Deployable Decelerator with Flexible Thermal Protection System for a 35 kg Class Micro Mars Lander: Design, Simulation, and Full-Scale Demonstration

Kurzfassung

This work presents a semi-rigid deployable decelerator with a flexible Thermal Protection System (TPS) for a Micro Mars Lander (MML) with a total mass of approximately 35 kg. The mission concept incorporates a payload carried by a penetrator that anchors itself in the ground through its mass and impact velocity at touchdown; consequently, the decelerator requirements are derived from the penetrator constraints and mission profile. Mechanical and thermal loads along the trajectory are calculated using an internal DLR code. The concept features an umbrella-inspired deployable TPS with folding struts and telescopic high-temperature ceramic elements, enabling an increased drag area while maintaining compact stowage. The present study focuses on the design, manufacturing, and demonstration of the flexible TPS element spanning the deployable structure. A carbon-fiber fabric weave with high-temperature capability is selected as the primary material for the TPS architecture. Structural performance is evaluated using explicit finite-element analysis simulations with LS-DYNA using the *MAT_249 reinforced thermoplastic material model. Boundary conditions are derived from the peak dynamic pressure during Martian atmospheric entry, and multiple load cases are assessed to quantify first principal stresses and global displacements for different fabric layer configurations while accounting for the elevated thermal environment. To advance the concept toward practical implementation, the system design is translated into a full-scale (1:1) mock-up demonstrator. The mechanism, primarily manufactured from aluminium components, enables verification of deployment kinematics, packaging efficiency, and the interface between the flexible TPS and the load-bearing arms. Demonstrator testing shows promising results regarding reliable deployment behaviour and structural compatibility of the fabric, while highlighting key challenges related to manufacturing and assembly, integration, and testing (AIT). The demonstrator establishes the experimental basis for subsequent aerodynamic testing, characterization of fabric and seam load paths, and investigation of permeability effects. The results demonstrate the feasibility of a lightweight deployable fabric TPS for low-ballistic-coefficient Mars micro landers and highlight its potential as a scalable EDL solution.