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The Human Body May Not Be Cut Out For Space
Hugh Pickens DOT Com writes "The human body did not evolve to live in space, and the longest any human has been off Earth is 437 days. Some problems, like the brittling of bone, may have been overcome already. Others have been identified — for example, astronauts have trouble eating and sleeping enough — and NASA is working to understand and solve them. But Kenneth Chang reports in the NY Times that there are some health problems that still elude doctors more than 50 years after the first spaceflight. The biggest hurdle remains radiation. Without the protective cocoon of Earth's magnetic field and atmosphere, astronauts receive substantially higher doses of radiation, heightening the chances that they will die of cancer. Another problem identified just five years ago is that the eyeballs of at least some astronauts became somewhat squashed. 'It is now a recognized occupational hazard of spaceflight,' says Dr. Barratt. 'We uncovered something that has been right under our noses forever.' NASA officials often talk about the 'unknown unknowns,' the unforeseen problems that catch them by surprise. The eye issue caught them by surprise, and they are happy it did not happen in the middle of a mission to Mars. Another problem is the lack of gravity jumbles the body's neurovestibular system (PDF) that tells people which way is up. When returning to the pull of gravity, astronauts can become dizzy, something that Mark Kelly took note of as he piloted the space shuttle to a landing. 'If you tilt your head a little left or right, it feels like you're going end over end.' Beyond the body, there is also the mind. The first six months of Scott Kelly's one-year mission are expected to be no different from his first trip to the space station. Dr. Gary E. Beven, a NASA psychiatrist, says he is interested in whether anything changes in the next six months. 'We're going to be looking for any significant changes in mood, in sleep, in irritability, in cognition.' In a Russian experiment in 2010 and 2011, six men agreed to be sealed up in a mock spaceship simulating a 17-month Mars mission. Four of the six developed disorders, and the crew became less active as the experiment progressed. 'I think that's just an example of what could potentially happen during a Mars mission, but with much greater consequence,' says Dr. Beven. 'Those subtle changes in group cohesion could cause major problems.'"
The solution may be much simpler than thought, Nasa only recruits High performing Individuals these people have a quite well documented need to perform and to be "busy" mentally or physically what they might need is couch potatoes or Mall security guards.
That is why we need to adapt the environment to our needs.
A big spinning wheel shaped vehicle should suffice, albeit full of technical challenges.
Millions of years of evolution in an environment with gravity has really screwed up our plans for galactic supremacy.
If got had meant us to be in space he would have made us with skin that replaces cells with polarized silicone and given us acid for blood.
You are just looking for a viable excuse for shooting your mother in law to the moon.
Another problem identified just five years ago is that the eyeballs of at least some astronauts became somewhat squashed. ... 'We uncovered something that has been right under our noses forever.'
I'm not a doctor, but if your eyeballs have always been under your nose then I suspect you have a pre-existing condition. Don't blame space.
To be fair, in zero gravity, it's easy to get confused about 'under' and 'over'.
In a survey of 100 programmers, 111111 thought that duck-typing was a good idea.
That is a good idea in theory, but artificial gravity by rotation has a rather big problem involved: We're not 1 inch tall. Gravity by rotation is dependent on velocity. And depending on how "big" that wheel is, that velocity may be considerably different at the floor and 6 feet up.
In other words, if that wheel is too small and you spin it too fast (to get to that 1g you want), you'd be nauseated to the extreme.
I don't have the exact numbers in my head right now, but I do distinctly remember that the required size was somewhere in the vicinity of "friggin' huge" to avoid such a fate.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
"The human body did not evolve to live on ships, and the longest any human has been off Land is 437 days. Some problems, like scurvy, may have been overcome already. Others have been identified -- for example, sailors have trouble eating and sleeping enough -- and people are working to understand and solve them. But Kenneth Chang reports in the NY Times that there are some health problems that still elude doctors more than 5000 years after the first sea voyage. The biggest hurdle remains sea water. Without the protective cocoon of the ships hull and atmosphere, sailors receive substantially lower doses of oxygen, heightening the chances that they will die of suffocation. Another problem identified just five years ago is that the eyeballs of at least some sailors became somewhat squashed when hit by a boom. 'It is now a recognized occupational hazard of sailing,' says Dr. Barratt. 'We uncovered something that has been right under our noses forever.' Officials often talk about the 'unknown unknowns,' the unforeseen problems that catch them by surprise. The eye issue caught them by surprise, and they are happy it did not happen in the middle of a mission to Madagascar. Another problem is the lack of stability jumbles the body's neurovestibular system (PDF) that tells people which way is up. When returning to land, sailors can become dizzy, something that Mark Kelly took note of as he piloted the sailboat to a landing. 'If you tilt your head a little left or right, it feels like you're going end over end.' Beyond the body, there is also the mind. The first six months of Scott Kelly's one-year mission are expected to be no different from his first trip to the open sea. Dr. Gary E. Beven, a NASA psychiatrist, says he is interested in whether anything changes in the next six months. 'We're going to be looking for any significant changes in mood, in sleep, in irritability, in cognition.' In a Russian experiment in 2010 and 2011, six men agreed to be sealed up in a mock submarine simulating a 17-month mission. Four of the six developed disorders, and the crew became less active as the experiment progressed. 'I think that's just an example of what could potentially happen during a submarine mission, but with much greater consequence,' says Dr. Beven. 'Those subtle changes in group cohesion could cause major problems.'"
I have no trouble believing the human eye does not do well in zero gravity. Case in point, I have a bookstand that holds a book upside down, to read lying down in bed. If I read for an hour in that position, my vision becomes all blurred, something that doesn't happen when I read with my head upright or tilted backward at a slight angle.
I'm pretty sure proper vision depends on gravity pulling the eyeball the direction the eyeball is used to to maintain its shape, i.e. down.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Turning one's head rapidly in such an environment causes a "tilt" to be sensed as one's inner ears move at different rotational rates. Centrifuge studies show that people get motion-sick in habitats with a rotational radius of less than 100 metres, or with a rotation rate above 3 rotations per minute. However, the same studies and statistical inference indicate that almost all people should be able to live comfortably in habitats with a rotational radius larger than 500 meters and below 1 RPM.
That would mean a rather massive structure. So, an alternative design that would use less material is two stations tethered together and rotating around a common center. Or a station and a counterweight. Still, this requires a strong tether, which also means additional mass.
This approach is suggested, for example, in this Mars Society article: The Use of SpaceX Hardware to Accomplish Near-Term Human Mars Mission.
For radiation shielding, they suggest to use the "consumables", which probably means fuel, raw materials, equipment and water.
Long term residence at zero G may be a problem, but we may not need full gravity (9.8m/s2) to be healthy, especially if you don't have to return to earth.
Lets face it, the first planets we colonise have a reduced gravity ( Mars 3.7m/s2 and Luna only 1.6m/s2)
Er... they do.
Notice that most of the problems are associated with the lack of gravity (not generally a problem on a submarine), not a confined environment.
You don't get bone loss as a submariner.
You don't get modified eyeball shapes as a submariner.
You don't get extreme dizziness once you set foot on dry land as a submariner (an experienced one at least)
Sleep loss? Maybe. But saying you can't sleep on a tin box inside an ocean of resonant water where you have to keep absolutely silent is a bit different to a tin box travelling at thousand of miles per hour in the vacuum of space.
In fact, if anything, it's completely the OPPOSITE problem.
Hence why people at NASA don't see these problems coming.
I'm just thankful it's not something more serious and obviously debilitating (if you're going to spend your life in space, bone weakness isn't going to be much of an issue - it's only the return to Earth that's the problem) or the whole "let's life in space" program might have been dead before it began.
The required radius is about 500m, as I mentioned in my other post here. The smaller, cheaper alternative is a tethered design.
PersonFrom1420 submitted via church door nail, "The human body was not designed by God Almighty to live on the ocean in seafaring ships, and the longest any human has traveled has been close to coastlines. Without the protective cocoon of the coastal fish and shore leave, nautical travelers are subjected to Gout, Scurvy, and a malaise of the spirit that shall certainly result in dire consequence for any vessel attempting to find a new world to explore. In a Royal experiment, debtor's prisons are filled with scum of the streets, sealed away, and their outcome is surely the same as a nautical traveler who looks forward to a new life and possible riches from fruitful exploration. Also, if even one ship has a mutiny, NASA (the Nautical Authority of the Spanish Armada) should instantly force all manned sea faring traffic to halt for over a year, as various Royal Agencies, none of whom understand how to tie a knot, let alone sail a ship, confer over the loss, and consider halting this foolishness to focus on more incense swinging for the plague and merkin production at home. Certainly there is no profit to be gained in these new lands that are worth losing entire ships of human beings over, and there can be no future lands there that will ever be suitable for our children's children. May this missive find you in good health, Signed P.F.1420"
"$30 for the One True Ring. $10 each additional ring!" -- JRR "Bob" Tolkien
Agreed, 100%, the human body is not cut out for space. Certainly, like all life on earth, we require oxygen, we evolved with gravity, radiation is toxic, and so forth. Our bladders, for instance, tell us that we need to urinate based on a sense that depends on gravity holding urine down at the bottom; without gravity, if we wait until we feel the need to urinate, we need to be catheterised.
BUT... the human body isn't cut out for a lot of things THAT HUMANS DO ON A DAILY BASIS. We're not cut out for flight; we're not cut out for deep water diving; we're not cut out for rapid movement on ground. Yet, with technology, we do all of the above. Absolutely, space flight requires far more in the way of adaptations to protect our (very) frail bodies than air travel, SCUBA, or cars. But human history, broadly simplified, is the story of us using our brains to overcome our manifest physical handicaps.
-Z
According to someone else's comment just above, the absolute minimum size required for most humans to be comfortable is 100m radius and rotation rate of 3 rpm. Going up to 500m radius and 1rpm would make the habitat comfortable for almost everyone.
Sounds like a lot, but we build much larger structures that this all the time here on Earth which are capable of withstanding the forces of storms at sea, battering waves, etc.; they're called "ships". The biggest ones are about 400m long. Something built for space doesn't need to be remotely as rugged as an aircraft carrier, since there's no gravity or other forces to deal with besides those caused by rotation and propulsion, so it really shouldn't be that hard to build something that size if we put our minds to it and actually dedicated serious resources to the task instead of sitting around and debating Creationism.
Earth is already a spaceship. The problem is, we have no control over where it's going.
But we found the climate controls! We just argue over how hot to set them.
The spinning is for the astronauts, right? Set up a spinning pod section that was designed for astronauts only.
An astronaut climbs in and presses a button and the system compensates, much like fuel redistribution on a modern plane. Once the system is balanced, it spins up. Astronaut sleeps under gravity. Wakes up. Gets out. Time for next astronaut to sleep. Repeat.
I come here for the love
In his novel Time is the Simplest Thing, he wrote [paraphrasing] the human body was not cut out for space travel, a man dies to easily from radiation when passing through the Van Allen belts. This was written in 1961 -- just after the Van Allen belts were discovered and just before the first manned spaceflight.
Incorrect. It is far more efficient to adapt your bodies to survive the environment.
Then why do people build houses? Why were things like the furnace and the air conditioner invented? Heck, why was clothing invented?
Most of Earth's surface is an unsustainable environment for humans, for at least part of the year. We only live on this planet because we have developed many ways of altering the environment.
The "437 days in space" is a lie - humans cannot survive at all in space. The 437 days was in a capsule, a local modification of the true environment of outer space.
There once was a babe born in space
The first of the whole human race
But the kid's DNA
Looked like bad macrame
Cos nobody shielded that place