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#1 2014-01-01 17:07:17

RobertDyck
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Site selection

Where should the first permanent human base/settlement be located? My criteria:

  • flat and smooth -- to enable safe landing

  • low altitude, at least below datum, ideally -2km -- more atmosphere provides greater protection from heavy ion Galactic Cosmic Radiation

  • close to equator, at least between northern and southern tropic, ±25.19° -- relatively warm, no winter

  • identified source of water (ice)

  • other resources

  • interesting science

One potential location is the "Frozen Sea" also known as "Pack Ice" in Elysium Planitia. The ESA team reported this in 2005. Analysis of image data showed it's 900km x 800km and an average of 45m deep. However, that's the result of studing "sploosh" craters and layered deposits. It's apparent this was formed by water, and was pack ice at one time. The feature appears to have been formed no more than 5 million years ago. However, there remains a question whether water ice still remains.
dn7039-1_250.jpg

This paper from 2010 is not encouraging. It's the result of analyzing radar data from MARSIS and SHARAD. Other papers say similar things: results are not conclusive, but results can be explained by geological features other than water ice.
http://meetingorganizer.copernicus.org/ … 10-723.pdf

SHARAD data reveal subsurface interfaces at depths ranging from ≈50 m to ≈150 m which could be interpreted as either the bottom of an ice sheet lying over bedrock, or an interface between two lava flows. Echoes have been analyzed to estimate the dielectric properties of the surface layer, and results favor the interpretation that no ice is present in the area.

Do we look elsewhere? One local individual questioned whether we need a flat, smooth location. He wants something with steep walls we can roof over easily, such as a valley or crater. Transparent plastic film that can hold in air, but let sunlight shine through. Should we look for water in a valley (vallis)? We know there's ice near the poles, such as this image of blue ice on red soil. The problem is this is near the north pole: Vastitas Borealis Crater is 70.5° North.
Water_ice_in_the_Vastitas_Borealis_crater_Mars_focuson.jpg

SHARAD has found hidden glaciers at mid latitudes. Not surprisingly, they do appear in valleys. The problem is to find one near the equator.
mars-ice-glaciers-100304-02.jpg?1292270049

Where do you recommend?

Last edited by RobertDyck (2014-01-01 19:29:38)

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#2 2014-01-01 19:50:09

SpaceNut
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Re: Site selection

http://www.wordiq.com/definition/Mars_%28planet%29

Zero elevation: Since Mars has no oceans and hence no 'sea level', a zero-elevation surface or mean gravity surface must be selected. The datum for Mars is defined by the fourth-degree and fourth-order spherical harmonic gravity field, with the zero altitude defined by the 610.5 Pa (6.105 mbar) atmospheric pressure surface (approximately 0.6% of Earth's) at a temperature of 273.01 K. This pressure and temperature correspond to the triple point of water.

Observations of the magnetic fields on Mars by the Mars Global Surveyor spacecraft have revealed that parts of the planet's crust has been magnetized in alternating bands, typically measuring 100 miles wide by 600 miles long, in a similar pattern to those found on the ocean floors of Earth.

Here is map that will help:

http://pubs.usgs.gov/imap/i2782/

Color-Coded Contour Map

mp_full.3.jpg

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#3 2014-01-02 00:02:14

JoshNH4H
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Re: Site selection

When it comes to a colony, my take is that resources are the most important thing to have around.

The most important resource (with variable availability, that is to say I'm not considering atmospheric CO2 or N2) is water.  I'm sure we've all seen this map:

Mars-GRSwatermap.jpg

What we see is that in the equatorial bands, at low latitudes the water concentration in the regolith is between 4 and 8 percent.  This does not mean water ice, this means any kind of water.  In this case it almost certainly means hydrates, which require a good bit of energy to bake the water out of.  What this means is that we want better reserves of water. 

It appears that there is probably water ice at latitudes above 45 degrees.  But this is too high to reasonably build a colony at, and the 3000 km supply lines simply aren't worth it.  This article suggests that there is water ice at the equator.

Here's something to think about:  10,000 cubic meters of water ice is 10 million kg of water ice.  If there is a reserve of water ice at 30-35% by volume, somewhere on the equator, for a 3 m deep stretch, a 100 m x 100 m square would be enough to get it.  It would probably have to be buried, but I bet these kinds of deposits dot the planet, with higher concentrations as one get farther from the equator.

The issue here is what GW calls "ground truth": These deposits are going to be extremely hard to see from orbit.  We can find places where we would strongly expect them to exist, though.  That frozen sea at Elysium is a prime example.  There are also two more-or-less equatorial areas where the concentration of water in the regolith gets up to about 8%.  This suggests that there may be sources of water in these areas which are increasing the concentration of water in the regolith.  more research is needed.

The Mars Odyssey Gamma Ray Spectrometer results are useful to look at resource concentrations  This pdf talks about the presence of various types of minerals on the surface of Mars, taken from the Mars Global Surveyor results.

Other resources of import:  Iron ore, Silica, and Bauxite or equivalent Aluminium ore.  According to the GRS results silica is distributed pretty evenly, while Iron varies between 10 and 20 percent, with the highest concentrations far to the east near the equator (Rather close to the spot of elevated water concentration around 180 degrees longitude).  I haven't seen any results on Aluminium. 

If there are any reserves of nitrates anywhere on planet those would be quite valuable.  If the MAVEN mission suggests that little primordial nitrogen has been lost, there are probably a good deal of nitrates hidden somewhere.


-Josh

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#4 2014-01-02 05:12:55

Quaoar
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Re: Site selection

RobertDyck wrote:

Where should the first permanent human base/settlement be located? My criteria:

  • flat and smooth -- to enable safe landing

  • low altitude, at least below datum, ideally -2km -- more atmosphere provides greater protection from heavy ion Galactic Cosmic Radiation

  • close to equator, at least between northern and southern tropic, ±25.19° -- relatively warm, no winter

  • identified source of water (ice)

  • other resources

  • interesting science

One potential location is the "Frozen Sea" also known as "Pack Ice" in Elysium Planitia. The ESA team reported this in 2005. Analysis of image data showed it's 900km x 800km and an average of 45m deep. However, that's the result of studing "sploosh" craters and layered deposits. It's apparent this was formed by water, and was pack ice at one time. The feature appears to have been formed no more than 5 million years ago. However, there remains a question whether water ice still remains.

If we will find ice, Elysium Planetia may be the best site (is it possible to send a Red Dragon in Elyseum Planitia with the hardware to drill 45 m deep to verify the presence of ice?)

If there is no water ice in equatorial latitude, we can imagine some form of migrating colony: a fleet of wheeled habitats that stay in Vastits Borealis Crater in spring and summer and migrate south in autumn with a water reserve for the winter.

This in the first times. When the colony will grow, we can imagine a pressurized dome around Vastitas Borealis crater, warmed via greenhouse effect douring the winter, with the ice lake partially melted that act like an heat sink, tempereting climate.

Last edited by Quaoar (2014-01-02 05:27:12)

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#5 2014-01-02 11:26:10

JoshNH4H
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Re: Site selection

Rather than make the colony mobile, if we do end up needing to get ice from vastitas borealis, wouldn't it make sense to have a small base up there with a rotating crew to oversee mining and transport operations, and send the ice straight south a couple tonnes at a time?


-Josh

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#6 2014-01-02 13:59:02

Quaoar
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Re: Site selection

JoshNH4H wrote:

Rather than make the colony mobile, if we do end up needing to get ice from vastitas borealis, wouldn't it make sense to have a small base up there with a rotating crew to oversee mining and transport operations, and send the ice straight south a couple tonnes at a time?

It may be a good option: a little tank truck to bring the ice to ice lake to the base in Elyisium Planetia that is almost 3300 km south.

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#7 2014-01-02 14:03:32

JoshNH4H
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Re: Site selection

Well if there isn't water in Elysium Planitia then there's really no reason to put the colony there.  Other equatorial regions may be better.

The real question to me is if that kind of supply chain makes more sense than dehydrating the hydrates at the equator.  I think it does, but who really knows?


-Josh

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#8 2014-01-02 14:04:05

louis
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Re: Site selection

No need to panic about water would be my view.

How much water do we need? Maybe a kg a day per person.  You don't need actually need water to wash yourself. You don't actually need water to clean clothes or clean crockery.  What you need really need water for is drinking.

A 6 person colony might use 6kgs a day or under 2000 kgs pa. Of course, though, we will have the technology to recycle most of the water we use. Simple technology is available to effect that. 
So, let's say conservatively we could get by on 500kgs for a 6 person colony.

Why not pre-land the water then in a separate craft?

Once the colony is established they can search for water - I agree we should land where we think water will be found but we shouldn't assume we can only begin colonisation if we find a water source.


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#9 2014-01-02 14:27:05

GW Johnson
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Re: Site selection

Things to worry about: 

Any base you build will require a source of fresh potable water for drinking,  and for watering crops in any sort of greenhouse.  Salt water won’t do,  because desalination is so energy-intensive,  and therefore heavyweight in required equipment.  Simple fact-of-life,  sorry.  They cannot survive,  much less thrive,  without fresh water. 

Being below a 6 mbar datum determined by the triple point does not make exposed 0 C water or ice stable.  What makes the condensed phases stable at 0 C is water vapor pressure at 6 mb.  You’ll have to cover the exposed water or ice in such a way as to let the vapor displace 6 mbar worth of atmosphere.  This will very likely impact how you go about prospecting for ice resources,  and in how you store them and ship them after you find them.

A lot of the soils seem to be very salty in one way or another.  Any water dispersed in that soil will be salt-contaminated.  Not only do you have to dig up and process an enormous soil volume to get a much smaller water volume,  you will have to desalinate that water before you can let people or crops drink it.  It sure does make sense to prospect for buried freshwater glaciers before committing to building a base.  That’s ground truth supporting an informed decision. 

I have never seen a robot drill rig.  I have seen a lot of rigs that need to pull the drill string quite frequently to replace worn out drill bits.  Less frequently,  the drill string breaks.  Can you imagine a robot that can extract the broken-off drill pipe string from way down in that well?  Sorry,  I can’t.  Men will have to do the deep drilling,  and it will take a lot longer than you expect.  Ask the oil and gas guys if that’s not the gospel truth. 

It looks like Josh’s map says an orbit inclined 40 degrees or so would take you to every possible place where there might reasonably be buried freshwater glaciers,  excepting the poles themselves.  There are several such sites,  none at high altitudes,  but several not so near the equator.  Every one of them requires real ground truth to support an informed decision about whether or not to attempt a base there.  Would it not make a lot of sense to land a crew at each site and drill for that ground truth,  before actually landing everybody plus base-building supplies at the best site?  That leads immediately to orbit-basing until you select that best site.  And that’s why I think making only one landing immediately upon arrival (from orbit or direct) seems like a silly,  wasteful idea.   

It is quite likely there will be one (and only one) government-funded mission to Mars.  That trip has to find the place to plant a base that can thrive,  or there’s no point for any of the commercial/private groups to go.   There’s lots of indirect evidence of water all over Mars,  but it’s not certainty.  Certainty requires ground truth.  Does it not make sense to plan on getting that ground truth and finding the base site “for sure” in that first (and only) government trip?  How do you get that out of a NASA flag-and-footprints stunt,  or out of a direct landing at only one site?  I don’t see much sanity in those ideas.  It’s just my opinion only,  but there it is. 

GW


GW Johnson
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"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#10 2014-01-02 16:27:03

RobertDyck
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Re: Site selection

Canadrill-1_h.jpg
Several years ago, the president of the Canadian Space Agency pushed a plan to send a Canadian rover to Mars. He wanted to include a multi-segment drill. A technology centre actually built a working prototype. Parliament never approved funding, so it died. But the prototype was built. The drill pipe was to consist of 10 segments, each 1 metre long. I saw it at a workshop at CSA headquarters in 2005. A plywood box held rock, gravel, sand, in several different layers. The idea was to test the drill with challenging conditions. It was slow: dry drilling (no lubricant) and an electric motor. It drilled through everything, and the plywood bottom of the box.

::Edit:: This image is from 2001. It shows a lander, not a rover. But at the 2005 workshop, the CSA president himself gave a speach in which he described a rover.

Last edited by RobertDyck (2014-01-02 18:57:58)

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#11 2014-01-02 16:43:58

Quaoar
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Re: Site selection

At the moment, the only place where where we are certain of the presence of water, exept polar caps, is the Ice Lake Crater: we can send a probe to test the salinity and the acidity.
In the worst case we cannot find water in equatorial latitude, we can land the first mission near the ice lake and use it for ISPP. Douring the winter, astronaut may moove sauth with the rover and explore other site.

But, in this work ( http://www.nature.com/nature/journal/v4 … 03379.html ) planetologists suggest the existence of a 800x900 km x 42 m surface ice pack in western Elysium (5° N 150° E).
It would not be difficoult for an unmanned probe to verify the claims, drilling for 1-5 meters and test the salinity and the acidity of the water.

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#12 2014-01-02 18:29:12

louis
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Re: Site selection

I think we are confusing a few things here.  To my mind the sequence should be:

1. Establish a presence on Mars. Your first location might not be the ultimate base location, although you would be aiming for a good area.  For Mission 1 there is no requirement to feed and water the crew with ISRU: plenty of supplies can be brought with the crew or pre-landed.

2.  Mission 1 can experiment with soil and food production and other ISRU techniques.

3. Begin prospecting for a permanent base site. Build in mobility. Personally I would run with electric trikes to begin with.  You can probably explore   

4. Once you have located the perfect site with good iron ore, silica and water supplies- that's where the main colonisation effort would be focussed.

I would suggest the above approach would provide the swiftest route to colonisation - it's a case of don't run before you can walk.

Robot drilling down into the regolith sounds expensive and asking for trouble. Get people on the planet and they will find the water.

Is salty water a problem?  I would have thought we could desalinate easily. Energy on the surface will not be a problem.


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#13 2014-01-02 19:20:29

RobertDyck
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Re: Site selection

I didn't want to argue this here. A discussion of whether to build a base is off topic. But...

Dr. Robert Zubrin argued in 1989 and ever since to send humans instead of robotic explorers. There are some who want to send robotic explorers only, no humans. The official line from NASA is that robotic explorers prepare the way for humans. I keep saying that Robert Zubrin's arguments were valid back then, but robotic exploration is now done. With Mars Global Surveyor and Mars Pathfinder launched in 1996 through Curiosity, and upcoming Maven and InSight, it's now done. Complete, over, succussful. Everything from now on has to be a technology demonstrator for humans. But that also means the robotic exploraton has to have actually achieved something. If you want to start over, if you want to act as if Mars has not been explored at all, that means you throw everything from MGS through Curiosity, Maven and InSight in the garbage. The only way those missions have any meaning is if we can select a site.

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#14 2014-01-02 20:45:44

louis
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Re: Site selection

RobertDyck wrote:

I didn't want to argue this here. A discussion of whether to build a base is off topic. But...

Dr. Robert Zubrin argued in 1989 and ever since to send humans instead of robotic explorers. There are some who want to send robotic explorers only, no humans. The official line from NASA is that robotic explorers prepare the way for humans. I keep saying that Robert Zubrin's arguments were valid back then, but robotic exploration is now done. With Mars Global Surveyor and Mars Pathfinder launched in 1996 through Curiosity, and upcoming Maven and InSight, it's now done. Complete, over, succussful. Everything from now on has to be a technology demonstrator for humans. But that also means the robotic exploraton has to have actually achieved something. If you want to start over, if you want to act as if Mars has not been explored at all, that means you throw everything from MGS through Curiosity, Maven and InSight in the garbage. The only way those missions have any meaning is if we can select a site.

I agree with the general thrust of your argument.

I have always said that if we can get one human on the surface for one hour we will learn more than we ever could from more than 1000 hours of robot exploration.


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#15 2014-01-04 08:14:03

Tom Kalbfus
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Re: Site selection

There is a spot just north of Olympus Mons at around 45 degrees north. I for one wonder why it is so important to avoid high latitudes, the astronauts are going to be in spacesuits anyway, and with an atmospheric pressure at about 1% of that of Earth, this limits the ability of the atmosphere to carry away heat. Also one of the advantages of high latitudes is the long days during the summer, this means greater availability of solar energy. I think 2 bases might be a good idea, one at 45 degrees north and the other at 45 degrees south, so the base personnel will just seasonally migrate twice every Martian year, once in Northern Spring and once during Northern Fall. Seems easier to go where the water is than to base at the equator and bring the water to the base, there is plenty of exploration which could be done during migration as well.

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#16 2014-01-04 12:06:47

SpaceNut
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Re: Site selection

I do not believe that desalination is that big of a deal as any process that we use to extract water will be follow by many steps to refine what we wanted from the first scoop of soil and many to follow. The soil will be a waste product for the next step and so on unit there is little waste product remaining.
Here is a batch of images of quite a veriety of solar desalination systems

The low altitude is better for protection from cosmic rays as the magnetic fields and atmosphere grants a bit more for protecting a crew.

I think that the area between the lines in this next image is where we might target.

MARS_dec12_nature.jpg

Last edited by SpaceNut (2014-01-04 14:36:43)

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#17 2014-01-04 20:37:52

louis
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Re: Site selection

I'd like to add this factor - what you might call the Mars One factor:

Let's have a location that is close to dramatic scenery. So I think that takes us to the Mars Grand Canyon or perhaps Olympic Mons (which probably doesn't look dramatic but would make a good story).

In other words we are in an age where we need to sell Mars to a rather cynical Earth-bound population.

We need Mission One to be dramatic.


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#18 2014-01-05 10:17:55

GW Johnson
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Re: Site selection

"I do not believe that desalination is that big of a deal" -- here on Earth that process is quite energy-intensive (because the process energy efficiencies are low) and the machinery is big and heavy and expensive.  Most large plants now use permeable-membrane technology,  for best efficiency and lowest operating costs,  but face frequent very-expensive membrane replacements due to its high vulnerability to clogging.  The smallest and most trouble-free machinery is also the least energy-efficient:  the vacuum-flash distillation process used on ships for about a century now. 

"Let's have a location that is close to dramatic scenery." -- actually I do agree with that,  in so far as is practical.  Part of keeping people sane is having interesting places to look at and explore. 

GW


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#19 2014-01-05 11:51:59

RobertDyck
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Re: Site selection

It's highly probable that the only fresh water ice on the planet is a polar ice cap. All other ice will be salt water. So the lowest latitude that would have access to fresh water ice would equal Mars Phoenix. When winter fell, it was encased in dry ice. The probe failed because it was crushed by several feet of solid dry ice.

Last edited by RobertDyck (2014-01-05 12:58:42)

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#20 2014-01-05 12:22:15

GW Johnson
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Re: Site selection

The image in post 1 above is called "frozen sea" or "pack ice",  located in Elysium Planitia.  If that is what it really is,  ice frozen from a now-gone sea,  it is likely freshwater ice.  That is what happens in the polar regions here.  The salty sea water freezes into ice at the surface,  leaving the salt in the unfrozen sea water below.  Excepting salt spray surface contamination,  the ice is fresh water. 

Personally,  I think the next probe to Mars ought to land on one of those supposed blocks of ice.  It should carry a drill capable of sampling 10's to 100's of meters down,  plus examples of the ISRU and ISPP gear we are contemplating.  Objective 1 - is that really the dirt-covered ice that it appears to be?  Objective 2 - if ice,  is it freshwater ice?  Objective 3 - does any of our ISRU/ISPP gear really work on Mars?  Objective 4 - what kinds of problems do we run into operating our ISRU/ISPP gear on Mars over extended periods of time?

It's just my opinion,  of course,  but not addressing these specific objectives at this oh-so-very-interesting site is another piece of prima facie evidence (among several lines of evidence) that NASA still yet has no intention of sending people to Mars. 

One could make similar cases at other interesting sites,  but I think this is one of the best.  Any base or colony we intend to plant will need water.  It's a whole lot easier to get from massive freshwater ice deposits than any other imaginable source on Mars. 

GW


GW Johnson
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#21 2014-01-06 13:58:42

Tom Kalbfus
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Re: Site selection

GW Johnson wrote:

"I do not believe that desalination is that big of a deal" -- here on Earth that process is quite energy-intensive (because the process energy efficiencies are low) and the machinery is big and heavy and expensive.  Most large plants now use permeable-membrane technology,  for best efficiency and lowest operating costs,  but face frequent very-expensive membrane replacements due to its high vulnerability to clogging.  The smallest and most trouble-free machinery is also the least energy-efficient:  the vacuum-flash distillation process used on ships for about a century now. 

"Let's have a location that is close to dramatic scenery." -- actually I do agree with that,  in so far as is practical.  Part of keeping people sane is having interesting places to look at and explore. 

GW

Desalination is easy on Mars, all we have to to is raise the temperature of water ice until it sublimates in the Martian atmosphere, then we surround the sublimating ice with a grill that is refrigerated so the water re-condenses on it as pure water ice, remove the grill and replace it with another one, place the grills with frost on it inside the habs so that the ice melts into usable drinkable water. Does this seem simple enough?

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#22 2014-01-06 14:43:46

SpaceNut
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Re: Site selection

So build a small chamber with a plate that will heat (think oven element under tray) the Mars soil to release the water at the top of the chamber feeding into the next through a damper and a cold plate at the bottom of the next chamber ( refridgerant coil cycled from the outside temp with small pump) to catch the vapor this could be a meter square cube for each perhaps even multi tray. Both chamber are fully sealed tight while in operation. Vent/pump any other captured gasses for later processing into a pressurized bottle. Next do a mineral/chemical grading check to see what we would want the heat batch to be sorted to next for further processing into the next process in insitu use.

The process can also be used for the waste water and other waste streams that contain moisture. Just place waste into a bag and place outside to freeze place frozen bag into chamber and process that same way as before.

Last edited by SpaceNut (2014-01-06 18:51:19)

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#23 2014-01-09 12:15:25

GW Johnson
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Re: Site selection

I see good ideas here for desalination by freezing,  the same way the ocean does it with polar pack ice.  The concept is easy,  getting equipment that produces mass quantities quickly is very hard.  You don't do that with "a small chamber". 

Lest you dismiss "mass quantities" as a Coneheads comedy issue,  quantify how much water you are going to need every single day to support,  say,  a dozen folks in a permanent base.  Add to that water needed for making rocket propellants,  especially if you want to make a suborbital flight to another site every month or so.  That takes tons,  not kilograms,  of propellants. 

How "easy" or "hard" something actually is has a lot more to do with what quantity-rate ballpark you are playing in,  and a whole lot less with exactly what scientific principle you choose to employ. 

GW


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#24 2014-01-09 22:20:59

SpaceNut
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Re: Site selection

Agreed chamber size is import to a known rate and to the quantity that can be gotten from what is there for sample intake rate.

The spectrometer map is contained in this document http://solarsystem.nasa.gov/educ/docs/D … Slides.pdf

Here is what Nasa thinks for how to get the water from the soil.... http://www.lpi.usra.edu/publications/re … /csm01.pdf energy levels are way to high....

Here is a recent water quantity to sample size amount Mars soil analysis reveals surprising amount of water

A scoop of fine-grained sand collected by the rover shortly after its August 2012 touchdown showed the soil contains about 2 percent of water by weight. "If you take a cubic foot of that soil you can basically get two pints of water out it," she said. "The soil on the surface is really a little like a sponge for sucking stuff out of the atmosphere." The water was found by heating a tiny bit of soil to 1,535 degrees Fahrenheit (835 degrees Celsius) inside Curiosity`s chemistry laboratory and analyzing the resulting gas releases.

There seems to have been no other tests done since.

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#25 2014-01-10 12:28:13

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,825
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Re: Site selection

So,  some sort of solar-powered microwave oven rig can cook water out of fairly-saturated soils.  Interesting.  I'd guess any explorers/settlers ought to take a bunch of these with them. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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