To be honest, I believe in the future of space colonization because I want to believe in it. It’s romantic. It’s adventurous. It’s cool! And, in a worst-case scenario, it’s a way to preserve our species if we doom Earth. Deus ex humana We bail ourselves out, even if we probably don’t deserve it under those circumstances. I’m a big supporter of the Artemis and Gateway programs, which could see construction of a lunar space station begin in 10 years and manned missions to Mars in my lifetime. I dream beyond that, because dreaming is good and healthy. There are countless technical hurdles along the way, but they’re worth tackling in and of themselves. Figuring out which challenges can be overcome will allow us to make scientific progress.
But what if certain challenges were obstacles rather than obstacles, biological rather than technological? What if the problem wasn’t about what we could build, but about who we are? If the obstacles weren’t about time or distance, but about fundamental weaknesses of the human body, it would be a major blow to any future hopes of space colonization. The harmful effects of spaceflight on the human body have been known for a long time: osteoporosis, anemia, weakened immunity, and increased cancer risk. Some problems are caused by microgravity, others by background radiation in space. NASA estimates that astronauts are exposed to 10 million tons of radiation. Up to 6,000 chest x-rays. Astronauts in low Earth orbit, where the International Space Station is located, are partially protected from this radiation by the Earth’s magnetosphere, but are still affected.
In addition to these effects, there are also potentially disastrous effects: Space severely damages our kidneys.
The study has the ominous title “Space Kidney Disease.” Published last week Nature Communicationshas been testing the kidney function of 66 astronauts who stayed on the International Space Station for up to 180 days. This is relatively safe compared to, say, a return mission to Mars, which would last several years and expose astronauts to the more intense radiation of space. But even that limited time took a toll on astronauts. The study found a significant decline in kidney function and an increased risk of kidney stones due to shrinkage of the kidney tubules. You don’t have to be a doctor to know this is bad. And over the long term, the damage could be permanent. The study simulated the effects of longer exposure in mice, but the mice’s kidneys did not recover.
Even more ominous for long-term missions, the effects won’t be apparent until it’s too late to prevent them: “Unless we develop new ways to protect the kidneys, astronauts may make it to Mars but need dialysis on the return journey.” Dr. Keith Shue says:Dr John Myers, lead author of the study, said: “We know that the kidneys are slow to show signs of radiation damage. By the time these signs become evident, it will likely be too late to prevent failure, which would be devastating to the mission’s chances of success.”
NASA is well aware of the need for protection from radiation, especially high-energy galactic cosmic rays, during manned interplanetary missions. Investigating potential solutionsOne way to protect against cosmic radiation is to use a protective mass, i.e. a large spaceship. But this huge spaceship would be too heavy and expensive to launch. Another option is to use materials that would provide more efficient protection without adding weight. Such materials do not exist at the moment. Other ideas, such as force fields or drugs to counter the effects of radiation, are still theoretical. At the moment, there is no way to get to Mars or beyond without exposing astronauts to lethal doses of radiation.
It would be poetic if the limitations that bound us to Earth were not distance or time, but our very bodies, but it would make sense: we have evolved and survived for billions of years. hereand just here: this much gravity, this much exposure to radiation, this much temperature and pressure and atmospheric composition. Goldilocks Zone As far as habitability goes, those parameters are not special, they are simply designed for human habitation.
This is not necessarily a death sentence for space exploration and colonization. The same sci-fi brains that can imagine colonizing other planets would easily come up with things like genetic engineering to protect the kidneys from the ravages of space. But there are a lot of very smart people who believe that these and other problems are truly insurmountable and that we will never live on other planets. They may be right! My first reaction is to feel that it is disheartening, but maybe it doesn’t have to be. Rather, knowing that we as a species have to live and die here may be inspiring. It’s not something to be ashamed of. It’s true for every other species so far. And it’s probably a motivation to make the most of what we have, to preserve it, and not ruin it. If we can’t escape an uninhabitable Earth, the only option is to fix it.