Leonid Bussler

Comparison of Return Options for Reusable First Stages

DLR’s Space Launcher Systems Analysis division analyzes generic Reusable Launch Vehicles for missions to Geostationary Transfer Orbit. The launcher configurations consist of a reusable first stage and two expendable upper stages. For the reusable first stage different separation Mach numbers are considered. The return options considered are stage fly-back and stage in-air capturing. Based on mass estimation, analysis of ascent and descent aerodynamics as well as ascent and reentry trajectory optimization first results for the return options stage fly-back and in-air capturing are presented.

Advanced Simulations of Reusable Hypersonic Rocket-Powered Stages

After successful completion of the MRR, technical progress of the SpaceLiner ultra-high-speed rocket-propelled passenger transport is achieved in Phase A conceptual design work. Following geometry refinement the structural design is maturing based on extensive trade-offs. Aerodynamics are investigated by numerical CFD-simulations of the two winged stages and will be supported by windtunnel tests. Aerodynamic control surfaces of the passenger cabin and rescue capsule and its subsystems are defined. Alternative options for the capsule with innovative morphing shapes are critically investigated taking into account system aspects, structural design, and advanced CFD-simulations. Potential intercontinental flight routes, considering range-safety and sonic boom constraints as well as good reachability from major business centers, are evaluated and flight guidance schemes are established. Extensions to this trajectory model are implemented to investigate the attitude dynamics and related controllability issues of the asymmetric launcher configuration. The space transportation role of the SpaceLiner concept as a TSTO-launcher is now addressed in technical detail.

SpaceLiner Cabin Escape System Design and Simulation of Emergency Separation from its Winged Stage

The SpaceLiner is a visionary concept of a hypersonic passenger transportation system with two parallel winged stages based on rocket propulsion. This fully reusable system has been studied by the German Aerospace Center (DLR) for over a decade and has entered its project phase A in 2017. Since it is supposed to transport up to 50 passengers on suborbital trajectories, high standards for safety and reliability have to be applied to this system. Hence, an emergency capsule (SpaceLiner Capsule) accommodating the passengers is foreseen that shall safely eject from the SpaceLiner passenger stage in case of a critical emergency. This paper focuses on the separation process and investigates the baseline capsule ejection procedure such as the cabin and separation motor design. Furthermore, the status and recent developments of the SpaceLiner are presented.