Space travel presents extreme challenges to the human body, affecting everything from the immune system to muscle function. The two primary threats astronauts face are weightlessness and radiation exposure.
The Effects of Weightlessness
🚀 Weakened Immune System
- Long-duration space missions weaken the immune system, making astronauts more vulnerable to infections—even from normally harmless bacteria.
🦴 Bone Loss and Fractures
- Without regular countermeasures, astronauts lose 1-2% of bone density per month, significantly increasing the risk of fractures.
🩸 Lower Blood Pressure and Anemia
- Blood pressure drops on extended missions, leading to anemia, which can cause dizziness and fatigue.
💪 Muscle Shrinkage
- Space travel can weaken muscles by up to 40%, with leg muscles being particularly affected. This is why returning astronauts often struggle to walk and stand.
👁️ Impaired Coordination
- The connection between vision and movement can deteriorate, making tasks that require precise coordination more difficult.
❤️ Irregular Heartbeat
- The heart’s rhythm becomes irregular, and its pumping capacity may be reduced, potentially leading to long-term cardiovascular issues.
The Effects of Space Radiation
🌞 Radiation-Induced Nausea
- High radiation exposure, such as from a solar flare, can cause acute radiation sickness, leading to nausea and vomiting.
🧬 Reduced Sperm Quality
- Experiments on mice show a 90% decrease in sperm count after 91 days in space, suggesting potential fertility risks for long-term human space travel.
🎗 Increased Cancer Risk
- A round-trip mission to Mars is estimated to raise the lifetime cancer risk by 3%, due to prolonged exposure to cosmic radiation.
Looking Ahead
As space agencies and private companies push the boundaries of human spaceflight, developing effective countermeasures against weightlessness and radiation will be crucial for the success of long-duration missions, including those to the Moon and Mars.
