Earth's AirConditioner; NaCl versus aluminum

I need a detailed analysis of which of these two substances serve as the reflector best. Weight is a crucial factor in that something lightweight must be cargo
hauled to the Space Station and released there. What is the weight comparison of NaCl salt crystals compared to aluminum sheets or strips? Aluminum is atomic number 13 and sodium is 11 and chlorine is 17. So which one wins the weight category for cargo hauling??
Salt as the reflector makes more sense when considering entering or leaving the Earth in that you would rather have your spaceship ram into a salt layer rather than a layer of aluminum metal.
And also, Earth is abundant in salt and aluminum but what happens to aluminum as it re-enters Earth atmosphere? Is it turned into a gas and harmful? Salt is not a health hazard but aluminum in vapor form maybe a health hazard.
And the processing of aluminum from mining until final processing costs alot in terms of energy. Whereas harvesting salt is as easy as evaporation of ocean water and collecting the salt crystals. But there maybe some final processing of salt in order to make it reflect well once placed in orbit from the Space Station.
I spoke of earlier of an Oilfilm. A monolayer molecule. Is there a monolayer molecule that can spread out once released by the Spacestation and can reflect Sunlight? Most monolayer molecules I know of are scents and fragrances such as rose scent or perfumes. But, is there a monolayer molecule that spreads out once released by the SpaceStation and has the property of reflecting light from the Sun?
Perhaps a conjunction of materials will be the most ideal. Where you put salt crystals plus some Oilfilm where the salt is embedded in the oilfilm that makes a outer-space structure which we call Earth's AirConditioner.
Archimedes Plutonium, a snipped-for-privacy@hotmail.com whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I am going under the presumption that reflection of sunrays in the upper atmosphere or in outer space is going to be the mode of Air Conditioning Earth. That assumption maybe incorrect in that some other mode is possible such as a material placed in orbit from the SpaceStation that absorbs sunlight and not reflect it. Some black carbon compound or sulfur compound whose advantage over salt is lighter weight and less of a health hazard.
Archimedes Plutonium, a snipped-for-privacy@hotmail.com whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
So far I have 4 contenders to making Earth's First AirConditioner. Either salt crystals or some Oilfilm or some CFC-variant and now perhaps some fiber material such as cotton fibers.
What I do not know is how these materials will react when released by the Space Station in that weightless environment of near zero gravity? Will salt crystals just clump together and not spread out? Will fibers just matt together and not spread out? Will a Oilfilm form droplets instead of spreading out?
Perhaps the sphere formed from the orbit of the Space Station has some scientific name? Anyone know. And the name of the sphere that is the apex of the upper atmosphere? What I am getting at is that perhaps the ideal place to make Earth's AirConditioner and to release the refrigerant be it salt crystals or
fibers or some Oilfilm etc etc is one of these special spherical layers that may or may not be the sphere formed from the orbiting SpaceStation.
These enquires are best suited for a materials scientist who knows the behaviour of materials in various layers of the atmosphere and stretching to the SpaceStation layer.
If it is a fiber that is the ideal refrigerant by reflecting a chosen amount of the Sun's rays, then a fiber would be easier to cargo haul since lighter than salt crystals. And probably not a health hazard as it reenters to Earth's surface.
But can a fiber be made to spread out in one of Earth's upper atmosphere layers?
Perhaps a combination of some of these candidates makes the best refrigerant.
Archimedes Plutonium, a snipped-for-privacy@hotmail.com whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In sci.physics, Archimedes Plutonium
wrote on Tue, 29 Jul 2003 15:08:30 -0500

This sounds even more daft than someone's pseudo-proposal of pumping sea water onto the South Pole and letting it freeze (my computations for that suggest over 10x the power output of California, for starters, to achieve maybe 1 mm/year).
How many metric tonnes of salt per orbit are we talking?
And CFCs into the upper atmosphere is political suicide nowadays. Anyone seriously proposing that will probably be attacked by a rabid horde of slavering environmentalists. :-)

Sphere? More like a curved band. I'd have to look up the maximum latitude, though.
In order to pass over every point of Earth a satellite would have to be in a polar orbit.

There is a gradual thinning out of the atmosphere to a few wisps at some point; it's not a hard boundary.

I'd not want ISS to orbit just above the atmosphere. Too much thrust required to keep it there. It's in a higher orbit than that for a reason.... :-)
There was an experiment -- sorry, can't remember the name offhand -- which stayed up for 5 years or so and was "rescued" about 1 month before it was destined to take that final plunge. Its orbit had decayed quite a bit while it was up there -- all due to atmospheric friction, what little there is up there, and a couple of other factors (such as solar wind).
It's given us valuable input on performance of materials in space over long periods. If we ever do build a Mars shuttle (a fairly stupid idea except for the "gee whiz" factor, as it would require six months of transit time and exposure to hard radiation -- and every moment observable to Earth scientists, which precludes such things as space sex, messy as that might be anyway) and better satellites, we'll have to learn such things.
As for air-conditioning the Earth -- we'd probably be best off deploying a bunch of aluminum or plastic reflectors on the ocean or something on a cloudless day. A *lot* of 'em. :-)
[rest snipped]
--
#191, snipped-for-privacy@earthlink.net
It's still legal to go .sigless.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Why not let volcanic ash cool the earth.
message

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
30 Jul 2003 09:45:31 -0700 al kemist wrote:

Thanks for the physical determinants.
I think salt also has the advantages of exiting and re-entry to Earth with space travel. Witness the latest shuttle disaster of foam insulation causing a hole. Plowing through aluminum sheets or aluminum foil or aluminum strips is going to be more harmful to a spacecraft than is plowing through a film of salt crystals.
Also, I think the energy on the surface of the Earth in order to manufacture enough aluminum to build the EarthAirConditioner is going to zap too much energy whereas salt crystals can be collected from simply putting to work millions of Chinese and Indian laborers in evaporating pools and never spend a single erg of fossil fuel energy or fission energy in obtaining the salt.
What I need to know for sure is: (1) how does salt behave once released from the Space Station (2) how much salt is needed to cool Earth by 1 degree centigrade?
BTW, heard on the news that the Space Station is in threat of discontinuing due to a wrangle between the funding. Funny how this SpaceStation is in threat now but is the backbone and lifeblood for building Earth'sAirConditioner and future generations will look back and probably remember us mostly for one engineering project-- EarthAirConditioner.
Come to think of it, we really have been lazy for the past 200 or 300 years as far as engineering marvels. Of course, building the SpaceStation itself was perhaps the finest engineering in the 20th century. Let us make the EarthAirConditioner the marvel of the 21st century.
Archimedes Plutonium, a snipped-for-privacy@hotmail.com whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You can't possibly be this dumb! No human being could, certainly not one who can spell aluminum. Bad troll! Bad! Down I say!
Pragmatist
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The solution is to slice AP in very thin sections and use him to shade the earth.
Gordon
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 28 Jul 2003 15:33:44 -0500, Archimedes Plutonium

Hi Archie
I would not expect to reply to one of your posts. But this must be the first intentional reply! Are you trying to coool the earth by cutting back on sunlight? putting a big Saturn like ring of salt dust in orbit could scatter the sun, but it would als wreck the night time dark night sky. I would say don't do it near earth. Put a ring around Venus and cool that hot planet down to terraform it.
I would worry that the salt dust or aluminium flakes would blow away in whatever thin winds were up there. So the cloud may not last very long. X X X X X
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Octa Ex wrote:

I've always thought that small gentle adjustments to the average albedo would be the way to go.
When you look at the sort of stuff than can cause major climatic change -- fairly big things like the Deccan Traps or Krakatoa, or moderately big things, like human beings inventing the internal combustion engine and running it full tilt for a couple hundred years -- they don't add up to very much interms of moderate horsepower over a big area.
Thus I'd think we ought to be able to smooth the joint out by, say, covering the Sahara with little silver mirrors that could switch position (under wind power, Iimagine) depening on who we wanted to control that couple million square miles of albedo.
'Course when you start to think about stuff like that, you're thinking of turning the Monsoon on and off, redirecting El Ninjo and La Whatshername, not Ninja(!), and otheise messing with the local weather. You better have a couple of years spare food for a couple of billion people before you try this trick at home.
-dlj.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
David Lloyd-Jones wrote:

You obviously have not done any, or enough math on this. And a simple counterexample proves you wrong. I said cool the Earth by 1 degree Centigrade per year. If you think that covering the Sahara with mirrors, then it would be practical to thrust that energy not into outer space but into electric generators.
So, why has no power company covered the Sahara in mirrors. Answer: not that much energy and certainly not the amount of energy to cool Earth by 1 degree Centigrade per year.
Archimedes Plutonium, a snipped-for-privacy@hotmail.com whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Very interesting!
How could it be adjusted, if the Earth was getting too cool would it be easy to remove a sheet?
How many would be needed and how long would it take to place them in orbit, assuming a blocking of 1% of the Earth's surface was needed?
Cheers, Alastair.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
message

Depends on the mirror array. More below.

For cooling effects, I think the desired position would be not in Earth orbit exactly, but at the "Lagrange point" between the Earth and sun where the Earth's and Sun's gravities cancel. (Something like this is a typical proposal for cooling Venus prior to further terraforming).
Sunlight pressure (and to a less extent, solar wind) would actually require moving the sail away from the exact Lagrange point, so that sunlight pressure was balancing the mirror against the Sun's gravity. You're looking at several pounds of force per square mile of mirror and mirror with millions of square miles.
Anyway, the mirror would need to be huge. I don't know exactly at what rate the umbra and penumbra of planets taper off, but for a mirror several million miles away from the Earth (which is where the above Lagrange point is) to block 1% of sunlight reaching Earth, you're probably looking at an array as big or bigger in diameter than Earth. That isn't exactly a near-future construction project, even using ultra lightweight foil mirrors.
When you wanted to move the mirror array, you could probably have it designed so the individual mirror segments can tilt. That would probably be necessary for stationkeeping in any case - the gravity of other planets would perturb the mirror array away from its "proper" location. By tilting the mirrors, you could reflect sunlight off in a different direction and thus scoot the array sideways, turn it, etc.
A simple solution might be to simply pivot the mirror array so it was edge-on to Earth. Alternately, it could be scooted into a halo orbit around the Lagrange point so its shadow circled Earth, but never touched it.
Mike Miller
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I get it now. It would be orbiting the Sun, inside the Earth's orbit.

Sorry, but it won't do! We need to launch pretty soon, probably this winter. Could we use a set of geostationary mirrors. Would they shade the polar regions as well as the tropics? How many will we need for a 1% reduction in solar flux?
Cheers, Alastair.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
message

Then it isn't feasible. The launch capacity doesn't exist, even if you roped every model rocket motor and chili bean-overloaded Texan into the launch effort. It would take longer than from now to this winter to develop and test the satellites. Given the area needed (see below), you'll need a lot longer just to roll enough aluminum.

Sure, given 3-4 decades and exhaustion of the global economy on the effort.

No. GEO is an equatorial orbit, pretty much.

I figure a band of satellites with 4% of Earth's area between the Earth and sun at any given time would do, so 2 million square miles at any given instant...figure 24 million square miles of mirror area should do the job.
How many satellites do you need? Pick a number of square miles per satellite (I'll let you decide) and divide 24 million by that.
Mike Miller
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Oh well, we will just have to go back to Archies' idea and use a gas. What would be the effect of making all air liners fly at 40,000 feet instead of 30,000 feet. Would their con trails have an effect? That has probably not been considered in the case of terra forming Venus.
Cheers, Alastair.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Alastair McDonald wrote:

This is only sorta true. A satellite in polar orgit with a period of 24 hours will travel in an apparent straight line along a longitude.
So if you want to shade the poles all you need is a ribbon shaped mirror far enough out that all of it has a 24 hour period. Thisis the same distance out as the generally equatorial geostationaries, 29.2K miles or whatever it is. So a mirror roughly 196,000 miles long would do the job nicely.
Go for it: the Hunt brothers will luvya.
-dlj.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike Miller wrote:

Seems to me we'll have vulcanism under control long before we have the massive productivity needed to produce space mirrors on that scale.
"A Krakatoa a day keeps the sunlight away." :-)
Cheers,
-dlj.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Naw. You'd only need about 1 ton of aluminum per square mile, possibly less for the really thin foils. With several hundred million square miles you'd...gee, that IS several years of global aluminum production.

That might be an easier answer. :)
Got any large volcanos and spare nukes?
Mike Miller, Materials Engineer
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike Miller wrote:
whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.