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Space Sunshade to Reduce Global Warming Wednesday, November 26, 2008 - Janice Karin Home >> Picture Of The Day >> Green Technology   
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| Researchers at the University of Arizona are developing an ambitious space sunshade system that could reduce the sunlight reaching the Earth by 2%, enough to balance the heating effects of the increasing amounts of carbon dioxide in the atmosphere. Composed of trillions of miniature spacecraft, this sunshade would form a cylindrical cloud with half of the diameter of the Earth and a length about ten times longer than that located in an L1 orbit. Anything orbiting at this location remains interposed directly between the Sun and the Earth, allowing the shade to constantly filter the sunlight reaching our planet. | ||||||||||
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Each individual piece of the sunshade would be made from a thin film pierced with holes imprinted onto a one micron thick plate of glass, be a mere two feet in diameter, and weigh only a gram. Microelectromechanical (MEMS) mirrors would act as tiny sails, aiding in positioning and ensuring that the system as a whole filters out the projected levels of sunlight. The L1 orbit is not completely stable, so minor corrections controlled by these mirrors will be necessary to maintain the sunshade over time.
Despite the small size and weight of the individual components, the sunshade as a whole adds up to approximately 20 million tons; placing that much mass in orbit using traditional chemical rockets would be prohibitively expensive, so alternative launch methods are a necessary element of the project as a whole.
Project director Roger Angel proposes to solve the launch problem by using electromagnetic rocket launchers developed at Sandia National Laboratory in Albuquerque, New Mexico. Even with 20 such launchers, it would take ten years of launching stacks of rockets every five minutes to fully deploy the sunshade system. Once launched out of Earth orbit, the stacks of components would be steered to L1 orbit using solar powered ion propulsion, the same electromagnetic propulsion method currently used in several NASA and ESA projects.
Angel estimates such a sunshade system could be ready for deployment in as little as 25 years and that careful manufacturing and materials selection could grant each component a 50 year workable lifetime. The shade would be expensive, but presents a viable method of cooling the Earth's temperature if other attempts to mitigate global warming fail or are not sufficient.
TFOT has reported on other innovative technologies designed to reduce greenhouse gases and global warming, including bacteria that produce hydrogen that can be used as a source of clean power, a new material that can reduce the carbon dioxide emissions from power plants, and yachts that spray salty sea water into the air to increase the reflexivity of clouds so they reflect more sunlight back into space.
More information about the space sunshade can be found on an early press release by the University of Arizona and in a follow-up piece in the school's newspaper, the Daily Wildcat. You can also learn more about the head researcher Roger Angel at his College of Optical Sciences faculty page found here. |
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Just what we need, millions of pieces of junk it the atmosphere that cost billions of dollars, takes a fifth of their shelf life to install and crowds the area around our planet to inhibit space launches and satellites. it would be much faster and cheaper to find an earthborn solution to global warming. There would also be much smaller risk of catasrophic failure. |
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What a load of garbage. How much would this cost, and what better use is there. The first thing we need to do is stabilize population numbers. With India's planned growth (exceeding China) all else becomes of little significance. Then we need more efficient systems. Oh, one more thing - I'd like just one piece of evidence that increased CO2 is increasing temperature - all evidence to date shows that there is no effect from CO2 increases - look at the past 10 years - 5% increased CO2, and decreased temperature. |
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The comments by Ben and R James demonstrate why the human race is doomed. First of all, Ben, the shades will be located in orbit L1, which is A MILLION MILES away, not 'in the atmosphere' or 'inhibiting space launches'. And R James says that there is 'no effect from CO2 increases'. We can tell its human-caused CO2 measuring the C12 and C14 isotopes (natural CO2 is different). I burn up when I see these blogs, and I think our grandkids will too - literally. They should have their comments put in a time capsule. Better yet, separate the deniers of Global Warming from those who are working to prevent it, like the author. The descendants of the deniers should be forced to live on this soon-to-be burnt out planet, while those who worked to prevent it should be allowed to live in space colonies. Yes, deploying this system will be costly, but can you tell me how much it will cost to relocate NYC, LA, SF, Miami, Shanghai, HK, Mumbai, etc. when the icecaps melt and they are flooded!!? |
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Scorpion - so tell us how measurement of C12 and C14 proves that increased CO2 causes global warming. Note that I haven't questioned that human activity is contributing to the increased CO2 level. Science tells us that increased CO2 has a logrithmic effect on temperature increase, and that we have already experienced most of this at current levels. As I said before, 5% CO2 increase, yet temperature decreasing. It makes you wonder. Sea levels are rising - they've been doing this for the past 20,000 years, though slower in recent times. I guess it was those big power stations they built 20,000 years ago. Sorry to "burn you up", but still waiting for some science to back up the CO2/heating hypothesis. |
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Scorpion is partly correct though ... the human race is doomed because of the stupidity of such research and comments like his. C12/C14 ratios show that just 2% of the tiny amount of CO2 in the atmosphere derives from fossil fuels. There is no evidence whatsoever that man's CO2 is causing global warming ... and ooops, the globe has been cooling for the past decade anyway ! |
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Let\'s see: 20 million tons mass into Lagrange orbit, launch problem solved by using \'electromagnetic rocket launchers\', (!?) and \'it would take ten years of launching stacks (?) of rockets every five minutes to fully deploy the sunshade system.\' Which then might last 50 years, or forever. Yep, should be feasible. But apart from needing to break every launch record by at least 3 orders of magnitude (there have been in the order of 1,000 launches since Sputnik in 1957, say 10 tons payload per launch, that\'s 10,000 tons; short of the target payload by a factor of 2,000.) But that\'s not the main problem. Some time in the next 1,000 years the planet is highly likely to start cooling (assuming anthropogenic CO2 is the source of the warming problem) as we run out of fossil fuel to burn and the CO2 concentration in the air falls in turn. So if all the shades stay up there, how do we get rid of them if we have to, whenever we have to? |
