Freethought & Rationalism Archive

fando · 11-17-2002, 01:20 AM

I think lethal radiation exposure is the second most challenging obstacle to extraterrestrial colonization after water scarcity. IIRC, two months in the local neighborhood without radiation shielding increases the cancer risk to roughly that of a lifetime smoker doing one pack a day.

Quote:

(I saw an article about a new material which provides the protection of a conventional lead reation suit for a fraction of the wieght, and thus size, but I can't remember where)

This material is <a href="http://www.radshield.com/" target="_blank">Demron</a>. <a href="http://www.newscientist.com/news/news.jsp?id=ns99993050" target="_blank">Here's an article</a>. Unfortunately, I think Demron is not what it seems. A <a href="http://science.slashdot.org/comments.pl?sid=45062&threshold=-1&commentsort=0&tid=126&mode=thread&cid=4673657" target="_blank">poster</a> on slashdot.org looked over their <a href="http://www.radshield.com/Demron_Test_Results.pdf" target="_blank">test results (PDF)</a> and discovered some very troubling information that screams fraud.

In theory, I believe that we have the capability to put a colony in a Lagrange point. But, I'd rather have a real engineer with real space exploration experience making these estimations.

Jackalope · 11-17-2002, 05:46 AM

If you're all hot to go to Mars, then you need to check out the Mars Society's page:
<a href="http://www.marssociety.org/" target="_blank">Mars Society</a>
A lot of these folks are from the old Mars Underground conferences. Some of their impetus was frustration with the idiocy at NASA.

The two conferences to go to are Space Access and Mars Society. While NASA sends people to these, most of the presenters are independant.

Janaya · 11-17-2002, 06:42 AM

I think that Mars colonization should come first. We could manufacture our own rocket fuel there, a huge plus. Settling Mars has obstacles but I don't think that any of them are show stoppers. A settlement away from Earth would drive innovation and scientific discovery and Mars is the best candidate. Why bother with space colonies when we have a whole planet at our disposal? I think we should eventually entertain the idea but it would be far easier and far cheaper to settle Mars.

Just my two cents.

Island3 · 11-17-2002, 10:08 AM

Quote:

Originally posted by Chip:
Hi Island3,

Nope, I think I missed the latest version of High Frontier. Can you give me more concrete reference? I suspect it is a book. Is there a review anywhere?

TIA, Chip

<a href="http://www.ssi.org/high-frontier.html" target="_blank">Here</a> we go.

And <a href="http://www.amazon.com/exec/obidos/tg/detail/-/189652267X/qid=1037560167/sr=8-2/ref=sr_8_2/103-6635211-7231064?v=glance&s=books&n=507846" target="_blank">here</a> we go again.

American Agnostic · 11-17-2002, 06:46 PM

Quote:

I think that Mars colonization should come first. We could manufacture our own rocket fuel there, a huge plus. Settling Mars has obstacles but I don't think that any of them are show stoppers. A settlement away from Earth would drive innovation and scientific discovery and Mars is the best candidate. Why bother with space colonies when we have a whole planet at our disposal? I think we should eventually entertain the idea but it would be far easier and far cheaper to settle Mars.

That's a very good point. If you wanted to produce consumer goods on a free-floating space colony you would need to have raw materials shiped into so that you could build them(the raw materials for some things like organicly based plastics could be produced at the colony but you would need to ship in things like metals and anything else that you couldn't obtain from plants and animals). Even assuming 100% efficent recycling of materials you's still need to bring in raw materials to inlarge your infrasturcture (building materials for houses other than wood). A colony on Mars, the Moon, or any other celstial body would be able to extract the all the raw materials they need from the planet. Only colonies on a planet would be able to become truely self-sufficent in that they would be able to produce all the raw materials they need (organic or inorganic) right at the colony.

Dark Jedi · 11-17-2002, 10:00 PM

Quote:

Originally posted by enigma555:
The other side of that coin, Demos, is that fuel isn't exactly in abundant supply on the moon as far as we know.

Well, actually it is. The sunlight exposure on the moon is equal to that of open space at earth orbit.

A simple railed magnetic accelerator could easilt provide the initial boost sufficient for moon escape velocity. It could likely be made sufficient (with aiming) for the entire moon-earth flight. No return fuel needed. Imagine the payload capabilities if the fuel cells were collapsable, to be re-filled in earth orbit for the return trip.

Hmm. I think my story groweth.

Dark Jedi · 11-17-2002, 10:03 PM

Quote:

Originally posted by American Agnostic:


That's a very good point. If you wanted to produce consumer goods on a free-floating space colony you would need to have raw materials shiped into so that you could build them(the raw materials for some things like organicly based plastics could be produced at the colony but you would need to ship in things like metals and anything else that you couldn't obtain from plants and animals). Even assuming 100% efficent recycling of materials you's still need to bring in raw materials to inlarge your infrasturcture (building materials for houses other than wood). A colony on Mars, the Moon, or any other celstial body would be able to extract the all the raw materials they need from the planet. Only colonies on a planet would be able to become truely self-sufficent in that they would be able to produce all the raw materials they need (organic or inorganic) right at the colony.

Hmm.. Heinlein has the moon rock crystals being a source of water. Anyone know what the ratio of water to tonnage of rock would be? How feasable, really, is this concept?

American Agnostic · 11-18-2002, 02:36 AM

Well, as was in the press a few years back, the main source of water on the moon would be from some of the polar craters that are in perminent shadow and thus never above -200F. Ice from the occasional comet impact has collected there and remained frozen over eons. Esitmates indicate that there is enough ice there to sustain a sizable colonization effert for several centuries even if none of the water is recycled! Other than that, the Moon is bone-dry. Unlike rocks on Earth rocks on the Moon contain little to no water. Moon rocks have been compared to rocks from earth that have had all the water baked out of them. Other than in the water at the poles hydrogen is ultra scarce (the Moon's gravity just can't hold on to it) and thus poses a problem since hydrogen is needed for water, the manufacture of some materials, rocket fuel, and organics to name a few of it's uses. Mars colonists on the other hand won't have this problem. We've already determined that globaly there is about 2 Lake Michigans worth of water within 1 meter of the surface and there bound to be lots more furthur down!

Chip · 11-18-2002, 05:31 AM

I believe the source of hydrogen and water for existing long range space colonization plans is considered to be the rings of Saturn. More recent findings of ice on the moon sounds promising but I doubt if we can actually place a tonnage on how much is there until we explore further.

Regards, Chip

Demosthenes · 11-18-2002, 07:28 AM

I wonder if in some far off future time, Saturn's rings will be declared to be a protected piece of estate and off-limits to mining. We could probably easily find the essentials in the earth-moon system asteriods and the asteriod belt too. If our civilization expands far enough, then we would probably start harvesting the icy comets located in far reaches of the kuniper belt and oort cloud. It all depends on how much raw materials we'll actually need and how efficently we are at using them and recycling( ie future technology can conceivably make 100% matter recycling possible). A future civilization may end up never really needing the full resources of a solar system, just a few tidbits located here and there.

If our energy needs grow fast enough, we could start tapping the sun to provide the energy, either by low orbiting satellites collecting the solar energy and beaming the energy via lasers or microwaves back to the civilization centers. I've seen schemes where one would enclose the sun in a bubble which intercepts something like 90% of the radiant energy while leaving the equatorial plane open so the planets are still illuminated. For a such Dyson bubble, we won't need to dissamble everything in the solar system, the planet mercury has enough material to do the job.

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11-17-2002, 05:46 AM	#22
Jackalope Veteran Member Join Date: Oct 2002 Location: Hayward, CA, USA Posts: 1,675	If you're all hot to go to Mars, then you need to check out the Mars Society's page: <a href="http://www.marssociety.org/" target="_blank">Mars Society</a> A lot of these folks are from the old Mars Underground conferences. Some of their impetus was frustration with the idiocy at NASA. The two conferences to go to are Space Access and Mars Society. While NASA sends people to these, most of the presenters are independant.

11-17-2002, 06:42 AM	#23
Janaya Regular Member Join Date: Sep 2002 Location: Houston, Texas Posts: 226	I think that Mars colonization should come first. We could manufacture our own rocket fuel there, a huge plus. Settling Mars has obstacles but I don't think that any of them are show stoppers. A settlement away from Earth would drive innovation and scientific discovery and Mars is the best candidate. Why bother with space colonies when we have a whole planet at our disposal? I think we should eventually entertain the idea but it would be far easier and far cheaper to settle Mars. Just my two cents.

11-18-2002, 02:36 AM	#28
American Agnostic Junior Member Join Date: Sep 2002 Location: CA, USA Posts: 56	Well, as was in the press a few years back, the main source of water on the moon would be from some of the polar craters that are in perminent shadow and thus never above -200F. Ice from the occasional comet impact has collected there and remained frozen over eons. Esitmates indicate that there is enough ice there to sustain a sizable colonization effert for several centuries even if none of the water is recycled! Other than that, the Moon is bone-dry. Unlike rocks on Earth rocks on the Moon contain little to no water. Moon rocks have been compared to rocks from earth that have had all the water baked out of them. Other than in the water at the poles hydrogen is ultra scarce (the Moon's gravity just can't hold on to it) and thus poses a problem since hydrogen is needed for water, the manufacture of some materials, rocket fuel, and organics to name a few of it's uses. Mars colonists on the other hand won't have this problem. We've already determined that globaly there is about 2 Lake Michigans worth of water within 1 meter of the surface and there bound to be lots more furthur down!

11-18-2002, 05:31 AM	#29
Chip Banned Join Date: Sep 2002 Location: Earth Posts: 382	I believe the source of hydrogen and water for existing long range space colonization plans is considered to be the rings of Saturn. More recent findings of ice on the moon sounds promising but I doubt if we can actually place a tonnage on how much is there until we explore further. Regards, Chip

11-18-2002, 07:28 AM	#30
Demosthenes Veteran Member Join Date: Oct 2000 Location: a speck of dirt Posts: 2,510	I wonder if in some far off future time, Saturn's rings will be declared to be a protected piece of estate and off-limits to mining. We could probably easily find the essentials in the earth-moon system asteriods and the asteriod belt too. If our civilization expands far enough, then we would probably start harvesting the icy comets located in far reaches of the kuniper belt and oort cloud. It all depends on how much raw materials we'll actually need and how efficently we are at using them and recycling( ie future technology can conceivably make 100% matter recycling possible). A future civilization may end up never really needing the full resources of a solar system, just a few tidbits located here and there. If our energy needs grow fast enough, we could start tapping the sun to provide the energy, either by low orbiting satellites collecting the solar energy and beaming the energy via lasers or microwaves back to the civilization centers. I've seen schemes where one would enclose the sun in a bubble which intercepts something like 90% of the radiant energy while leaving the equatorial plane open so the planets are still illuminated. For a such Dyson bubble, we won't need to dissamble everything in the solar system, the planet mercury has enough material to do the job.

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