Speaker
Description
The accurate prediction of spacecraft demise behavior during atmospheric re-entry is essential for assessing ground casualty risk and supporting Design-for-Demise strategies. This paper presents recent developments introduced in the CNES Debrisk software version 4, focusing on improved aerothermal fidelity through geometric shadowing effects and enhanced surface chemistry modeling.
A first major improvement concerns the implementation of object shading effects through the explicit definition of primitive positions and orientations within the spacecraft assembly. Previous modeling approaches assumed simple exposure conditions for individual components: only objects at the interior of other objects were full shielded from the flow. The upgraded Debrisk framework now incorporates the spatial configuration and attitude of geometrical primitives, enabling the computation of localized flow exposure and blockage effects during re-entry. This enhancement allows a more realistic estimation of heat flux distribution, temperature evolution, and component survivability, particularly for densely packed spacecraft configurations and complex geometries.
The second major novelty is the introduction of a catalycity model for surface heat transfer prediction. The implemented model accounts for catalytic recombination effects occurring at material surfaces under high-enthalpy atmospheric conditions, which can significantly influence convective heating levels during hypersonic flight. By incorporating material-dependent catalytic behavior into the aerothermal calculations, the updated methodology improves the prediction of wall heat fluxes and thermal response for a broad range of spacecraft materials.
Together, these developments substantially enhance the physical realism of the Debrisk software while preserving its applicability to engineering-level demise analyses. Preliminary assessments demonstrate the importance of both geometric shadowing and catalytic effects in determining component survivability and breakup behavior during atmospheric re-entry. The new capabilities provide improved support for spacecraft design optimization and future compliance with debris mitigation and casualty risk requirements.