In 1984, NASA left Bacillus spores in space for nearly 6 years; after LDEF returned to Earth, 1–2% of the exposed spores were still alive

During an extensive six-year voyage aboard the LDEF satellite, soil bacteria spores demonstrated remarkable resilience, surviving the rigors of space including vacuum, extreme temperatures, and cosmic radiation. The spores shielded from sunlight exhibited notably better survival rates, suggesting the intriguing possibility that life could travel between planets with minimal protection. These insights are pivotal for enhancing spacecraft sterilization protocols and deepening our understanding of panspermia.