Simulation of Dynamic Control Environments of the In-Air-Capturing Mechanism

A few years ago, a new, innovative approach for the return of non-SSTO reusable space transportation vehicles has been proposed by DLR: The winged stages are to be caught in the air and towed back to their launch site without any necessity of an own propulsion system. This patented procedure is called in-air-capturing. The performance gain by this advanced method shows a possible increase in delivered payload between 15 % and 25% or allows for significantly reducing the size of a reusable system without any loss in payload mass. The paper gives a brief description of the proposed in-air-capturing method based on latest numerical simulations data. A newly designed capturing mechanism is described and some results of a static stress analysis are presented. The preliminarily sized parts of this mechanism are used for a simplified simulation of the dynamic shock reactions. Suitable homologous models with a limited number of discrete elements are implemented in a dynamic system simulation tool taking into account the separate component masses, the spring stiffnesses and the damping coefficients. The dynamic environment is analyzed for two load cases and potential design improvements are discussed