Damage to Relativistic Interstellar Spacecraft by ISM Impact Gas Accumulation

As part of the NASA Starlight collaboration, we look at implications impacts with interstellar medium (ISM) on a directed energy-driven relativistic spacecraft. The spacecraft experiences stream MeV/nucleon along forward edge primarily from hydrogen and helium nuclei. accumulation implanted slowly diffusing gas atoms in solids drives damage through meso-scale processes bubble formation, blistering, exfoliation. This results macroscopic changes to material properties and, cases blistering exfoliation, erosion via blister rupture delamination. Relativistic constant velocity will stop similar depth, as predicted by Bethe–Bloch stopping subsequent simulations implantation distribution, leading mixed system that observed within fusion plasma-facing components. However, difference depth near-surface respect direction exposure means previously developed empirical models cannot be used predict formation or onset. In this work, present model local concentration threshold for ISM speeds. Expected effects mitigation strategies are also discussed. same considerations apply Breakthrough Starshot mission.