New Study Reveals Long-Term Heart Damage Risks For Astronauts Traveling To Mars

Phys.org Science•Published: Oct 15, 2026 04:30 AM IST

Researchers from the Medical College of Wisconsin have published a study in PLOS ONE detailing the severe long-term cardiovascular risks astronauts may face during deep-space missions to Mars. By simulating radiation and weightlessness on rats, scientists discovered that cosmic radiation exposure leads to progressive perivascular fibrosis, a condition that significantly increases the risk of heart attacks over time.

Experimental Methodology: Researchers used NASA's hindlimb unloading protocol to simulate microgravity and the 'simGCRsim' at Brookhaven National Laboratory to replicate deep-space radiation.
Cardiac Findings: Exposure to 1.5 gray of radiation caused scar tissue to form around coronary vessels, which doubled in size 270 days post-exposure, constricting blood flow.
Delayed Health Impact: Even at lower radiation doses equivalent to a three-year Mars mission, 83% of subjects developed heart scarring a year later, suggesting long-term health consequences for humans.

The Context & Background

This study addresses the critical knowledge gap regarding how deep-space environments affect human physiology beyond Earth's protective atmosphere. Because long-term human testing is unethical, researchers utilized middle-aged rats to model the biological impact of radiation and weightlessness on career-aged astronauts.

Key takeaway:These findings suggest that the health toll of deep-space travel may not manifest until decades after a mission, potentially forcing space agencies to rethink shielding technology and astronaut medical monitoring. This research serves as a cautionary baseline for the long-term viability of human interplanetary exploration.

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