What if we’re stuck here?

To be honest, I believe in the future of space colonization because I want to believe in it. It’s romantic. It’s an adventure. It’s cold! It is also, in the worst-case scenario, the way to preserve species if the Earth is destroyed The former god of humanity To save ourselves even if under those circumstances, we may not deserve it. I strongly encourage the Artemis missions and Project Gateway, which could begin construction of a space station orbiting the Moon by the end of the decade, and a manned mission to Mars in my lifetime. Dream beyond, because it’s good and healthy to dream. Along the way there are countless technological obstacles, which are worth tackling in themselves: we advance scientifically by identifying challenges that can be overcome.

But what if some challenges are not obstacles but roadblocks, not technological but biological? If the problem is not what we can build, but what we are? It would be a huge blow to the future hopes of the cosmic diaspora if the obstacles were not about time and distance, but rather about the basic weaknesses of the human body. We’ve long known the harmful effects spaceflight can have on the human body: bone loss, anemia, weakened immune systems, higher cancer risks, and the list goes on. Some problems are caused by microgravity; Others are by space background radiation – NASA estimates that astronauts are exposed to the equivalent Up to 6000 chest X-rays. Astronauts in low Earth orbit, where the International Space Station is stationed, are partly protected from this radiation by the Earth’s magnetosphere, but they also suffer from its effects.

Add to these effects a potentially catastrophic effect: space is dramatically damaging our kidneys.

The study, titled “Cosmic Kidney Disease,” and Published last week in Nature Communications, examines kidney function in 66 astronauts who spent up to 180 days on the International Space Station, which is relatively safe compared to a return mission to Mars, which could last a few years and expose the astronauts to more intense radiation from the depths. space. But even this limited time had a significant impact on the astronauts. The study found a significant decrease in kidney function and an increased risk of kidney stones, as a result of shrinkage of the renal tubules. And this, you don’t need to be a doctor to know that’s a bad thing. The damage can be permanent after enough time. The study simulated the effects of longer exposure on mice, and their kidneys never recovered.

What’s more, the effects don’t start to show until it’s too late to prevent them. “If we don’t develop new ways to protect the kidneys, I would say that even though an astronaut can get to Mars, he or she may need dialysis on the way back.” Dr. Keith Siu said, lead author of the study. “We know that the kidneys are late in showing signs of radiation damage; by the time this becomes clear, it may be too late to prevent failure, which would be disastrous for the mission’s chances of success.”

NASA is well aware of the need for radiation protection, especially high-energy galactic cosmic rays, on any manned interplanetary mission, and it Investigate potential solutions. One way to protect against cosmic rays is through a massive shielding mass: a larger spacecraft. However, launching such a spacecraft would be very heavy and expensive. Another option is to use materials that protect more efficiently without adding weight. These materials do not currently exist. Other ideas, such as force fields or drugs that counter the effects of radiation, remain in the distant theoretical realm. Currently, there is no way to go to Mars or beyond without exposing astronauts to lethal doses of radiation.

It would be almost poetic if the constraints that ultimately keep us grounded were not those of distance and time, but of our bodies themselves. But does it make sense? We have evolved over billions of years to survive hereAnd only here: this amount of gravity, this amount of exposure to radiation, this temperature, pressure and composition of the atmosphere. When we talk about Temperate zone In terms of habitability, there is nothing special about those parameters, they are just those that humans are designed for.

This is not necessarily a death sentence for space exploration and colonization; The same science fiction mind that can imagine colonizing other planets can just as easily envision, I don’t know, genetic engineering to protect our kidneys from the ravages of space. But there are a lot of smart people who believe that these and other issues are truly insurmountable, and that we will never live in other worlds. They could be right! My first reaction is to find that frustrating, but maybe it doesn’t have to be. Maybe it would be exciting instead, to know that we as a species have to live and die here. There’s nothing wrong with that – that’s the case for every other species by now – and perhaps it’s an incentive to make the most of what we have, preserve it, and stop destroying it. If there is no escape from the uninhabitable land, the only option is to repair it.