Further Progress in Aerodynamic Studies for CALLISTO - Reusable VTVL Launcher First Stage Demonstrator

DLR, CNES and JAXA jointly continue the developing of a vertical take-off and landing (VTVL) reusable subscaled first stage demonstrator CALLISTO, which has to show the capability to launch, land and relaunch a vehicle under conditions representative for the first stage of an operational launch vehicle in the several demo-flights. Furthermore, during CALLISTO demonstration flights, data will be gathered to improve knowledge on the operation of a reusable vehicle which will help to optimize the reusability capabilities of future launch systems [1-2]. The key challenge is to create an extensive aerodynamic data base covering all the flight configurations and conditions. Indeed, the aerodynamic performance plays a central role in the global performance of CALLISTO. In the period of 2020-2022 the extensive aerodynamic database (AEDB) with uncertainties and aerothermodynamic database (ATDB) based on the numerous CFD-simulations and wind tunnel measurement campaigns were created. The actual AEDB and ATDB relate to the detailed layout of CALLISTO corresponding to the state of 2019-2020 called aeroshape CAL1C. At the same time, in the process of design development, significant changes and details were made to the layout of the demonstrator, resulting in a new aerodynamic shape called CAL1D (state 2022). The limited computing resources and time plan do not allow repeating all CFD-simulations and wind tunnel test campaigns performed for CAL1C. The paper will discuss the concept and methodology called "delta-aerodynamics" for the ongoing work which allows applying the existing database for the new aeroshape CAL1D with minor corrections