Why kidneys are damaged in space. According to scientists, astronauts will experience kidney problems for two reasons. The main cause is galactic cosmic rays (GCR), or simply cosmic radiation. Additionally, microgravity has a negative impact. Scientists report this in the journal Nature Communications. You might think of astronauts who spend extended periods on the ISS without kidney issues. In reality, the ISS is not fully exposed to GCR, as it is located in low Earth orbit under the protection of the Earth’s magnetic field. However, even on the ISS, an astronaut receives the same dose of radiation in a year as a nuclear power plant worker does in five years. Currently, the only people who have been fully exposed to GCR are the astronauts who participated in NASA’s Apollo missions, meaning the 24 individuals who went to the Moon. However, these journeys never lasted longer than 12 days. A mission to Mars would require spending several years in space. As a result, astronauts would receive an enormous dose of radiation.
What happens to the kidneys in space? As mentioned earlier, scientists have previously determined what happens to blood in space and human DNA, as well as other body systems. For example, researchers recently discovered a phenomenon known as “space migraine,” which astronauts seldom discuss. However, kidneys have not received much attention. Therefore, it was not anticipated that these organs could be severely damaged by radiation.
In a recent study, scientists analyzed kidney function and related biomarkers in more than 60 astronauts. Additionally, they thoroughly examined the kidneys of rodents that had been on the International Space Station (ISS). They also simulated the effects of long space journeys by bombarding mice and rats with a dose of radiation similar to what astronauts would receive during a trip to Mars.
As it turns out, serious changes in the kidneys can occur in astronauts in less than a month of being in space. These changes will lead to progressive and irreversible loss of kidney function. However, astronauts will experience symptoms much later.
The issue is that the kidneys are organs whose problems become noticeable only in the later stages. For example, kidneys can lose 75% of their function without a person feeling any symptoms, or symptoms may just begin to appear. Therefore, it is quite possible that astronauts will feel health problems not in space, but upon returning to Earth, and these issues will be irreversible. In fact, they could become disabled.
But that’s not all — another problem is the formation of kidney stones, and astronauts will face this issue much earlier than kidney failure. Scientists have long known that the risk of developing kidney stones in space is 14 times higher. Previously, this problem was associated with bone demineralization due to microgravity. Now, however, scientists believe that kidney failure, which gradually develops in astronauts, is partly to blame.
People won’t be able to fly to Mars? The conclusions drawn so far are only preliminary, as they are primarily based on experiments with rats in laboratory conditions. If confirmed, long-duration space flights will become impossible without addressing this issue. It may not be possible to protect the kidneys from radiation, but it is possible that scientists could develop drugs to mitigate its negative effects. However, solutions to other health problems, both mentioned above and less serious ones like nail detachment, have not yet been found. Therefore, a manned flight to Mars is unlikely to take place in the near future.
Comment: Even after reading this essay by Gregory Roitman, I’d still like to spend a couple of days in space, either on the ISS or on a capsule beyond the ISS. But only a few days. I’d pass on one of those up to the edge of space for a few minutes and down again.
I wonder how much thought and effort Musk is putting into this problem of human physiology. Living in lunar lava tubes may allow longer stays there, but for how long? Colonizing Mars will be a far more difficult challenge.
This doesn’t mean we should give up on manned space flight. If nothing else, it sparks the human imagination and instinct to explore. But we can do much of that through robotic exploration. Look at the Perseverance rover and the Ingenuity helicopter. Hell, the Voyager missions still get me excited.
TTG
https://www.nasa.gov/wp-content/uploads/2009/07/284275main_radiation_hs_mod3.pdf?
“The conclusions drawn so far are only preliminary, as they are primarily based on experiments with rats in laboratory conditions.”
So the author threw some clickbait out there based on ‘lab rat’ experiments. Thanks.
Fred,
In addition to the lab rats, they analyzed kidney function and related biomarkers in more than 60 astronauts and thoroughly examined the kidneys of rodents that had been on the ISS.
My dad was one of the foremost Cosmic Ray physicists of his day. (Discontinued his research in 1983 or so and became vice chancellor of a university). He said distant space travel was probably doomed to be a sci-fi writer’s fantasy because Cosmic Rays pose such severe health problems. Last time Iooked in the year 2000 or so the highest energy cosmic rays were protons with energies so high they were equivalent to being hit with a tennis ball traveling 100 miles per hour (or 170 km per hour). That’s one infinitesimally tiny proton. Now imagine being bombarded with hundreds of thousands of them. I’d rather not.
Addendum. I should have clarified that those are only the highest energy cosmic rays, not the common garden variety ones.
https://en.wikipedia.org/wiki/Cosmic_ray
I don’t know very much about physics. At all. But if there is a significant amount of energy striking an interplanetary spacecraft via cosmic rays then isn’t that a source of free energy that the designers of such craft should be attempting to tap into?
A two-fer: not only are they shielding the occupants from harm, but are turning that energy into good use.
Cosmic rays pass through the material cover of the space ship and through everything including the human passengers. But they have variable decay rates and where and when they decay no one knows but when they do their decay products are deadly because of their ionization effects. For example, neutral pi mesons have an incredibly small lifetime in their own rest frames. I need to look it up but for instance a plain old neutron in it’s rest frame decays into an electron plus a proton plus a neutrino in about 17 seconds. A neutral pi meson on the other hand has a lifetime of 8 divided by 10 to the 17th power seconds approximately. Compared to which a nanosecond is an eternity. That’s why they are promising therapeutically because if you do the math correctly and measure the distance to a patient’s tumor accurately you can shoot a neutral pion at the patient’s head and it will penetrate effortlessly till it reaches the target point at which point it ineluctably undergoes decay and the decay products damage/destroy the diseased tissue. Same with the spacemen – it’s the decay products which damage tissue, not the cosmic rays themselves.
https://en.wikipedia.org/wiki/Pion
Why “in their own rest frame?” Relativistic time dilation. A prediction of Einstein’s Special Theory of relativity. A particle which has a lifetime of say a nanosecond — how can it even be observed? Because it travels at such a highly relativistic speed (means nearly the speed of light) it may travel through our atmosphere for quite a while as measured in our rest frame, but in it’s own frame it lives for only a billionth of a second. You’d need impossible to obtain reams of data on all the cosmic rays nearing your spaceship, unfortunately, to even begin to realize your very interesting idea.
https://en.m.wikipedia.org/wiki/Time_dilation
Dejah Thoris will have to pine away for my arrival on Mars just a few more years for me until bioengineers successfully develop an implantable bioartificial kidney.