A study led by UC San Diego's Sanford Stem Cell Institute reveals that human hematopoietic stem and progenitor cells (HSPCs) undergo accelerated aging during spaceflight. Using AI-enabled nanobioreactors aboard the International Space Station across multiple missions, researchers observed reduced regenerative capacity, increased DNA damage susceptibility, and telomere shortening indicative of cellular aging. These findings have profound implications for astronaut health during extended missions and provide insights into aging and disease pathology on Earth.