A presentation by Pam Graham of Space Oasis Delft, with Konstantinos Chatzipapas and Marc van Ligtenberg, was scheduled for 17 June 2026 at ESA’s European Space Radiation Shielding Workshop at ESTEC. The study used custom OpenGate Monte Carlo radiation-transport simulations to evaluate water-ice shielding integrated into inflatable structures against galactic cosmic rays and solar particle events. Preliminary configurations reduced equivalent dose rates by up to 90%, with performance dependent on ice thickness and membrane composition.[1][2]
For the Lunar Ark, the result validates water as a dual-use strategic mass: life support reserve, thermal-control medium, and hydrogen-rich radiation shield. Ice can produce fewer secondary particles than conventional high-atomic-number structural materials, while inflatable structures reduce delivered mass. However, the 90% figure is preliminary and Mars-focused; lunar deployment must address vacuum stability, micrometeoroids, thermal cycling, sublimation control, excavation yield, and uneven polar-ice access. Earlier Mars habitat analyses indicate that 2 metres of water reduced modeled dose by about 58%, while 3 metres achieved about 72%, demonstrating that geometry and thickness strongly govern performance.[7]
Ark action: establish water-ice shielding as a core trade-study path for permanent lunar habitats; require simulations using lunar galactic-cosmic-ray and solar-particle environments, quantify dose by habitat location and mission duration, and test membrane coupons and ice-retention systems under vacuum and thermal cycling. Track the ESA work for validated material configurations, independently reproduce the OpenGate results, and reserve polar-prospecting and water-processing capacity sufficient to support shielding rather than life support alone.[1][2]