Abstract EANA2026-28

Background and Objectives As the Artemis program and private-sector activities prepare for the prospect of a sustained human presence on the Moon, it is vital to understand the limits of terrestrial life in terms of survival. This is performed to ensure planetary protection. The existence of a "critical data gap" is attributed to the fact that the fundamental knowledge acquired from ISS missions such as "Tanpopo" was obtained within the Earth's protective magnetosphere. The objective of the Daisy mission is to address this deficit by conducting the inaugural microbial space exposure experiment directly on the lunar surface. This study evaluates the resilience of human-introduced microbes to integrated lunar stressors, including vacuum, extreme thermal cycling, and solar UV, thereby providing essential baseline data for the development of international planetary protection standards and future space agriculture development.

The Daisy Exposure Payload The development of "Daisy," a compact, passive exposure system for the lunar polar region, was conducted. The system was engineered to be entirely passive, requiring no power or active communication. This is achieved by leveraging TRL 6 components from the Tanpopo missions. The result is a maximization of reliability while minimizing the operational burden on the host mission.

System Design and Apparatus Overview The apparatus comprises three primary components: an Exposure Stand (ES), Exposure Panels (EPs), and Exposure Units (EUs). The 1.2-m ES is a freestanding pole that is designed for handling by astronauts during EVA. Two panels, EP1 and EP2, create contrasting conditions: EP1 is positioned at the top in direct sunlight, while EP2 is placed near the surface in the shadow of local topography to examine low-temperature effects. Each EP contains three duralumin EUs featuring an MgF₂ window transparent to UV (>110 nm) and a 0.3 µm SUS filter to enable vacuum exposure while preventing microbial escape.

Environmental Test Results The structural and functional durability of the Daisy prototype was verified through rigorous environmental testing. Random vibration tests (14.1 Grms) confirmed launch resilience without damage to the MgF₂ windows or unit frames. Furthermore, vacuum thermal cycling (-150°C to +70°C) and a 170-h cryogenic soak in liquid nitrogen (-196°C) demonstrated that all mechanical interfaces—including clasps, legs, and the pole extension—remain fully functional. These results confirm that the Daisy payload is technically prepared for the Artemis IV mission to provide critical insights into the endurance of terrestrial organisms in deep space.