The end of the Space Shuttle program has brought the question of man's future in space to the forefront. What are NASA's astronauts going to do between now and whatever comes next, go to Russia and hitch a ride to the ISS on a Soyuz? The question of men in space takes on a deeper significance when the future of men in space is measured in decades and generations rather than individual missions. In the coming millennia, will there be men in space? And if so, will they really be men at all?
There are five more or less commonly agreed upon reasons to pursue space exploration: scientific discovery, commercial technological applications such as GPS, national security, geopolitical prestige, and the survival of the human race. This latter rationale includes lofty goals like the colonization of Mars and the establishment of human outposts throughout the solar system. It is also the only real reason that demands the direct participation of men instead of machines.
Unfortunately, humans are lousy space travelers. Kurt Vonnegut put it best. In his novel Hocus Pocus, recurring character science fiction writer Kilgour Trout makes the point that humans are too bulky, complicated, and needy to survive any kind of prolonged journey into space."How could all that meat, needing so much food and water and oxygen, and with bowel movements so enormous, expect to survive a trip of any distance whatsoever through the limitless void of outer space? It was a miracle that such ravenous and cumbersome giants could make a roundtrip for a 6-pack to the nearest grocery store."
There are arguments that say we can get past the limitations of our humanity by evolving. As we migrate to new worlds, we will eventually adapt to become, say, a Martian strain of humans. Some proponents of Martian colonization, Robert Zubrin taking center stage among them, are confident that in a matter of three or four generations humans will adapt to the Martian environment. The first settlers' grandchildren could develop thicker skin to protect them from the low atmospheric pressure on Mars (it's about 1% that of Earth). They won't need cumbersome space suits with full helmets, just heavy suits to add minor pressure and a gas mask.
Let's say for a second that this did happen, that within three generations there was a strain of Martian-humans living fairly comfortably on Mars. But those Martian descendants won't really be humans. They might be to us what we are to the first fish with legs that ventured on to land—a distant relative with telltale common characteristics.
I am inclined to take the sceptics' view that it is unlikely humans will adapt to Mars within a century. It took us a lot longer than 100 years to become accustomed to out current environment. Not to mention hoping for adaptation to another environment isn't really a sure enough bet on which to stake the future of mankind.
So maybe we aren't meant to go on to colonize the cosmos. At least, not in our present forms.
We could create a race of cyborg humans. The term 'cyborg' was coined in the 1960s by Manfred D. Clynes and Nathan S. Kline to describe the modification of man to meet the demands and standards of a new environment. Strictly speaking, creating a strain of Mars—or cosmos-ready humans isn't all that far-fetched. Just stick them in a space-suit. That is a technology that would modify humans to meet the demands of a new environment, kind of like how we on Earth put on sunglasses when it's too sunny for our eyes. In fact, most of us are cyborgs. If you wear glasses, have metal plates and screws holding broken bones together, or use a prosthesis at all, you've been modified to meet the demands of your environment.
Unlike the Martian-humans that eventually adapt to the Martian environment, however, superficial (literally) adaptive technologies don't make it any easier for men to live in a new environment. But what if we took the modification of men into cyborgs further. Here's where the future of men in space gets wacky.
We could modify men on Earth to prepare them for life on Mars. We could start selectively breeding men right now to have favorable generic mutations such as a need for less oxygen or higher starting bone density, increasing life spans such that a single crew could make significant headway in setting up a base on Mars. Once on Mars, our custom-made astronaut would adapt to his new life much more easily than the run-of-the-mill human.
We could go a step further and implant technology directly into the human body to make a man fit for life on Mars. Iron lungs and steel plates under his skin would make him more resilient, but as Lamarck taught us, those modifications wouldn't be passed on to his progeny.
Some of the most outspoken proponents of manned space exploration are in favor of creating a race of post-biological human: a being that would take the essence of a man—his rational faculties, intelligence, and personality—and put it in the durable outer casing of a machine. This would make colonizing the cosmos significantly easier; a power source is a simpler and more space-efficient way to keep 'astronauts' alive than cumbersome things like food, water, and air.
Building a race of robotic humans would be to 'play God' as they say. We would have to create a self-sustaining machine capable of reproduction with sophisticated artificial intelligence. This race would be human progeny in the loosest sense of the word. They may be to us what we are to the primordial soup that started life on Earth; we came from it, but that's where the similarities end. It could, however, be the most promising way to ensure the survival of the species, at least in essence.
But artificial intelligence can't take the place of a man's mind, and a robot's physicality is far from human being's. Robots are getting smarter and more sophisticated, but there are things that robots can't learn and faculties they can't develop.
Apollo 17 astronaut and moonwalker Harrison "Jack" Schmitt is an outspoken supporter of continued manned spaceflight for three reasons: eyes, hands, and mind.
Human eyes can take in more data and process it faster than any camera attached to a circuit board in a robot. Humans dexterity has as of yet not been reproduced in a robot. We don't think about the pressure needed to pick up an object, but this simple act needs to be calibrated in a robot so it doesn't drop or crush the object of its study. The human mind, perhaps most unique of all, has reason and experience at its disposal. A man can make a quick decision and react instantly, say, to an approaching dust storm on Mars. A robot would have to 'see' it, figure out what it is, decide what to do, then act.
Those who agree with Schmitt, and I would include myself among them, typically see Mars as a scientific curiosity rather than a new Earth. A geologist on Mars could gain more from a brief sojourn on its surface than he could gain from all the data that has been sent back to Earth. If we can devise ways to keep astronauts safe and healthy on a round-trip mission to Mars, it's worth going for the scientific return.
Not to mention, a quick trip to Mars wouldn't require implantation of iron lungs and body armor.
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