FalconFly
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April 16, 2014, 08:04:48 PM Last edit: April 16, 2014, 08:16:16 PM by FalconFly |
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The current record for time spent in space on a single mission is 15 months - the astronaut in question is still alive at age 71 with no health problems. The current record for cumulative time spent in space over multiple missions is 2.2 years. Sergei Krikalev is now 55, also with no health problems. 18 months isn't much of a stretch by comparison. Bare in mind none of these long missions ever left earth magnetic field, which provided for the vast majority of radiation protection. The health of these persons (after returning to earth) was everything but stellar despite daily training - and required months of recovery (most credited to the effects of zero gravity). Leave the earth magnetic protection and you're in entirely different waters, requiring massive shielding which noone has ever sent to space so far (not even anything close to it). Everything in existence concerning this issue are mere design concepts not even proven to reliably work as desired. Whatever it will be, will require modular assembly in space due to the hefty mass we're talking. PS. That MarsOne design study image posted on the previous page wouldn't even afford safe passage to the moon in terms of radiation protection. An 18 months trip in that little critter would resemble a death sentence, in case of intensive solar flares likely to occur even during time-of-flight. There are good reasons space-used computers are powered by old-gen, especially hardened and manufactured ICs and RAM components, which need to be built using old nanometer masks for robustness. The radiation would easily and quickly interfere with and/or destroy the modern 22nm chip designs we're used to. The hardened designs are the only ones tough enough to withstand the radiation for a limited time, and even these need external shielding packages and redundancy to achieve their mission. Not a smart plan trying all that on a human... PPS. That 6 Billion $ that I found mentioned somewhere in the thread are downright bizarre for a manned mars mission. Multiply it by at least 100x and you're getting into more realistic regions.
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dogechode
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April 16, 2014, 08:26:45 PM |
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That 6 Billion $ that I found mentioned somewhere in the thread are downright bizarre for a manned mars mission. Multiply it by at least 100x and you're getting into more realistic regions.
I think the one they are referring to was a plan to send like 4 or 6 people with very limited equipment and totally dependent on receiving continuous supplies from Earth. Then they would keep sending a few more people with additional equipment on subsequent trips and build up slowly. 6 billion could easily do the first leg of that. The only problem is I think they'd rape and kill each other about 2 months into the mission. As far as the radiation - why can't we create shielding to prevent this? Why not construct a massive (and well shielded) ship IN SPACE, use a smaller ship to fly up to it (so you dont have to worry about getting the massive heavy ship out of the earth's gravity) then fly the giant ship to Mars orbit, and land in the smaller ship? It could be done.
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Spendulus
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April 16, 2014, 09:46:09 PM Last edit: April 17, 2014, 01:15:05 AM by Spendulus |
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That 6 Billion $ that I found mentioned somewhere in the thread are downright bizarre for a manned mars mission. Multiply it by at least 100x and you're getting into more realistic regions.
I think the one they are referring to was a plan to send like 4 or 6 people with very limited equipment and totally dependent on receiving continuous supplies from Earth. Then they would keep sending a few more people with additional equipment on subsequent trips and build up slowly. 6 billion could easily do the first leg of that. The only problem is I think they'd rape and kill each other about 2 months into the mission. As far as the radiation - why can't we create shielding to prevent this? Why not construct a massive (and well shielded) ship IN SPACE, use a smaller ship to fly up to it (so you dont have to worry about getting the massive heavy ship out of the earth's gravity) then fly the giant ship to Mars orbit, and land in the smaller ship? It could be done. Sure you can do that. You just need to get the materials for the 'massive ship' from the moon. And that puts you right back at robotic lunar exploitation as the primary and first goal necessary for solar system exploration and colonization. But this is a self reinforcing cycle - as soon as you think in terms of "massive ships" then you need off-Earth fuel and oxygen generation systems. That is only possible by decomposing lunar water deposits into h2 and o2. We don't KNOW HOW to do that. But the deposits are there, deep in craters within craters where the sun has never shined. Crater Hermites, by the N. Lunar Pole. Of course for ANY solar system exploration, if manned, these fuel and oxidizer supplies would be virtually necessary as opposed to lifting them off Earth in rockets. But for trips of 8-18 months (Mars is 8 months, not 18, if the optimal orbital transfer is chosen) systems like The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) are much preferred. There has also been development recently of what is best dubbed a "force field" that would surround a spacecraft and protect it from the solar blasts. Sort of like a miniature Van Allen belt. So we can learn to do these things in smart ways, if the research continues. But we are not really there yet. From my point of view there is nothing wrong with thinking in terms of 50-100 years for serious Mars exploration. But that is so long a period of time for computer tech, that we may find our brains in machines on mars and the idea of capsules supporting meatspace being laughed at, long before the capabilities exist to easily get to such places. Mars, incidentally cannot support terraforming without first building some kind of planetary radiation shield like the Van Allen belts. In their absence, O2 strips to ions recombines and is carried off into space. If Mars were given a 3 psi atmosphere mostly O2, in ten thousand years it would be lost to space. Very interesting place, for sure, but if we humans go there, we go there with our meatspace cans and suits.
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dogechode
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April 17, 2014, 01:51:26 PM |
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Well initially they would have to build structures to live and work in, and use suits any time they go outside. Clearly they aren't going to be able to terraform it in a matter of months; it would take decades at least. But also it would be a big step to just get started already.
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bryant.coleman
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April 17, 2014, 02:47:58 PM |
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Well initially they would have to build structures to live and work in, and use suits any time they go outside. Clearly they aren't going to be able to terraform it in a matter of months; it would take decades at least. But also it would be a big step to just get started already.
Not only it will take months of time, but also it will take tens of thousands of workers as well. The cost of transporting 3 astronauts to Mars stands at $100 billion. Imagine the cost of transporting tens of thousands of them. ![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
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Balthazar
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April 17, 2014, 03:03:08 PM Last edit: April 17, 2014, 03:25:03 PM by Balthazar |
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This is a disadvantage of the moon. Mars has a persistent (albeit thin) atmosphere, the radiation dose on the surface is not significant. They would only need shielding on the outward trip. As I have already stated, a one-way trip to Mars will take 18 months. I don't know whether the human body can endure that much cosmic radiation. No one has ever been exposed for that long. There are combinations of genes which have enhanced resistance to ionizing radiation. If radiation level in your environment is greater than average, then natural selection of resistant combinations will happen. There are many examples... Citizens of northern Iran (Ramsar city) are constantly exposed with gamma radiation at level ~4 mR/h which is ~4 times higher that average level of gamma radiation on the Chernobyl NPP (~1.2 mR/h on the roof of the sarcophagus over a former 4th reactor building). These people are resistant to these levels of radiation, their blood demonstrates an absence of pathologic changes even at much higher levels of exposition dose. http://en.wikipedia.org/wiki/Ramsar,_Mazandaranhttp://upload.wikimedia.org/wikipedia/commons/0/0e/Ramsar_radiation.jpgAccording to the results of the experiment on voles in Chernobyl, ~26 generations is required for adaptation of regular population. So it seems that it would be cheaper to find resistant combinations and use them for this mission.
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dogechode
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April 17, 2014, 03:22:15 PM |
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Reproduction in space or on the moon/Mars may also be a problem. They have done experiments at the space station (obviously not with humans) that have shown that the lack of gravity in space appears to cause some real problems for a developing fetus. It isn't clear yet whether low gravity will have the same issues.
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supernovax
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April 17, 2014, 03:24:30 PM |
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Reproduction in space or on the moon/Mars may also be a problem. They have done experiments at the space station (obviously not with humans) that have shown that the lack of gravity in space appears to cause some real problems for a developing fetus. It isn't clear yet whether low gravity will have the same issues.
Why not use artificial gravity? The gravity in moon is 1/6th of earth and in mars 2/3rd. I think 2/3 is not a problem.
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bryant.coleman
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April 17, 2014, 03:42:52 PM |
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Why not use artificial gravity? The gravity in moon is 1/6th of earth and in mars 2/3rd. I think 2/3 is not a problem.
Artificial gravity is achieved through either using the centripetal force or the linear acceleration. Both have their own disadvantages and both can cause health issues in the long term.
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Schleicher
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April 17, 2014, 04:42:14 PM Last edit: April 17, 2014, 05:07:20 PM by Schleicher |
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spin at the right speed and your body would have no way of telling that it wasn't on Earth
Yeah, but that's only true for big structures, like 1km diameter. Otherwise your head will feel a different gravity that your feet. Or you will fall over if you try to lace your shoes. Something like this would be nice: http://en.wikipedia.org/wiki/Stanford_torus
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Spendulus
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April 18, 2014, 04:47:50 AM |
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spin at the right speed and your body would have no way of telling that it wasn't on Earth
Yeah, but that's only true for big structures, like 1km diameter. Otherwise your head will feel a different gravity that your feet. Or you will fall over if you try to lace your shoes. Something like this would be nice: http://en.wikipedia.org/wiki/Stanford_torusYes, this is quite possible. First the Lunar robot exploitation systems. From your link. The torus would require nearly 10 million tons of mass. Construction would use materials extracted from the Moon and sent to space using a mass driver. A mass catcher at L2 would collect the materials, transporting them to L5 where they could be processed in an industrial facility to construct the torus. Only materials that could not be obtained from the Moon would have to be imported from Earth. Asteroid mining was an alternative source of materials.[10] General characteristics Location: Earth–Moon L5 Lagrangian point Total mass: 10 million tons (including radiation shield (95%), habitat, and atmosphere)...
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bryant.coleman
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April 18, 2014, 06:50:46 AM |
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Can you expand on the disadvantages? (apart from all the disadvantages associated with large mechanical systems) And health problems? An accelerating reference frame is physically (not just biologically) indistinguishable from a gravitational field - spin at the right speed and your body would have no way of telling that it wasn't on Earth, so no long term health effects.
Here: Yeah, but that's only true for big structures, like 1km diameter. Otherwise your head will feel a different gravity that your feet. I don't think that a space shuttle with 1 km diameter can be ever constructed. Even if such as structure is some how constructed, it will be near impossible to take it to the Mars.
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Balthazar
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April 18, 2014, 06:56:44 AM |
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It's obvious that such structures should be built directly in the space... Using parts delivered from the earth. ![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
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supernovax
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April 18, 2014, 07:46:52 AM |
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You only need the rotate where the astronaut stays. And you don't need to create a 1km circumference structure, only part of it. The only important is its 1km from the center of rotation to the other end where the astronauts stays and have it attached to the main spacecraft and have it rotate. The main spacecraft will not rotate only the living module. With this design you can even make 10km from the center of rotation to the living module with way less material.
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bryant.coleman
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April 18, 2014, 10:26:02 AM |
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You only need the rotate where the astronaut stays. And you don't need to create a 1km circumference structure, only part of it. The only important is its 1km from the center of rotation to the other end where the astronauts stays and have it attached to the main spacecraft and have it rotate. The main spacecraft will not rotate only the living module. With this design you can even make 10km from the center of rotation to the living module with way less material.
But still it will be a huge structure, unlike anything which has been built so far. And also, how to make it rotate? It will be a hell of a task to get this giant structure rotate at the right pace!
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dogechode
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April 18, 2014, 01:53:24 PM |
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What's funny to me is all the moon nuts that keep trying to respond to every single idea by saying "See! that's why you need a moon base!" We wouldn't HAVE to use the moon to build things in space, you just want a damn excuse to build a colony up there. The problem is everyone there would go freaking nuts and want to go back to earth and that's going to be a problem after their bodies have atrophied and lost bone mass from being in extremely low gravity for months/years.
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Spendulus
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April 18, 2014, 05:35:10 PM |
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What's funny to me is all the moon nuts that keep trying to respond to every single idea by saying "See! that's why you need a moon base!" We wouldn't HAVE to use the moon to build things in space, you just want a damn excuse to build a colony up there. The problem is everyone there would go freaking nuts and want to go back to earth and that's going to be a problem after their bodies have atrophied and lost bone mass from being in extremely low gravity for months/years.
Actually, you missed my point. I've used the phrase "robotic moon exploitation" and see little use in a human presence on the moon.
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supernovax
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April 18, 2014, 06:10:05 PM |
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Manned mars mission or asteroid mining is very hard and very expensive without moon exploitation or space elevator.
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Kiki112
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April 18, 2014, 11:27:20 PM |
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Manned mars mission or asteroid mining is very hard and very expensive without moon exploitation or space elevator.
but couldn't it pay itself out?
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dogechode
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April 19, 2014, 12:24:14 AM |
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Manned mars mission or asteroid mining is very hard and very expensive without moon exploitation or space elevator.
I don't see how they're related. A few people keep trying to force the argument that like the moon is some necessary precursor to a mars mission. It isn't. Whatever it would cost to get some kind of moon base, whether manned or completely automatic (which I seriously doubt could be possible any time soon, it would break down all the time and need people to fix things) anyways whatever it would cost, it must be cheaper to just go straight to mars. I think given the right planning, they could build a lot of what they need on site. Sure we'd need to send some very complex things and starter supplies but I still see no reason why some moon base needs to come first.
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