In 1983, NASA flew Neurospora bread mold on STS-9 to test its body clock; the rhythm persisted, but faded out in 25% of flight tubes before light restored it

In 1983, NASA conducted research on fungal circadian rhythms aboard the Space Shuttle Columbia, observing the bread mold Neurospora crassa. While some cultures maintained a consistent rhythm under space conditions, others lost this pattern until they were exposed to regular light. This experiment marked an early demonstration of biological clocks operating in microgravity, reinforcing the notion that factors beyond Earth's rotation may influence these rhythms.