Astronauts on a future mission to Mars may face a serious health risk that could jeopardize their journey: kidney failure, according to recent research published in Nature Communications. While kidney issues are not typically considered one of the primary dangers of space travel, this study reveals that the extreme conditions of a mission to Mars could alter the structure and function of astronauts’ kidneys, potentially leading to permanent damage.
The damage would stem from exposure to Galactic Cosmic Radiation (GCR), high-energy particles from the rest of the galaxy. Normally, the Earth’s magnetic field absorbs these particles, providing protection on the ground and partially shielding astronauts in low-Earth orbit. However, on a lengthy two-year round trip to Mars and back, astronauts would be exposed to significant amounts of GCR, which could damage their organs and DNA.
“If we don’t develop new ways to protect the kidneys, I’d say that while an astronaut could make it to Mars they might need dialysis on the way back,” said Keith Siew, a researcher at University College London’s (UCL) Department of Renal Medicine. “We know that the kidneys are late to show signs of radiation damage; by the time this becomes apparent, it’s probably too late to prevent failure, which would be catastrophic for the mission’s chances of success.”
The potential health issues related to space travel are well-documented, including bone mass loss and kidney stone development. However, only a small number of astronauts, specifically those who travelled to the moon, have been exposed to the full force of GCR, and only for short durations. This has left a gap in our understanding of the long-term impacts of GCR on the human body—until now.
In their study, researchers analyzed samples from humans and mice involved in over 40 low-Earth missions. They also experimentally tested the effects of a Mars mission equivalent dose of GCR on mice and rats. The findings showed that the kidneys of both mice and humans are “remodeled” by space conditions, leading to changes in how the kidneys process salts and an increased likelihood of kidney stones. These changes may result from microgravity or a combination of GCR and microgravity. Notably, the kidneys of mice exposed to conditions equivalent to a two-and-a-half-year trip to Mars were permanently damaged.
“We know what has happened to astronauts on the relatively short space missions conducted so far, in terms of an increase in health issues such as kidney stones. What we don’t know is why these issues occur, nor what is going to happen to astronauts on longer flights such as the proposed mission to Mars,” Siew explained.
The researchers emphasize the critical need to address this issue before sending astronauts to Mars. “Our study highlights the fact that if you’re planning a space mission, kidneys really matter. You can’t protect them from galactic radiation using shielding, but as we learn more about renal biology it may be possible to develop technological or pharmaceutical measures to facilitate extended space travel,” said Stephen B. Walsh, a professor at UCL’s Department of Renal Medicine.
Interestingly, the research also suggests potential Earth-bound applications. “Any drugs developed for astronauts may also be beneficial here on Earth; for example by enabling cancer patients’ kidneys to tolerate higher doses of radiotherapy, the kidneys being one of the limiting factors in this regard,” Walsh noted.
As the dream of a manned mission to Mars inches closer to reality, ensuring the health and safety of astronauts becomes ever more crucial. This study underscores the importance of developing protective measures for the kidneys to secure the success of future deep-space missions.
