They called for the sexual health of astronauts to be closely monitored on their return from future deep space missions, noting that certain antioxidants may help to counteract the ill-effects by blocking harmful biological processes.

Since the dawn of the space age, scientists have explored the impact on human physiology of weightlessness and cosmic radiation – the high-energy particles, X-rays and gamma rays that stream from stars and other heavenly bodies.

The work has led to the introduction of preventive measures, including special exercise regimes on the International Space Station (ISS) to protect astronauts from wastage of bones and muscles.

In a series of experiments, dozens of rats were suspended in harnesses at a 30-degree angle and exposed to simulated galactic cosmic rays at Nasa’s Space Radiation Laboratory in New York.

“Collectively, these results suggest that neurovascular function of the erectile tissues may be impaired throughout the remainder of the astronauts’ sexual health span following return to Earth from prolonged deep space exploration,” the authors write.

Treatment with specific antioxidants appeared to improve tissue function after exposure to galactic cosmic rays, suggesting male astronauts bound for Mars need not be too deflated.

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