The Impact of Space Travel on Human Biology

As the world prepares for a new era of human spaceflight, researchers are working to understand the effects of space travel on the human body. With private and commercial spaceflight providers entering the market, missions are becoming longer and more diverse, with people of different ages, ethnicities, and health status experiencing the extreme environment of space. As a radiation cancer biologist, I have spent years studying the impact of spaceflight on human health, and my latest research offers the most comprehensive look at spaceflight health since NASA’s Twins Study.

The Twins Study, conducted in 2019, examined the effects of a year-long mission on the International Space Station on astronaut Scott Kelly and his identical twin brother, Mark Kelly, who remained on Earth. The study found that Scott’s telomeres, the protective caps at the end of chromosomes, lengthened during his time in space, but shortened after his return to Earth. This was unexpected, as telomeres typically shorten with age due to stress. The study also found that a cohort of 10 astronauts on six-month missions had longer telomeres during spaceflight, but shortened telomeres after their return.

In a separate study, I examined the telomeres of twin high-altitude mountain climbers and found that their telomeres lengthened during the climb, but shortened after they descended. This suggests that it’s not the microgravity of space that causes telomere length changes, but rather increased radiation exposure.

Recently, I studied the telomeres of the crew on board SpaceX’s 2021 Inspiration4 mission, which had an all-civilian crew with ages spanning four decades. The results showed that all crew members’ telomeres lengthened during the mission, and three of the four astronauts exhibited telomere shortening after their return to Earth. This is significant, as the mission lasted only three days, indicating that even short trips to space can cause changes in telomere length.

The findings suggest that telomeres are sensitive to oxidative stress and chronic damage from space radiation, which may contribute to the telomeric responses observed in astronauts. However, the long-term health impacts of these changes are still unknown and require further research.

In another study, I found that the Inspiration4 crew, as well as Scott Kelly and the high-altitude mountain climbers, exhibited increased levels of telomeric RNA, which contributes to telomere structure and helps them do their job. This suggests that telomeres are being damaged during spaceflight.

The research also explored the telomeres of plants flown in space and found that, unlike humans, they did not have longer telomeres during their time on the International Space Station. However, they did increase their production of telomerase, the enzyme that helps maintain telomere length. This suggests that plants may be more naturally suited to withstand the stressors of space than humans.

Understanding the impact of space travel on human biology is crucial for long-term human survival in space. As we look ahead to returning to the Moon and exploring other planets, it’s essential to understand how to help astronauts stay healthy during and after their missions. This research provides valuable insights into the effects of spaceflight on human health and will inform the development of strategies to mitigate its impacts.

Key Takeaways:

• Telomeres lengthen during spaceflight, but shorten after return to Earth
• Telomeres are sensitive to oxidative stress and chronic damage from space radiation
• Even short trips to space can cause changes in telomere length
• Plants may be more naturally suited to withstand the stressors of space than humans
• Further research is needed to understand the long-term health impacts of space travel on human biology

Historical Context:

The concept of space travel and its impact on human biology has been a topic of interest for decades. The first human spaceflight was achieved by Soviet cosmonaut Yuri Gagarin in 1961, and since then, numerous space agencies and private companies have sent humans to space. However, the effects of space travel on the human body were not fully understood until the NASA Twins Study in 2019. The study, which examined the effects of a year-long mission on the International Space Station on astronaut Scott Kelly and his identical twin brother, Mark Kelly, revealed that Scott’s telomeres lengthened during his time in space, but shortened after his return to Earth. This study sparked a renewed interest in understanding the impact of space travel on human biology.

The article discusses the latest research on the impact of space travel on human biology, specifically focusing on the effects of telomeres, which are the protective caps at the end of chromosomes. The study found that telomeres lengthen during spaceflight, but shorten after return to Earth, suggesting that they are sensitive to oxidative stress and chronic damage from space radiation. The research also explored the telomeres of plants flown in space and found that they did not have longer telomeres during their time on the International Space Station, but increased their production of telomerase, the enzyme that helps maintain telomere length.

Summary in Bullet Points:

• Telomeres lengthen during spaceflight, but shorten after return to Earth • Telomeres are sensitive to oxidative stress and chronic damage from space radiation • Even short trips to space can cause changes in telomere length • Plants may be more naturally suited to withstand the stressors of space than humans • Further research is needed to understand the long-term health impacts of space travel on human biology • The study suggests that telomeres are being damaged during spaceflight, which may contribute to the telomeric responses observed in astronauts • The research provides valuable insights into the effects of spaceflight on human health and will inform the development of strategies to mitigate its impacts • Understanding the impact of space travel on human biology is crucial for long-term human survival in space