Mission-Dependent Sequential Simulation for Modeling and Trajectory Visualization of Reusable Launch Vehicles

The multibody modeling and visualization of reusable launch vehicles is a challenging task due to their variable structure regarding component separation and engine cutoffs during ascent and descent. However, the number of states within a MODELICA-based multibody model has to remain constant during a simulation. Therefore, the variable structure of launch vehicle models is often considered by using time- and state-dependent conditional statements and separation components. Such an approach can lead to a higher number of equations in the model and to a higher model complexity, respectively. In this paper, a mission-dependent sequential simulation approach for the modeling and trajectory visualization of launch vehicle systems is introduced. Here, the system is divided into characteristic phases, which are modeled with the DLR LauncherApplications Library capitalizing its modular, reusable and user-friendly structure to maintain compatibility between phases and to decrease the overall model complexity and the number of equations.