How Close Are We To Colonizing Space?
io9.com
io9.com
We are way bleeping far away from colonizing space...
The problem that low gravity significantly accelerates aging isn't often mentioned but it serves as a pretty decisive hindrance.
I mean, even a permanent settlement is a long way from colonization. We have permanent bases on Antarctica. We aren't planning to colonize any time soon.
That part of the Jetsons will have to wait...
Interesting. Sources?
http://weboflife.nasa.gov/currentResearch/currentResearchGen...
"The lack of gravity during space flight affects living things in a variety of ways. A number of these mimic common effects of aging."
Puts it very nicely. Perhaps the space scientists don't want scare people about going into space.
Also, more googling for you:
www.joanvernikos.com/uploads/space_and_aging.pdf
As the duration of space flight missions has increased, many other symptoms related in particular to being away from gravity have been observed. They include a kind of anemia due to reduced red cell mass, muscle atrophy and reduced strength of those muscles that keep the body upright, loss of calcium from bones, reduced bone density and strength, reduced calcium absorption from the gut, disturbed sleep and a depressed immune system. These are all normal body function adaptations that occur when away from gravity. Degradation of body functions no longer needed in space is the normal adaptation to living away from gravity.
-- Simulates the effects of aging...
OK, these are pretty bad, but they're not literally cancer. My space-age dreams live on.
With the things are going, you're more like to download yourself to a computer and then go into orbit than human society is to put biological human very far into space.
This should be testable on Earth with people kept in bed 23 h/day and mild exercise. (It is like quite a few coding people's lifestyle.)
Come to think of it, we already have colonies on the ocean floor, they're called oil rigs, and they're economically viable. I wouldn't want to live there, though.
If Fermi's Paradox comes from a limiting factor "removing" civilizations (a physics experiment, etc), it should need to destroy a whole solar system and not only a planet. Otherwise it would only remove the fraction of civilizations that didn't develop an Orion before that experiment.
IIRC, NASA killed Orion politically? They might have exterminated humanity -- for job security...
and orion would have been detonating them not-too-distant from earth when ramping up for interstellar voyages.
Can you imagine a streak of detonating nukes all the way to LEO?
Extreme, world changing (in more than one way) and mind blowing (also in more than one way!) technological marvels might not be your cup of tea?
Edit: I might add -- if you can't handle tea, stay with the boiled water...
>>Can you imagine a streak of detonating nukes all the way to LEO?
I can imagine it -- all the way to Saturn's moons, by way of the asteroid belt. What a beautiful dream.
But certainly, a careful analysis of the failure modes might be considered prudent. An infrastructure outside the atmosphere would easily arguably be worth at least a small increase in cancer risk.
(Today is a different matter of course, since it would be detrimental to lots of very expensive satellites' health.)
What I don't like is the huge EMP destroying electronics across half a planet and the fallout making three-eyed fish.
Orion is great, but we would have to find cleaner propellants if we really want to build a lot of them ;-)
It's also unclear how many we could propel with the amount of fissiles we have on Earth.
Was that a joke? Can you give a reference which discusses how many thousands ton of nukes that are limiting...?
(Hint, not that much uranium is needed for those bombs. Also, from what I've read -- if the Uranium prices go up a bit, there will be much more mined.)
Don't forget the technology is not ready yet - it would be a lot harder than following the blueprints and building it naval ship style. Specific nukes would have to be developed for this project, nuclear fuel to be diverted from military uses, the environmental risks be measured and, possibly, an acceptable death toll would have to be determined. An astronaut blown to pieces is a very different thing than a mutant boy half a planet away whose lack of luck can be somewhat blamed on increased environmental radiation.
Orion is a great idea. Perhaps some aspects of it could be salvaged, but I seriously doubt we will see one ground-launched unless we develop pure fusion bombs. OTOH, if we are to bang our heads developing pure fusion bombs (which we can agree are a very bad idea), we could as well develop some other form of propulsion, nuclear fusion or not.
As for the number of nukes, just imagine how many a small fleet of them would require to haul itself around the solar system and other uses. Launching them (and their nukes) would be the easy part.
Orion is insanely cool and I am a bit ashamed we cannot build one, but I am not attached to it in any special way. This is not the way to go. It was not practical in the 50's and it's not practical now. We still must find a better way.
Huh? Values I've seen talks about a nuclear explosion around per second. You'd need a few minutes to reach LEO.
>>nuclear fuel to be diverted from military uses
http://en.wikipedia.org/wiki/Enriched_uranium
"The decommissioning programme of Russian nuclear warheads accounted for about 13% of total world requirement for enriched uranium leading up to 2008."
Etc.
(And of course it isn't a simple decision. Few interesting ones ever are.)
This is the second discussion in a short time where you obviously don't know anything at all but still write.
Personally, if I don't know anything about a subject, I just read and/or ask. Since I know my opinions will change when I know more, anyway.
http://www.alternatehistory.com/gateway/essays/OrionProblems...
The main problem is the fact that hydrogen bombs sans fission trigger turned out not to be possible [] which increases the amount of radiation released per launch from "modest" to "really quite excessive".
[] Or if they are possible then the folks who know how to build them certainly aren't interested in letting on. There'd be nothing worse for nonproliferation than hydrogen bombs without a U or Pu trigger.
Can you get me a REAL reference for "really excessive" radiation? IIRC, it contradicts both Dyson's son's book and most everything else I've read.
Edit: The Wikipedia page on project Orion (http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsi...) contradicts the claim that the radiation estimation is based on fusion only bombs. ("Freeman Dyson, group leader on the project, estimated back in the '60s that with conventional nuclear weapons, that each launch would cause on average between 0.1 and 1 fatal cancers from the fallout"). Also see "Edit 2" below. That fits with my memories, too. A serious error on the page -- to make a point... a pity, the author was obviously knowledgeable but seems dishonest. (I won't bother checking the rest of the reference, if that got through.)
Regarding costs, the Orions were thought to be built like a water going ship out of steel. That means orders of magnitudes less cost. Also, many problems just go away in designing equipment if you can throw weight at it (common example is heat distribution.)
(Was there even serious discussion about making ion drive research in the 1960s? Ah, another thing NASA should have founded -- but used all the money for the shuttle instead. :-( )
Also, the whole point with Orion was that you could literally go in person all over the solar system 30+ years ago -- which we still won't do inside decades...
Edit 2: Also from the Wikipedia page discussed in the edit above:
The fallout for the entire launch of a 6000 short ton (5500 metric ton) Orion is only equal to a ten-megaton (40 petajoule) blast, assuming the use of pure fission weapon-type nuclear explosives.
With special designs of the nuclear explosive, Ted Taylor estimated that it could be reduced tenfold, or even to zero if a pure fusion explosive could be constructed
Imagine if the moon had been several times bigger -- it would have an atmosphere, and thanks to panspermia might even have picked up enough life from Earth to give it a breathable atmosphere. The Apollo Project would have immediately been followed by a project to kill and eat the local wildlife to see what it tastes like. Or suppose we'd evolved on a moon of a Jupiter-like planet in the habitable zone -- there'd be a whole bunch of other equally habitable moons just a short flight away.
Instead we're stuck on a big rock, looking at a bunch of other rocks which are fairly useless to us. Sigh.
Maybe the economic hurdles are the limiting factors? Economics seems to be closely related to game theory. I bet a lot of the principles apply to all civilizations.
They talked of building the Orion the same way as submarines, iirc. I've read Henry Spencer argue that modern rockets and payloads are so expensive to make because they have to save on every gram.
Not near my planet, please.
Unfortunately, it would be politically infeasible.
The problem is that wouldn't have proved the prowess of US or Soviet technology.
Even in the case of nuclear war, it's much easier to detect and destroy an incoming nuke from another planet than it is to hit one that makes its transit in 5 minutes. Especially if information about the nuke is transmitted at the same time as the nuke.
Also, once we make that first "leap across the black" to colonizing another planet, theoretically the next, further leap, will be easier/less daunting.