Flexible PVA/BA gel for passive radiation shielding in spacesuit applications beyond LEO

Protection of astronauts from intense space radiation during long-term missions to the Moon or Mars remains a critical challenge. With space agencies planning permanent lunar bases as gateways for deep-space exploration, enhancing radiation shielding in spacesuits during extravehicular activities (EVAs) is essential. This study explores the feasibility of integrating poly(vinyl alcohol) (PVA)-based gels as an intermediate shielding layer between the pressure bladder garment (PBG) and the liquid cooling and ventilation garment (LCVG), without altering suit geometry or increasing layer thickness. Due to their high water content, PVA-based gels combine flexibility, softness, and ductility with effective radiation attenuation. Experimental analyses compared the physical and mechanical properties of PVA gels to nylon, the primary material of PBG and LCVG. The gels exhibited similar density and thermal conductivity but demonstrated superior deformability, achieving elongations up to ∼65% despite a lower Young’s modulus. Numerical simulations performed with the OLTARIS confirmed the shielding potential of the proposed configuration. While protection against Galactic Cosmic Rays (GCR) remained limited due to their high penetration depth, the inclusion of PVA-based gel layers significantly reduced proton doses from Solar Particle Events (SPE), indicating their potential as an effective, lightweight enhancement to current spacesuit designs. • A flexible gel is developed as a lightweight passive radiation shield for EVA suits. • High water content and elongation ensure gel flexibility and ergonomic integration. • Gels exhibit self-healing, recovering mechanical integrity within 48 h after damage. • OLTARIS simulations show limited GCR attenuation but > 60% dose reduction for SPE. • A 1 cm gel layer offers optimal protection - mass balance enhancing astronaut safety.