Humans Not Meant for Space

[Arwena]

Interference suggested a new thread on this question. It came from a thought on Monday's 40th anniversary of the moon landing. Many thought then that a new human era had begun, but we haven't made any progress. In fact, no human being has traveled beyond low earth orbit since 1972. Some have suggested that human beings simply are not "equipped" for travel beyond their home planet. They after all have to take their (rather delicate) home environment with them. Without the protection of a thick atmosphere, they'd be subject to lethal radiation. Psychologically, they would be separated from a social environment and would eventually go mad. (of course, we occasionally go mad here.) I would hope that this is not true, and that someday, further in the future than we'd hope, we will boldly go where no one has gone before. Maybe part of the problem is that space travel presents more difficulties than we imagined, that there are no destinations in our immediate area of space (the solar system) that are desirable or would justify the huge expense involved. Interstellar travel presents challenges that we have yet no idea of how to overcome. At any rate, Whenever it is said (by those anonymous people who say such things) that something is impossible, I tend to be skeptical of"impossibility"

 

[Interference]

Personally, my view as things stand is that we're going to need to leave the planet quite soon. In favour of this proposition are the destruction of human-life-supporting conditions and the rise in population.

Against is our human frailty, in all its guises.

Whether all of us (or the extant population at the time) or only an elite few will be involved is worthy of some attention, and Asimov has done this, I think, quite well. So a partial answer to this is certainly "some humans are meant for space travel, others have to tend the farm".

But perhaps even more excitingly is the question of what form space travel will have to take in order for us to embark on it. Star Gates may be best option, given distances and all the dangers inherent therein. But how likely are Star Gates? Will it necessitate planting a receiver on one planet at a time? Probably, but then advance terraforming would also be a necessity, surely, if we are to colonise that planet eventually.

Suddenly the question is getting to be quite vast.

Ideally, we should all be allowed to visit other worlds, not just a few elite militarists. How achievable is that? If we weren't dependent on the mechanics of space flight, we might all stand a better chance, but now we're getting into the territory of psychic projection and Remote Viewing, which is (probably) safer and allows the traveller to explore worlds which are completely hostile to physical human life. Now, perhaps, the question becomes "can we equip ourselves as individuals for space exploration".

Exploration is in our natures, I think, though quite how this anthropological defect sits so well alongside our nesting instincts I'm not entirely sure, so one day we will get there, I'm sure. It will be interesting for those of us still around at the time what method is employed in the end to make it comfortable and convenient for us, like the jet brought opposite sides of the world together.

 

[chrispenycate]

Humans are not "made" for polar exploration or high mountains, either. Or living in close proximity in cities. We have a tradition of modifying the environment to suit us, rather than adapting to it. This has generally involved technology, our speciality as a species.

Certainly, this has caused problems in the past, and doubtless will do so in the future, but it renders irrelevant what we evolved for, specifically.

 

[Pyan]

Humans aren't meant to live in Los Angeles, or any other major city, if it comes to that - they'd die of thirst if the water system packed up...

As Chris says, the thing about our species is that, uniquely, it adapts the eviroment it lives in, and not vice versa. Space will be no exception.

 

[Nik]

Well, if you consider our kin can endure life as hunter-gatherers in the Outback, on the tundra, in rain-forests crawling with nasties, in cities crawling with nasties etc etc.

Pole to pole, apex to trench, albeit with lots of tech, plus that 10% death-zone on Everest...

Ocean crossing was hard, what with storms and scurvy.

Um, IIRC, one factor that frightened US politicians about 'extended Apollo' was the solar flare / CME that missed toasting a crew by a few days. #13 got lucky. A crew puking with radiation sickness might not have endured.

As for accidents-- Apollo 1, the pad-fire, set the project back a year, but probably saved it. The Shuttle's lessons don't seem to have been learned by NASA beyond 'run away', which is why the 'Plan B' team may get the franchise.

FWIW, all the expendable launch folk will be looking over their shoulders at Alan Bond's Sabre engined Skylon. That would reduce NASA to 'heavy lift' supplier until a four-engined S2 comes along. After that, NASA are infrastructure, museum and theme-park...

IIRC, opening the solar system needs nuclear power. Treaty prohibitions on fission reactors probably mean we're waiting on fusion. At the rate ITER etc are going, the polywell approach may arrive sooner and safer...

But, where a fission reactor relies on lots of dumb mass for shielding, a fusion reactor uses magnetic and electrical fields. IIRC, there's enough circulating power in either ITER or polywell that 'bending' the charged solar wind flux comes easy. That still leaves neutrals and photons, but a fusion-powered rocket has a much more generous mass budget...

As regards bone loss etc, there have been some developments that *may* lead to pharmaceutical prevention.

Sure, we're not 'meant' for space. We'll go anyway. Besides, we gotta be off-world when the next Toba blows...

 

[Xelebes]

To prevent bone loss, you only need sufficiently wide and rotating craft to simulate Earth's gravity.

 

[Nik]

Wow ! I wonder if Circus-Circus will grab the Lunar & Martian franchises !!

 

[Parson]

Well, if you consider our kin can endure life as hunter-gatherers in the Outback, on the tundra, in rain-forests crawling with nasties, in cities crawling with nasties etc etc.

Pole to pole, apex to trench, albeit with lots of tech, plus that 10% death-zone on Everest...

Ocean crossing was hard, what with storms and scurvy.

Um, IIRC, one factor that frightened US politicians about 'extended Apollo' was the solar flare / CME that missed toasting a crew by a few days. #13 got lucky. A crew puking with radiation sickness might not have endured.

As for accidents-- Apollo 1, the pad-fire, set the project back a year, but probably saved it. The Shuttle's lessons don't seem to have been learned by NASA beyond 'run away', which is why the 'Plan B' team may get the franchise.

FWIW, all the expendable launch folk will be looking over their shoulders at Alan Bond's Sabre engined Skylon. That would reduce NASA to 'heavy lift' supplier until a four-engined S2 comes along. After that, NASA are infrastructure, museum and theme-park...

IIRC, opening the solar system needs nuclear power. Treaty prohibitions on fission reactors probably mean we're waiting on fusion. At the rate ITER etc are going, the polywell approach may arrive sooner and safer...

But, where a fission reactor relies on lots of dumb mass for shielding, a fusion reactor uses magnetic and electrical fields. IIRC, there's enough circulating power in either ITER or polywell that 'bending' the charged solar wind flux comes easy. That still leaves neutrals and photons, but a fusion-powered rocket has a much more generous mass budget...

As regards bone loss etc, there have been some developments that *may* lead to pharmaceutical prevention.

Sure, we're not 'meant' for space. We'll go anyway. Besides, we gotta be off-world when the next Toba blows...

Nik,

A lot of good thought here, and for me a lot of gobbly gook. What pray tell does IIRC mean? and CME? and FWIW? and ITER? or Toba?

Am I showing my lack of technical science backgroud?

The real reason we have not pursued further space exploration in my opinion is that there does not seem to be anything tangible to gain, except insight that intrigues scientists but leaves the majority of the population wondering what the big fuss is about.

 

[Interference]

For what it's worth, I got FWIW, but I forgot what IIRC is, which is why I'm going here next ...

ITER, though, is probably International Thermonuclear Experimental Reactor, and of course it was the Certified Marketing Executive that missed toasting a crew by a few days, naturally

Toba is a musical brass instrument.

 

[Ursa major]

IIRC - If I Recall Correctly

CME - Coronal Mass Ejection (Coronal mass ejection - Wikipedia, the free encyclopedia)

FWIW - For What It's Worth

ITER - International Thermonuclear Experimental Reactor (ITER - Wikipedia, the free encyclopedia)

Toba - see Toba catastrophe theory - Wikipedia, the free encyclopedia




EDIT: I also use http://www.acronymfinder.com/, for what it's worth. (Sometimes there are pages and pages of possible expansions of an acronym, so you sometimes have to have a vague idea of what you're looking for.)

 

[skeptical]

For acronyms, just put the acronym into google and it will give you the answer really rapidly. I make good use of google. I cheat at crosswords....

As far as the question of "are humans OK for space?" - the answer is no and yes. No, we are not adapted to space, but, yes, we will overcome that problem as we have overcome heaps of others.

We will do this partly by building environments in space that suit us, such as advanced radiation shielding (magnetic fields?) and rotation for artificial gravity. And no. We will not use star gates. That is an SF concept, not one of science.

We will also use genetic modification to make us better equipped for space dwelling. There are organisms on Earth, for example, that have fantastic DNA repair mechanisms, that can survive massive doses of radiation. There is no theoretical reason why we cannot genetically engineer our own bodies to give us superior DNA repair, and allow us to survive the doses of cosmic radiation that space travel will entail. Of course, this is 100 years plus in the future.

With sufficient development in genetic engineering, I see no theoretical barrier to stop us creating humans that can even take a deep breath and stay in hard vacuum for 10 minutes. Similarly, it may prove easier to engineer people who can tolerate micro-gravity for long periods, rather than use artificial gravity from rotation.

In another 100 years, we may have a new sub-species of human able to survive the stresses of space travel far better than us 2009 inferior types.

I do not think that space travel is ever likely to provide a solution to over-population. However, I do not think such a solution is required. The United Nations demographers point out that population growth is slowing, and that the world will probably peak at around 9 billion in another few decades. ( www.un.org/popin ).

A simple calculation shows that advanced agricultural methods (hydroponics) can feed 9 billion while using only the amount of land that occupies the northernmost one quarter of Australia - so I think 9 billion is something our species can adapt to.

At the same time, I think our long term destiny lies in space. Even though IMHO (try this in google), only a tiny percentage of that 9 billion will ever leave the Earth's gravity well, those that do will, in the long run (thousands of years) be the parents of most of humankind in the even longer run (tens of thousands).

 

[Granfalloon]

Well, If you must know the answer - It's Money. Space travel is very expensive and doesn't seem to get as much funding as say, er... War on Iraq. It may be that until man (America?) stops wasting his money on other things, more money would be available for space exploration. The issue I have with it when you look at the big picture - our priorities are screwed up. We can't even feed the hungry people in the world, and we spend so much of our $ on military. \

 

[skeptical]

Granfalloon

You are correct. However, I still have hope for the future. War is not the same today as it was mid 20th Century and earlier, and I believe things are moving in the right direction. It is not widely publicised, but the number per million humans dying each year from war has dropped dramatically. Instead of massive destructive wars like WWII, we now have such things as terrorism and counter-terrorism, plus minor wars. Even the idiotic Iraq war is minor by standards of 60 years ago.

If humanity can learn to stop spending $$$ and lives on stupid wars, we might be able to invest in space. I think the real essential step is not moon or Mars colonies, but the building of the first space elevator, which will make the rest possible. However, that will cost $1 trillion plus.

This should happen within 100 years, and should herald the beginnings of the great expansion into space. If a space elevator is run way beyond the stationary orbit zone, and its carriages are carried out to its terminus and released, they will flick into space with great speed - giving them a tremendous start to a journey to the moon or the planets, and eventually, the stars.

 

[Urlik]

If a space elevator is run way beyond the stationary orbit zone, and its carriages are carried out to its terminus and released, they will flick into space with great speed - giving them a tremendous start to a journey to the moon or the planets, and eventually, the stars.

if it continues beyond the optimum geostionary orbit zone then it will put too much strain on the structure.

and releasing the carriages defeats the benefits of an elevator.
the upward bound carriages carry prefabricated parts to build huge colony ships in space and the downward bound carriages carry raw materials mined from the moon or asteroids. the mass travelling down is used to help lift the mass travelling up so that the cost of getting materials into orbit is far less than it is today (possibly even free if enough materials are mined and is in excess of the mass to be lifted to orbit).

if a ship is built in orbit it doesn't need a boost from the elevatoer either. it has already bypassed the costly stage of escaping from Earth's gravity.

 

[Parson]

Thanks for all the acronym help! I have now bookmarked acronymfinderand I may not have to ask such questions again.

I agree that true space utilization does not begin until after a "sky hook" is built. But I would still maintain that we are going to have to have a "good" reason to do so, or else the majority of the population will see it as taking food or more likely conveniences from them. In the more democratic world which may be shaping up this could be the death knell for any serious space utilization.

 

[skeptical]

Urlik

I may not have explained the point well enough. A space elevator must extent well beyond the geostationary orbit point. If not, the weight of the cable or ribbon below that point will fall due to Earth's gravity, dragging the whole lot back to Earth, disastrously. Most proposals I have seen have suggested a counter-weight, hanging off the cable or ribbon, well out past the geostationary point. This is subject to centrifugal action, holding the whole structure taut.

However, it has always been my own opinion that a counter-weight is not needed. The cable or ribbon itself can act as counter weight if it goes far enough out.

Also, simply building a space vehicle at the geostationary point has always seemed to me to be a waste. This is because it then has to accelerate, wasting reaction mass, to get to Mars, or the moon or whatever. On the other hand, if it is moved to the outer end of the cable, it will already have the velocity to leave Earth orbit, just by the velocity imparted by the cable. No reaction mass is required. If released from the end of the cable at the correct (computer calculated) moment, it will fly at great speed towards its destination.

Incidentally, for your information, the geostationary point is 36,000 kms out from Earth, and without a counterweight, the space elevator would need to be a little more than double that length. Say 75,000 kms long. A space vessel released from that point would have a tangential velocity of about 3 km per second - easily enough to achieve escape at that micro-gravity.

 

[Karn Maeshalanadae]

Humans not meant for space. I believe Chris has already made the argument-humans aren't naturally meant for anything we've done.

Space life? Possible. Uncomfortable for a while, but hey, we haven't been around for a million years by being horseshoe crabs, now have we?

I find it to be an interesting concept. More room in space, but....how do we get farming soil? Shipments at first, but that would take away from the Earth, other planets are too far-not to mention perhaps not made for Earthling plants-and I'm not entirely sure how fertile moon or asteroid soil would be.....

 

[Urlik]

skepical,
it makes no sense to build the ships on earth's surface and use the space elevator to launch them.
the ships would have to be small to be lifted by the cable compared to craft built in orbit from prefabricated parts.
the amount of energy required to leave orbit is minuscule in comparison to the amount needed to get from the surface up into orbit (just look at how much of the Apollo rocket was needed to get such a small payload into orbit compared to how much was needed to get from an Earth orbit to a Lunar orbit and back again)

the benefit of the elevator is that resources mined from asteroids and the moon going down the elevator to the Earth help lift prefabricated parts and fuel into orbit so getting there is almost free.
the minuscule amount of fuel needed to leave orbit is negligible (and hardly cost anything to get into orbit in the first place)

 

[skeptical]

Urlik
I did not say the ships would be built on the Earth's surface, though I suspect that a lot of prefabrication would occur there.

No, the place to build ships is at the geostationary point, where there is apparent zero gravity. However, the launching point would be at the end of the tether. It would be relatively easy to attach the completed ships to a magneto-levitation cart that rode the cable. The entire ship would then travel to the end of the cable for release. The acceleration to 3 km per second is thus achieved using electricity, not reaction mass.

In fact, if a sufficiently effective magnetic acceleration system could be designed, the vessel would leave the end of the cable at a lot more than 3 km per second. It might even be possible to accelerate a ship to sufficient speed to coast all the way to Mars, or even leave the sun's gravity well altogether, conserving its reaction mass for deceleration.

It would even be possible to part build and launch vessels, and have the various parts launched in such a way as to meet, and complete final joining into one big ship at a point en route to final destination.

Mars, at closest pass to the Earth, is about 60 million km away. At 3 km per second, it would take just under 2 years to cover this distance. So extra launching velocity from magnetic acceleration would be very desirable. My own feeling is that to accelerate from geostationary orbit (36,000 km out) to the end of the tether (75,000 km out) gives plenty of scope for massive velocity increase.

We need to remember that a space elevator will probably not happen for another 100 years. By then, magnetic levitation and magnetic acceleration technology should be massively advanced over what we have today. Humanity should also have cracked nuclear fusion, meaning unlimited cheap energy. With all that enhanced technology, acceleration to a velocity way more than 3 km per second should be achievable.

 

[chrispenycate]

Urlik

I may not have explained the point well enough. A space elevator must extent well beyond the geostationary orbit point. If not, the weight of the cable or ribbon below that point will fall due to Earth's gravity, dragging the whole lot back to Earth, disastrously. Most proposals I have seen have suggested a counter-weight, hanging off the cable or ribbon, well out past the geostationary point. This is subject to centrifugal action, holding the whole structure taut.

However, it has always been my own opinion that a counter-weight is not needed. The cable or ribbon itself can act as counter weight if it goes far enough out.

Also, simply building a space vehicle at the geostationary point has always seemed to me to be a waste. This is because it then has to accelerate, wasting reaction mass, to get to Mars, or the moon or whatever. On the other hand, if it is moved to the outer end of the cable, it will already have the velocity to leave Earth orbit, just by the velocity imparted by the cable. No reaction mass is required. If released from the end of the cable at the correct (computer calculated) moment, it will fly at great speed towards its destination.

Incidentally, for your information, the geostationary point is 36,000 kms out from Earth, and without a counterweight, the space elevator would need to be a little more than double that length. Say 75,000 kms long. A space vessel released from that point would have a tangential velocity of about 3 km per second - easily enough to achieve escape at that micro-gravity.

The centre of gravity of the system must be precisely in geostationary orbit. thus, there must be as much mass outside the geostationary stable point as hanging down ti Earth. If you put a big enough counterweight at the precise point, it tends to damp out minor variances in the tension like a capsule climbing the tower (although it would probably be a good idea to send a counterbalance capsule down), or a hurricane. If you have too much mass outside the counterweight, just as if you have too little, the structure winds itself round the equator like a thread round a bobbin, and several megatonnes of extremely energy-rich matter crash down the entire length of the tropics.

Certainly it would be possible to monitor the position of the tower at all times, and continuously correct for minor variations, but this would require near continuous expenditure of reaction mass, and make a ridiculously tempting target for some ambitious terrorist. A big lump of passive matter is less sophisticated, perhaps, but avoids a computer error being able to cause the biggest disaster in human history; even evacuating the tropics (fun) I'd expect a death toll in the hundreds of millions.