In 1966, Gemini 9 and Gemini 12 exposed fungal spores and viruses directly to space; a 0.4 mm aluminum shield kept fungal spores alive and boosted virus survival 3,000-fold

Early space missions tested microbial survival outside spacecraft without protection. Fungal spores and viruses showed very low survival rates in raw space. A thin aluminum shield dramatically improved survival for both organisms tested. This shielding protected microbes from damaging solar ultraviolet and soft X-ray radiation. These findings continue to inform space exploration and planetary protection protocols.