Speaker
Description
In recent times, satellite systems boasting thousands of satellites have been launched into orbit. The relatively short lifespan of these satellites, typically lasting only 3-5 years, has lead to increasing chances of in-orbit collisions and overall space cluttering. As the number of space debris experiencing post-mission uncontrolled re-entry rapidly increases, there is growing concern for the threat of ground impact and collisions with operating spacecraft. The complete and controlled demise of spacecraft that have reached the end of their lifespan has therefore risen to the forefront as a matter of utmost importance in sustainable space exploration. This pressing scenario underlines the crucial need for a specialized, sustained monitoring detection system designed to identify and characterize re-entry events from orbit. The information gathered from these observations, coupled with rigorous processing and analysis, has the potential to greatly improve our comprehension of re-entry phenomena. Moreover, it can contribute to refining re-entry models, facilitating precise predictions regarding the timing and location of spacecraft re-entries and associated demise. The work proposed in this abstract is part of the ESA project ”Detection of IR to UV Re-Entry Signatures from Orbit” that has as main objective to design a wide-band orbital detector system to record hundreds of kilometer long streaks emitted from the Earth’s atmosphere due to destructive re-entries of space debris in the IR, Visual, and UV spectrum. One of the main tasks of the project is the simulation of destructive atmospheric re-entry and associated radiative spectra emitted by the fragments, for the purpose of validating the detector system design. The simulation of destructive atmospheric re-entry events is performed with a multi-fidelity tool that has been developed in the context of previous ESA projects. This multi-disciplinary framework combines low- and high-fidelity aerothermodynamics, thermal analysis, 6DOF dynamics and structural analysis in a modular approach to achieve a favourable trade-off between computational cost and accuracy. The present abstract introduces the most recent developments on the tool that focus on improving the accuracy and robustness of the thermal modelling by coupling to an external material response solver. The solver is a modular analysis platform for multiphase porous reactive materials, but it can be run as a simple Fourier heat transfer code. In the coupling methodology, for each trajectory point, the reentry code provides information on the shape of the fragments, as well as surface convective heating, to the material
response solver. The latter handles the simulation of the heat transfer problem within the solid, with a surface energy balance being solved at the wall boundary of each fragment, i.e., the solid-fluid interface, accounting for convection, conduction and radiation. The improved modelling of the surface temperature distribution of the fragments is then used to calculate the spectral emissions to be detected by the sensor.
Summary
Aerothermodynamic, material response and radiation modelling for the detection of demising spacecraft during re-entry
