NASA conducts a variety of tests both on Earth and in space, with the International Space Station (ISS) serving as a crucial platform for such research. These experiments provide insights into human biology in a zero-gravity environment and drive technological advancements. One NASA study explored the long-term effects of spaceflight on human health, complemented by research into short-term impacts. This knowledge becomes increasingly relevant as space exploration transitions to private enterprises like Blue Origin and SpaceX.
Susan Bailey, Professor of Radiation Cancer Biology and Oncology at Colorado State University, led a study on the 2021 SpaceX Inspiration4 mission crew, documenting their telomeres—protective caps on chromosomes likened to plastic tips on shoelaces. Bailey observed that the crew’s telomeres lengthened during their mission but shortened upon return to Earth three days later.
Similar findings were observed in astronaut Scott Kelly, who spent a year aboard the ISS while his twin remained on Earth for comparison. This comparative study aimed to understand the effects of space on human biology. Despite their shorter mission duration, the rapid telomere changes observed in the Inspiration4 crew underscore the immediate impact of space travel on DNA.
Space can rapidly impact your DNA
Susan Bailey, along with her team, participated in NASA’s twin study involving astronaut Scott Kelly and his twin brother in 2015. During this study, Kelly spent a year aboard the ISS while his brother remained on Earth. Numerous investigations were conducted, with Bailey focusing on analyzing Scott’s blood samples taken before, during, and after his space mission. The data revealed that Scott’s telomeres lengthened while in space but significantly shortened upon his return to Earth.
Bailey and her colleague Christopher Mason also conducted a twin study involving mountain climbers who ascended Mt. Everest. Similar to the space study, the climbers experienced noticeable telomere elongation during their ascent, which reversed upon their descent. In contrast, their twin counterparts, who remained at lower altitudes, did not exhibit such drastic changes in telomere length.
Additionally, another study monitored a group of 10 astronauts during a six-month mission aboard the ISS. Bailey and her team compared them with a control group on Earth, matching for sex and age. As anticipated, the astronauts who traveled to space experienced significant telomere shortening compared to their Earth-bound counterparts.
The Importance of Telomere Length
Telomeres naturally shorten over time due to factors like stress, inflammation, and aging. Additional influences such as pollution, smoking, and physical activity can also impact their length. Astronauts and mountain climbers experience accelerated telomere shortening, highlighting the importance of understanding these processes. While scientists recognize telomere length as a potential indicator for diseases like cancer and dementia, much remains unknown.
Research led by Susan Bailey and her team, including the study of mountain climbers, suggests that factors beyond gravity influence telomere length. Radiation exposure, particularly cosmic radiation in space, likely plays a significant role, as astronauts lack Earth’s atmospheric protection. Higher altitudes also expose individuals to increased cosmic radiation. Further investigation in this area is crucial for preparing human physiology for space exploration and potential planetary colonization.
