Spacecraft Fire Safety ─What Are the Fire Safety Standards in Different Gravitational Environments?─

Currently, on the International Space Station (ISS), astronauts stay for extended periods and conduct various experiments. Additionally, the Artemis program plans to construct a residential area on the lunar surface, where crews will stay for long durations. In these environments with different gravity levels from Earth (0G in orbit and 1/6G on the lunar surface), research is being conducted to understand how solid materials burn to ensure fire safety during long-term manned space activities. The photo shows the result of a combustion experiment on filter paper conducted using the Solid Combustion Experiment Module (SCEM) on the ISS. Ignition starts from the far right, and a unique phenomenon of microgravity is observed, where the flame becomes round and meanders as it spreads. By understanding the conditions under which fire spreads, we can establish fire safety policies.