Water on the Moon, Data from multiple missions seems to indicate... |
Water on the Moon, Data from multiple missions seems to indicate... |
Sep 24 2009, 12:23 AM
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#1
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Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
This probably deserves it's own thread. Seems the evidence is not specific to only one mission...
space.com article: http://www.space.com/scienceastronomy/0909...-discovery.html -------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
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Sep 24 2009, 07:43 PM
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#2
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Solar System Cartographer Group: Members Posts: 10226 Joined: 5-April 05 From: Canada Member No.: 227 |
One litre per cubic metre... that sounds way too much, but it's pretty hard to get a handle on amounts here. 5 km/hour - can we extract the water molecules as fast as we can drive? That might be the limiting factor.
I'm not trying to sound too negative here, but I'm not convinced we could use the water that is being described at low latitudes. But concentrate it in cold traps, and I could see that being useful. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PDF: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Sep 24 2009, 08:39 PM
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#3
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Founder Group: Chairman Posts: 14434 Joined: 8-February 04 Member No.: 1 |
Like Greg - I'll say up front, I hope I've not screwed up any decimal places here.....
1kg of water per m^3 of soil. They said figures like 1mm, 2mm, a few mm. I'll go with 2mm. Thus - 1000 x 1000 x .002 m (i.e. farming 1 sq km) - is 2,000 kg of water. Looking at something like the Mars Direct ISRO numbers - taking 8T of H2 and working with in-situ CO2 to make methane and O2. - 8T of H2 as water would be a further 64T of O2 - for a total of 72T of equivalent water, as it were. That's 36 sqkm of farming, or, from a landing site - every scrap of surface regolith to a radius of 3.4km Alternatively - taken an MSL sized rover - with some sort of soil harvesting combine harvester style rig on front - shall we say 3 x 1m wide grabbers ( like a big gang-lawn mower). It would have to travel a total of 12,000km of 3m wide stripes to cover 36 sqkm. Quite by chance - that's about 1000km further than a circumnavigation of the whole moon. At a brisk rover of, say 2.5m/sec (just over 5mph) - operating a 50% duty cycle for the day/night cycle - 110 days. But of course, you can't have a rover that just end up dragging a 70 ton sack - it'll have to get it bit, return it to be stored, go get some more, return it. Say you farm a 6km square, and can get one 3m x 6,000m stripe in one 'store'. It would be an average drive out of 3km, an average drive back from the end of 6.7km. Plus farming of 6km. 2000 times - 31,400km. Basically - a year of driving. Harvesting at that higher figure, though, of 2.5m/sec - perhaps taking the top cm of soil (can't imagine how you'd take the top 2mm) - and a regolith density of 2.9g/cm^3 - that, amazingly, is 4.5 CuM or 13 tons of regolith per minute, producing (as only 1/5th of our 1cm harvest is 1% water) basically, 1 litre per minute. I have no idea what sort of energy will be involved in getting that water out. Latent heat of vaporization is 2257 kJ/kg - 37 kWatts of energy required. (330x the RTG power of MSL, or a solar array about 9x9m at 30% effic) As a comparison - to get 72,000kg of water up at Phoenix's landing site - taking, say, 30cm trough, at 500kg / m^3, at 3m wide, is only 160km of trough - 75x less than the lunar combine harvester. I'm not convinced we could use the water that is being described at low latitudes. Nor me. Interesting - but not a resource. Cool though. I want my solar powered MSL sized water farming soil munching robot |
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Sep 24 2009, 11:56 PM
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#4
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
I want my solar powered MSL sized water farming soil munching robot ...known as "Thirsty" for short... -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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