Can Space Be Hazardous To Your Health?

 

The short answer is, yes.

 

When International Space Station (ISS) crew members Matthew Dominick, Michael Barratt, Jeanette Epps, and Alexander Grebenkin returned from a 235-day mission on Friday, October 25, NASA officials decided to hospitalize them all in a Pensacola facility.  One astronaut (not named for privacy reasons) stayed overnight, while the others were treated and released sooner, and they were all reunited the following day for what was called "normal post-flight reconditioning." 

 

Because this item made the news, we can assume that hospitalizing ISS astronauts right after landing is not normal.  And whatever the issues were, they were resolved fairly quickly.  But this incident brings up a larger question:  will humans ever be able to live "normal" lives in space for missions lasting years or even lifetimes?

 

A study published in Nature Communications last June shows that astronauts' kidneys may be a weak link in the plans to send humans on long space flights or residences in space.  It has been known for some time that astronauts who spend weeks or months in space are especially prone to develop kidney stones.  Anyone who has experienced the agonizing pain of this condition realizes that it's one of the last medical problems you want to encounter in a place where going down the street to the hospital is just not an option.  If the stone is large enough, anuresis (inability to pee) can develop, leading to a fatal case of uremic poisoning.

 

If I had to guess (and bloggers exercise that privilege all the time), I would say that the brief hospital stays may have been kidney-related, although it could also have been balance issues or other effects of long-term residence in space.  In space, kidney stones have no preferred location to drift to, but once you are standing upright on the ground, they will tend to head toward the exit, so to speak, which is just where you don't want them to go.  A well-equipped hospital can use lithotripsy (non-invasive technology to break up kidney stones) or endoscopic methods to clear the obstruction.  The procedure is uncomfortable but usually has a good outcome.  However, I doubt that the ISS is equipped for such procedures.

 

Even if kidney stones can be prevented, the Nature study showed that both microgravity and the galactic cosmic radiation that can't be practically shielded from in space can damage kidney function in other ways.  In the words of Dr. Keith Siew, one author of the study, "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."  Not an encouraging prospect.

 

The study showed that microscopic changes occur in the kidney tubules that do the filtering so necessary to the body's proper functioning.  It's not clear how much damage is due to radiation and how much to microgravity, but both are present in space and neither can be avoided. 

 

Anything worth doing involves challenges, and the problems of kidneys in space is only one of the manifold issues that astronauts face, up to and including sudden death in a collision with a meteorite.  And with proper planning, it's likely that this specific health issue will yield to either pharmaceutical treatment or some other workaround to enable astronauts to spend the several years in space needed to get to Mars, which seems to be the next goal of the humans-in-space race.

 

But it's possible that something like the old 2001:  A Space Odyssey suspended-animation process might come back if we can't find a way to keep a fully functioning human body going in the harsh environment of space. 

 

That doesn't matter to some people.  In 2013, an outfit called Mars One started selling one-way tickets to the Red Planet, and a surprising number of people signed up and paid the nominal reservation fee.  Apparently, there were enough folks here on Earth who saw getting away from it all as far as possible was a better option than what they were doing.  Mars One went bankrupt in 2019, so I suppose those one-way tickets may show up now and then on eBay, but otherwise won't do anybody any good. 

 

The point of that story is that some people would, in principle, take any risk in order to do a historic thing like land on Mars.  But these folks are clearly in the minority. 

 

There is a body of thought out there that our species' ultimate destiny is to migrate to other planets and basically keep doing what the Europeans did in the Age of Exploration:  find and exploit new uninhabited places to live.  And it's always a bad idea to underestimate the ingenuity of humankind.  Perhaps with some yet-uninvented technology and bio-modification of the human body, we could fix it so that millions of—somethings—could live on Mars.  I say "somethings" because if you modify the human form so that it can live on Mars, would these beings be capable of moving back to Earth?  Would they be permanent Martians rather that Earthlings?  It's hard to say.

 

The reader may be able to tell that I recently read a copy of Ray Bradbury's story collection The Illustrated Man.  Bradbury was not the least bit interested in the actual nuts and bolts of how to get to Mars.  I've even read one critic who said Bradbury "hated" technology, but I think that's an exaggeration.  What Bradbury used the trope of space travel for was to examine human relations—questions of racial discrimination, government, politics, and love.  And he probably did that better than any other science-fiction writer of his day.

 

He also realized that no matter how far humanity travels, we will carry the same old baggage of what the theologians call original sin with us.  And if people think that we could solve all our cultural and political problems simply by starting over on Mars or some yet-to-be-found planet, instead of spending billions on preventing kidney problems in future astronaut populations, they should read The Illustrated Man and realize that whatever problems space travel will fix, original sin isn't one of them.

 

Sources:  I referred to news items on the ISS astronauts' hospitalizations at https://apnews.com/article/nasa-astronauts-spacex-splashdown-f99e1724b4c131e68e0cf8c30274fc11, https://nypost.com/2024/11/02/us-news/nasa-spacex-must-maintain-focus-after-astronauts-hospitalized-safety-panel-says/, and https://nypost.com/2024/10/26/us-news/nasa-astronaut-remains-in-the-hospital-after-returning-from-an-extended-stay-in-space/.  A University College London article describing the Nature Communications study is at https://www.ucl.ac.uk/news/2024/jun/would-astronauts-kidneys-survive-roundtrip-mars, and the Nature article is at https://www.nature.com/articles/s41467-024-49212-1.  The news of Mars One's bankruptcy is at https://www.theverge.com/2019/2/11/18220153/mars-one-bankruptcy-bas-lansdorp-human-settlement. 

Thank God for Gravity: Scott Kelly's Endurance and the Future of Space Travel

Scott Kelly is a NASA astronaut, veteran of a year's stay on the International Space Station (ISS), and now a published author of a popular memoir called Endurance.  He is also the twin brother of fellow astronaut Mark Kelly, who is married to former Rep. Gabrielle Giffords, who survived an assassination attempt in 2011.  At the time Giffords was shot, her brother-in-law was in orbit during an earlier ISS stay.

Needless to say, Kelly has led an eventful life, and his memoir is rather unusual in that he doesn't shy away from matters that reflect badly on either him or aspects of the space program.  He is honest about many of his shortcomings, including his first marriage that ended in divorce.  And when in the course of narrating in detail his experiences in space, he is inconvenienced by a NASA policy or action, he lets you know about it.  The part of the book that describes day-to-day life on the ISS has got to be one of the most detailed and vivid descriptions of space flight in print.  And that's the problem.  If he wrote this book to encourage people to think about mass migration to space, it may have backfired.

To a landlubber like me, Kelly's trials and risks he undergoes to be in space are appalling.  Take what sounds like a simple thing:  a space walk.  First off, it takes about five hours to get ready, involving hundreds of separate checklisted steps, many of which if neglected or done in the wrong order could result in your untimely and painful demise. 

Then there is the zero-G environment.  I never really appreciated gravity until I read Kelly's book.  On earth, you put down a pen, or a wrench, or a screw, and it stays there.  Not in space.  Every single last thing you might possibly need has to be either tied down, kept in a bag, stuck to a piece of Velcro (TM), or otherwise secured, or else on the space walk you will inadvertently contribute to the already vast quantity of space junk orbiting Earth, and lose whatever you needed in the bargain.  The most chilling aspect of his space walks is to learn that over the nearly two decades that at least some of the ISS has been up there, meteors or orbiting pieces of derelict satellites have punched holes and taken entire chunks out of handrails on the outside of the structure.  And it's just a matter of chance whether another one of those 17,000-MPH pieces of debris drills a hole through you while you're outside. 

Kelly, along with anyone else who endures the rigors of years of training and competition to go into space, deserves accolades for his monumental achievements.  But at the same time, I can't help but wonder whether the up-close view of what life in space is really like lends more weight to the argument that, like many people say of New York, it's a nice place to visit but I wouldn't want to live there. 

The question really boils down to this:  is space, and whatever lies beyond in terms of potentially habitable planets, really more like America in 1620, or Antarctica in 1920?  Here's what I mean.

Right now, corporations are being organized to go into space exploration commercially, and large groups of visionaries are planning to spread humanity in some form to other planets.  From what I can tell, these folks believe that space and regions beyond it will eventually harbor lots of people, like the New World (North and South America) does now.  Some even seem to think that we have damaged our planet here beyond repair with global warming and pollution, and we better start making our plans for an exit strategy when Earth becomes uninhabitable.  Either way, these folks (who Kelly, incidentally, does not explicitly identify himself with) have an attitude toward space that says it is our manifest destiny to go there and occupy it with all the trappings of civilization:  cities, nations, the whole bit.  They would say that space now is like America was to Europe in 1620:  a new world beckoning us to explore and settle it.

If Kelly's spare-time reading had been about Columbus or Vasco da Gama, I might agree that he is of that party.  But what book did he take with him on the ISS?  Endurance:  Shackleton's Incredible Voyage, the story of Antarctic explorer Ernest Shackleton's ill-fated 1914 expedition to cross the Antarctic.  Their ship got stuck in ice and Shackleton and his men ended up floating away on chunks of sea ice and lifeboats.  In his choice of reading matter, I think Kelly has inadvertently answered the question of what space exploration is most similar to in the history of humanity so far.  And it doesn't bode well for any large-scale plans that involve moving lots of ordinary people into space.

There have been manned outposts in the extreme Arctic and Antarctic regions for about a century now, and the population of Antarctica still hovers in the hundreds at most.  The fact is that the environment there is so hostile to human life that living there is extremely expensive, inconvenient, and worth while only if a strong scientific or cultural motive justifies it. 

I think space is the same way.  It's hard to imagine how we could make space travel so safe, convenient, and comfortable that you could get lots of people (I'm talking thousands at least) to attempt it.  And by definition, you have to travel through space to get to anywhere besides Earth. 

So I salute Kelly and his compatriots for the incredible achievements they have made in simply keeping the ISS running and keeping alive up there, no small part of which is due to Kelly's accumulated expertise in repeatedly fixing what has to be the world's most expensive toilet.  But by the same token, I think space travel will remain a hugely expensive and highly specialized endeavor for a narrowly chosen few, for the foreseeable future—and maybe beyond that, too.

Sources:  I thank my wife for giving me Scott Kelly's Endurance:  A Year In Space, A Lifetime of Discovery (Knopf, 2017) for Christmas.

Radiation: The Unsolved Problem of Space Travel

These appear to be great times for future space travelers.  Commercial rocket outfits such as SpaceX are thriving, the Dutch organization Mars One is still refining their pool of potential Martian astronauts for a flight presently scheduled for 2032, and National Geographic's "Mars" docu-drama TV series has intermingled interviews with space experts and a dramatic portrayal of what an actual flight to Mars might be like, complete with death-defying crises. 

Then along comes Charles L. Limoli, a radiation biologist at UC Irvine, with his mouse brains shot full of holes, as he describes in an article published in the February 2017 issue of Scientific American.  They're not holes you can see with the naked eye—just tracks of ionization damage caused by nuclear particles intended to simulate the damage caused by cosmic rays and solar particle radiation that a typical years-long round trip to Mars would involve.  The bad news Limoli has is that when you take smart mice and shoot their brains with that much radiation, it damages certain fragile parts of the nerve cells:  the dendritic spines.  And they don't grow back.  So even high-IQ mice who get zapped in a NASA particle accelerator designed to simulate the type of radiation that astronauts will be exposed to, end up with what amounts to a mouse form of Alzheimer's.  The performance of these mice in certain mouse intelligence tests (don't ask me how they figured out how to do that) fell to only 10% of what it was before the zapping.  And the damage seems to be permanent, at least in mice.

So what, you say?  We'll just shield the space capsule.  Think again.

The more energetic a particle is—the faster it's going and the heavier it is—the harder it is to shield against.  Turns out that galactic cosmic rays, which are one of the two main kinds of radiation astronauts on deep-space missions will encounter, are the highest-energy particles known, with many of them having more energy than the most powerful earth-bound particle accelerators can produce.  The only practical radiation shielding presently used involves putting a lot of heavy stuff—concrete, steel, lead—between you and the radiation.  On earth, this isn't such a problem if you happen to have a disused salt mine handy—you just go underground.  But weight is the enemy of space travel, and a rocket that was shielded well enough to reduce cosmic-ray fluxes to something comparable to what we encounter on earth (shielded as it is by its magnetic field and atmosphere) would be prohibitively heavy.  We are talking shield thicknesses of many feet, all around the living areas of the vehicle. 

So at present, all these nice dreams of people spending years in deep space are still only that—dreams.  Based on the work of Limoli and others, sending astronauts on an unshielded rocket to spend a year or more in deep space would likely turn their brains into Swiss cheese, radiation-wise, with dire consequences that would affect everyone on board.  I don't know about you, but I can't think of a more depressing end to a space flight than to have everybody turn into candidates for assisted living in a matter of months.  And that's just if we try to get to Mars.  If the astronauts somehow manage to get there without losing their minds, the first thing they'd have to do would be to dig a deep burrow to shield themselves, or apply whatever unknown shielding technology they used on the trip to the newly established colony as well.

Space optimists look at this problem as just another speed bump on the road to Mars.  There may be medical ways of alleviating some of the damage that radiation causes to neurons.  But any such treatment is far in the future, and prospective space travelers need it now.  There is even less likelihood of finding a lightweight way of shielding against high-energy cosmic rays.  The physics of the problem has been well understood for decades.  In principle, you could use magnetic fields to create a shield, but the field intensity to deflect such particles is absurdly high—even the superconducting magnets in  today's MRI machines, which have to be carefully isolated from any ferrous object, probably wouldn't do the job.  And if you don't do something, you're condemning your space travelers to virtually certain mental decline.  Of course, some may think that this is just a risk we have to take.

Having watched the entire National Geographic "Mars" series over the Christmas holidays, I noted a disturbing tendency on the part of some enthusiasts for what I would term secular millennialism.  The religious millennialists called the Millerites were followers of William Miller, who convinced both himself and many others that he had figured out when the second coming of Christ would occur:  Oct. 22, 1844, about ten years ahead of when he was writing.  In the years leading up to 1844 he accumulated a large following who sold their farms, businesses, and houses and gathered in small groups, waiting for the big day.  In what became known as the Great Disappointment, nothing unusual happened, either then or later.

Secular millennial movements such as classical Marxism exact arduous and even painful sacrifices today for a promised millennial paradise tomorrow—and somehow, tomorrow never comes.  Some present-day promoters of deep-space travel have convinced themselves that the future of the human race lies not on Earth, but on Mars or other places where we'll be able to start over again and do it right.  If you really believe this, it's going to affect your attitude toward life on Earth.  After all, if we're just going to move soon, why paint the walls? 

It's not clear at this point whether radiation will pose a "deal-breaker" problem to deep-space travel.  I suppose if we get clever enough about orbital assembly stations, we could eventually manage to build a rocket that could carry enough conventional shielding to protect astronauts on their way to Mars.  But that does not seem to be in the current plans of many space enterprises. 

If somebody started calling for volunteers, or even offered lots of money, for people to jump off a thousand-foot cliff without parachutes "just for the experience," I hope we would find a way to shut them down.  That hasn't happened so far with Mars One, the Dutch outfit that is currently selecting people to go on a one-way trip to Mars.  But if by the time astronauts gets to Mars, their brains are so fried that they don't know where they are, it would be a shame for everybody—especially the astronauts and those who put them knowingly into a situation that was going to end badly. 

Maybe we'll figure this one out, but in the meantime, any time I see someone promoting manned deep-space flight, I'll be wondering what they plan to do about radiation.  And so far, I don't see anyone taking it seriously enough.

Sources:  Charles L. Limoli's article "Deep-Space Deal Breaker" is on pp. 54-59 of the Feb. 2017 edition of Scientific American.