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#26 Re: Life support systems » Apartment Concept » 2008-05-07 19:15:37
What concerns me about placing in on the ground is the risk of puncture of a pressurized plastic exterior
Oh I see, the poles relieve the outer shell of responsibility for any forces other than containing the internal pressure. I guess I've always thought that the shell is going to have to be so strong (plastic, glass or advanced composite) that it would be able to help out structurally as well. I must admit though that I haven't done any analysis.
I'm also unsure as to the depth or soil. I've heard it's about 10cm. I've also heard that the fractured bedrock below is very difficult excavate (basalt?). Is this true?
I think it depends on the location. Martian geology is quite diverse. Do you have a particular location in mind?
I was wondering about anchoring a dome at the perimeter into martian bedrock. Does this seem practical?
It's a popular scenario, but I'm not sure that anyone has researched just how practical it would be. Or even if we have the data we'd need to say definitively.
When I imagine dome construction. I imagine a steel (or carbon fiber) net anchored to bedrock, with the plastic shell (or balloon) underneath. Once you create any reasonable air pressure underneath the shell, the shell will inflate to whatever constraints the net places on it.
I've also been wondering about a 'heavy' dome. It would have glass panels, with a metal frame. Pressure would ensure the panels were sealed in plass. The weight of the dome along with perimeter and vertical interior anchors would hold it to the ground.
In that scenario, the glass panels wouldn't be helping hold down the dome, so the metal framework would have to be very heavy. I think I read here somewhere that you'd need 3 ft of regolith over the whole dome to counteract the internal pressure. One idea that was mentioned is to use 3 ft of water (which becomes ice, of course) instead - which gives some translucency and also provides some protection against the harsh environmental radiation.
#27 Re: Life support systems » Apartment Concept » 2008-05-07 15:34:05
Hi akwx128, welcome to New Mars!
What a great image. Thank you for posting it. The pill shape is very sensible for containing the very high relative pressure inside. That is one of the problems with domes - how to keep them anchored to the ground with all that pressure under them. I wonder, though, about the practicality of the two legs. If the pill were just resting directly on the ground - or even partly buried - you'd still get most of the benefits of the design.
For dust removal, maybe you could have simple robots, like those ones that clean pools.
#28 Re: Interplanetary transportation » Relativity of light - light at light speed » 2008-05-06 08:45:29
The Wikipedia article isn't too bad either 
http://en.wikipedia.org/wiki/Introducti … relativity
Basically you have to use the Lorenz transform to answer questions about what one reference frame looks like from another reference frame. The math isn't too bad. Intuitively, it just makes c into infinity and bends everything else accordingly. The hard part is understanding that there is _not_ an absolute reference frame - no reference frame is preferred over any other.
#29 Re: Human missions » Mars Exploration Consortium. » 2008-05-05 17:40:21
The only half reasonable scheme I've heard for asteroid mining is for the mining of water to bring to LEO. It could immediately be profitable because it can be used as reaction mass to deorbit stuff (like satellites), and later, it could be split to make a rocket fuel depot in orbit - and, of course, it could be used to resupply orbital hotels, etc. Since it costs $10,000/lb to get stuff to LEO, anything _useful_ already in LEO is worth at least $10,000/lb.
#30 Re: Science, Technology, and Astronomy » Magnetic Atoms Of Gold, Silver And Copper Have Been Obtained » 2008-05-04 15:54:56
Well, http://en.wikipedia.org/wiki/NVRAM for one.
But really, we don't understand magnetism as well as we do, say, electric charge. This sort of breakthrough could open up a whole world of applications. The first thing that comes to mind to me is the generation of high strength magnetic fields, which right now is materials-limited (the electro magnets explode if you try to generate too high a magnetic field), and power generation (you rotate wires in a magnetic field to generate electricity), but every new physics phenomena eventually becomes an industry (or two
#31 Re: Meta New Mars » Spammer » 2008-05-01 19:59:24
Electronic gadget spammer ...
#32 Re: Intelligent Alien Life » Why is the Universe silent? » 2008-05-01 15:01:39
Perhaps you read about the famous Miller-Urey experiment?
#33 Re: Intelligent Alien Life » Candor Chasma » 2008-05-01 10:32:41
Definitely here.
In fact, why not start a thread here called "Zydar's Visual Research" and post all your findings there. So people won't miss anything.
#34 Re: Terraformation » Minimal Martian Terraformed Atmospheres » 2008-04-27 11:53:56
Redoing the calculations you get a very acid solution for small amounts of water
Well, that's really exciting then. So warming to the point of allowing liquid water for any significant period should set off a nice positive feedback that liberates, say, at least 200 mbar of CO2? And this mechanism (liberation from carbonate by acid waters) hasn't been taken into account by previous terraforming estimates, so its a big bonus.
As for your second link, I apologize, but I'm not sure I get the connection...?
Oh, I just wanted to make sure you'd seen the idea of using the carbon of Phobos to make ice deposit impactors. I hadn't seen it before, and I think it might be a way of getting things going relatively inexpensively.
#35 Re: Terraformation » Minimal Martian Terraformed Atmospheres » 2008-04-26 23:41:49
This analysis ...
http://chapters.marssociety.org/winnipeg/soil.html
... seems to suggest that adding water to Martian regolith will get you a base, not an acid.
As a related aside, you might want to put this idea in the back of your mind ...
#36 Re: Science, Technology, and Astronomy » ID is the best theory at the moment. » 2008-04-26 14:44:21
Name me one GOOD piece of Evidence for Evolution.
If you are actually interested, you can read about the evidence here ...
29+ Evidences for Macroevolution
http://www.talkorigins.org/faqs/comdesc/
#37 Re: Science, Technology, and Astronomy » ID is the best theory at the moment. » 2008-04-26 09:50:40
Also, only religious fundamentalists call evolution "Darwinism." As if the theory could be reduced to one person. It's like calling the theory of gravity "Newtonism." And they only do it so that they can attack Charles Darwin as a person (he wasn't exactly a saint) instead of the theory.
#38 Re: Intelligent Alien Life » Why is the Universe silent? » 2008-04-19 17:00:21
Recent article on the Fermi paradox ...
...
“The Earth’s biosphere is now in its old age and this has implications for our understanding of the likelihood of complex life and intelligence arising on any given planet,” said [Prof.] Watson.
...
#39 Re: Human missions » Venus First » 2008-04-18 22:25:45
Ok, what do we do about the acid?
Presumably your going to want to use as much carbon in your structures as possible, how does it react with acid, and what can we use to protect it and other materials?
That was discussed a little bit here ...
Floating Venusian cities or Venus vs Mars vs Titan revisited
http://www.newmars.com/forums/viewtopic.php?t=5322
... you can use a diamond coating ( e.g., see http://www.sandia.gov/media/diamond.htm ). Also, the sulphuric acid is very concentrated and actually isn't as reactive as the more dilute kinds (i.e., diluted with water). It would be a problem analogous with rust rather than with clouds of lava that dissolve your floating city.
#40 Re: Terraformation » Impractical way to cool Venusian Atmosphere. » 2008-04-18 22:01:01
Make so much ballons that covered a lot of the planet. The ballons will be coated with a high reflection material (like aluminium) that should make Venus to reflect a lot of solar light into space.
Similar ideas have been discussed for cooling the Earth ...
Teller et al., "Global Warming and Ice Ages: Prospects For Physics Based Modulation of Global Change," DOE Technical Report, August 1996
http://www.osti.gov/accomplishments/doc … CC0229.pdf
... it may be that a solar shade/scatter cloud at the Venus-Sun L1 point is more efficient long term (it certainly requires less mass).
#41 Re: Terraformation » Terraforming the Moon - Your opinion, please » 2008-04-18 20:53:38
Hi Spaniard, welcome to New Mars.
I agree that giving the moon an atmosphere is a good idea.
You have some interesting thoughts on sources of xenon. Although iodine is rare, yours is the first proposal I've heard that could possibly generate the required amount of xenon.
Transmutation is fairly energy intensive though. It might be more practical to have an oxygen-based atmosphere and just use that energy to replace any losses, say by splitting water from Ceres.
#42 Re: Human missions » Venus First » 2008-04-17 23:22:44
Venus does have a nasty gravity problem. The further we can live out of the gravity well, the better, in the long run.
#43 Re: Unmanned probes » Hayabusa - JAXA asteroid rendezvous and sample return » 2008-04-17 12:30:21
Talk about Murphy's law. It really highlights how impressive achievements like the Mars rovers are.
#44 Re: Pictures of Mars » Astronomy from Mars. » 2008-04-17 12:26:57
Now here's a question for Martian astronomers. On Earth the brightest object in the sky after the Sun and Moon is Venus. Will Earth be the brightest object in the Martian sky after the Sun, Phobos and Deimos - or will it be Jupiter?
When this image was taken in 2003 ...
http://www.msss.com/mars_images/moc/2003/05/22/
Earth had an apparent magnitude of -2.5, while Jupiter was at -1.8. I think this is fairly representative of the general situation. However, I seem to recall reading that Jupiter will be brighter on occasion.
#45 Re: Human missions » Venus First » 2008-04-16 09:48:16
It is quite possible that, within the next 50 years, carbon fiber and CNT fiber composites will become the predominant building material in developed nations. They are very strong, and will eventually become very cheap.
#46 Re: Space Policy » Sign The Space Petition » 2008-04-14 09:07:31
Maybe it'll be laughed at less if there are a million signatures?
#47 Re: Terraformation » Soletta » 2008-04-13 20:57:20
The conventional proposal is Aluminized Mylar at 4 g/m^2.
Of course if you had that sort of budget it would be better used establishing a space manufacturing infrastructure then using the last couple of hundred billion to build the mirror.
I wrote a bit about microterraforming here ...
http://www.newmars.com/forums/viewtopic.php?t=5499
#48 Re: Terraformation » Soletta » 2008-04-13 15:35:26
Zubrin estimates that the required mirror would mass 200,000 tons ...
http://www.users.globalnet.co.uk/~mfogg/zubrin.htm
Suppose we could get launch costs to mars high orbit down to $100,000/kg then the cost just to launch would be $20 trillion. That's about 1% of global GDP each year for 20 years.
#49 Re: Water on Mars » Where is this ocean gone? » 2008-04-13 13:23:32
I think some of the water did freeze before it evaporated.
The question is, is it gone or sill there?
Hi Vincent, welcome to New Mars.
Here are some maps made by the Mars Odyssey probe showing the mass fraction of water in the first meter (3 ft) or so of Martian soil ...