems, dedicated designs for the engines AESTUS-2 and BERTA, resulting mass budgets, and adapted launcher performance characteristics in order to update the maximum payload mass. Further, in Phase 3 development logics and plans were established. In parallel to the study work experimental demonstration on new injector concepts addressing the BERTA engine have been conducted.