Speakers
Description
Ionizing radiation is a key limitation for long-duration space missions, as traditional shielding materials are cost inefficient for missions with strict mass constraints, especially for future exploration scenarios such as sustained lunar missions and beyond. Additionally, while widely used shielding materials in space applications like aluminum, titanium, and hydrogen-rich polymers like polyethylene, provide effective primary protection, they can also give rise to secondary radiation when interacting with high-energy particles. This has prompted interest in complementary, biologically inspired approaches to radiation protection. In particular, melanin, which is commonly found in radiation-resistant microorganisms, has been proposed as a potential shielding component.
In this study, we assessed radiation effects behind aluminum and titanium shields using Bacillus subtilis DNA repair–deficient mutants as biological indicators. In parallel, melanin was incorporated into aerogels to evaluate its performance as part of a lightweight shielding material. While conventional shielding materials led to reduced spore survival, indicating secondary radiation effects, melanin-loaded aerogels improved survival under X-ray exposure compared to controls. These findings suggest that melanin-based composites could complement existing shielding strategies and demonstrate the usefulness of biological assays for evaluating radiation protection concepts in space applications.