R.J.B. Cordero
MelaTech,
United States
Keywords: melanin, radiation shielding, polylactic acid, radioprotection
Summary:
Ionizing radiation remains one of the most persistent challenges in space exploration and satellite operations. It degrades polymers, electronics, and structural materials; imposes engineering and economic constraints on mission design; and poses serious risks to astronaut health. Radiation also damages critical assets required for sustained human activity in space, including food and pharmaceuticals. Although materials capable of shielding ionizing radiation exist, they carry major limitations. Heavy metals must be launched from Earth—adding mass and cost—and they generate secondary ionizing radiation, creating additional hazards. To expand the toolbox of materials that can protect against ionizing radiation, we can look to nature and ask how biology has solved this problem. Doing so leads us to melanins: complex, dark, multifunctional polymers with unique physicochemical properties, found across animals, plants, fungi, and bacteria. In humans, melanin protects skin against UV radiation, but in fungi it provides protection far beyond UV. The discovery of melanized black fungi thriving inside the damaged Chernobyl nuclear reactor highlighted melanin’s extraordinary radioprotective capabilities and inspired subsequent studies showing that fungal melanin can protect against UV, X-rays, and particulate ionizing radiation. Black fungi have even survived outside the International Space Station, and fungal melanin has been shown to protect yeast from spaceflight effects. Together, these findings position melanin as a compelling bio-derived radiation-shielding material. In this presentation, I will present the performance of melanin-based biocomposites directly in Low Earth Orbit. Melanin–PLA composites exposed for approximately six months on the exterior of the International Space Station showed significantly reduced mass loss, minimized radiation-induced surface wrinkling, and enhanced shielding of underlying materials, demonstrating that fungal melanin improves the stability and radiation resilience of polymers in the space environment. MelaTech is now addressing the historic barriers that prevented melanin from becoming a practical engineering material, including high production costs and limited availability. We have developed a scalable fungal biomanufacturing platform that produces high-purity melanin at industrial quantities and are integrating melanin into multiple polymer systems to create lightweight, sustainable, radiation-resilient materials for aerospace, defense, and terrestrial applications.