Health Risks Assessed

A Mars mission poses unprecedented health challenges. Beyond radiation, astronauts face bone density loss of 1 to 2 percent per month in microgravity, muscle atrophy, fluid shifts that cause vision problems, and the psychological toll of extreme isolation for two to three years with no possibility of rescue.

Mars's surface gravity is only 38% of Earth's — better than microgravity but potentially insufficient to prevent long-term health effects. Artificial gravity during transit, created by spinning the spacecraft, is one proposed solution but adds engineering complexity.