Reusable Structures for CALLISTO

Abstract

In order to make access to space more affordable for both scientific and commercial activities the German Aerospace Center (DLR), the Japanese Aerospace Exploration Agency (JAXA), and the French National Centre for Space Studies (CNES) joined in a trilateral agreement to develop and demonstrate the technologies that will be needed for future reusable launch vehicles. In the joined project CALLISTO (Cooperative Action Leading to Launcher Innovation in Stage Toss back Operations) a demonstrator for a reusable vertical take-off, vertical landing rocket, acting as first stage, is developed and built. As long-term objective this project aims at paving the way to develop a rocket that can be fully reused, and the joint efforts of the three agencies will culminate in a demonstrator that will perform its first flights from the Kourou Space Center, in French Guyana. Having regard to the aspect of reusable structures, the development of design represents a special challenge since the components have to withstand a variety of complex manoeuvres for multiple times. Additionally, this technical complexity leads to limitations in size and mass which must be observed during the design process. The structures have to be studied very individually to meet all the requirements for reaching optimal performance during ascent, return and landing. This paper focuses on the design solutions for CALLISTO’s fairing, the aerodynamic surfaces and the approach & landing system with respect to their specific sizing load case during the mission. The challenging concept of deployable aerodynamic surfaces is especially highlighted as the deployment causes a significant transformation of the vehicles outer shape and consequently has direct impact on the trajectory. This also applies to the stowable landing gear that has been one main design challenge in the frame of CALLISTO.