Impact of material and surface properties on thermo-mechanical coupling in laser-based orbit modification of space debris

Kurzfassung

The rapidly increasing amount of space debris is a critical problem of modern and future space infrastructure. Repetitively pulsed high energy lasers are frequently discussed as a technological option for the remotely based removal of multiple small space debris objects from the low Earth orbit (LEO) by recoil from laser ablation. Aiming for a realistic assessment of the concept’s efficiency in debris mitigation, awareness of thermal constraints is needed. In our study, we employ finite element analysis (FEM) of the laser ablation process regarding imparted momentum from laser-ablative recoil as well as laser-induced heat inside the target after ablation. The simulation results are underpinned by observations of velocity change and temperature increase from single pulse laser irradiation of cm-sized targets in a drop experiment in vacuum (10 ns pulse duration, 1064 nm wavelength, 60 J nominal pulse energy) from the nhelix laser of the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. Both polished and sandblasted samples of common space debris materials like aluminum, copper, steel, and titanium are employed in our analysis. Our findings suggest that exhaustive target reconnaissance is required to ensure operational safety in laser-based orbit modification regarding predictability of the modified trajectory as well as thermal constraints in target heating.