In a groundbreaking study, NASA explored the effects of long-term space travel on the human body by examining identical twin astronauts, Scott and Mark Kelly. Scott spent 340 days aboard the International Space Station (ISS), while Mark remained on Earth. This unique setup allowed scientists to observe how extended time in space impacts human physiology.
Key Findings from the NASA Twins Study
- Gene Expression Changes: Scott’s time in space led to alterations in gene expression, affecting various bodily functions. Most of these changes reverted to normal within six months after his return.
- Weight Fluctuations: Despite a controlled diet and regular exercise, Scott lost about 7% of his body weight. Conversely, Mark, enjoying Earth’s culinary freedoms, gained approximately 4% of his starting weight.
- Immune System Response: Both twins received flu vaccinations simultaneously—Scott in space and Mark on Earth. Their immune responses were remarkably similar, indicating that vaccines remain effective in microgravity.
- Persistent Changes: Some effects, such as alterations in vision, cognitive functions, and minor chromosomal damage, persisted for at least six months post-mission.
Implications for Future Space Missions
Understanding how space travel affects the human body is crucial for planning extended missions, such as trips to Mars. While many physiological changes are temporary, the study highlights the need for ongoing research to ensure astronaut health during and after long-duration spaceflights.
