How Long-Term Space Travel Affects the Human Body
Spending extended periods in space can dramatically alter an astronaut’s muscles, bones, brain, and even gut bacteria. While missions aboard the International Space Station (ISS) have provided key insights into these changes, longer missions—such as future journeys to Mars—will present even greater challenges.
The Impact of Microgravity on Astronauts
Astronauts like Frank Rubio, who spent 371 consecutive days in space, and Russian cosmonaut Valeri Polyakov, who holds the record at 437 days, have helped scientists study the physical toll of prolonged weightlessness. Recently, cosmonauts Oleg Kononenko and Nikolai Chub completed 374 days in orbit, pushing the limits of human endurance in space.
Muscle and Bone Loss
One of the most well-documented effects of microgravity is muscle atrophy and bone density loss:
- Muscle loss: Without gravity, the muscles responsible for posture and movement—such as those in the back, neck, calves, and quadriceps—begin to weaken. After just two weeks, astronauts can lose up to 20% of their muscle mass, and over three to six months, this loss can reach 30%.
- Bone density decline: The lack of gravitational force leads to calcium loss from bones, making astronauts more susceptible to fractures upon returning to Earth.
To combat these effects, astronauts rely on rigorous exercise routines, using specialized resistance machines and treadmills on the ISS. However, for future deep-space missions, lighter and more compact exercise equipment will be required.
Preparing for Deep-Space Missions
With NASA and other space agencies planning missions to Mars, where astronauts may spend 1,100 days in space, understanding and mitigating these health risks is crucial. Rubio’s participation in studies on exercise efficiency in microgravity will provide valuable insights for future spacefarers.
As research continues, scientists hope to develop new countermeasures to keep astronauts healthy and strong—not just for long missions in low Earth orbit, but for the next frontier of human space exploration. 🚀
