Rogers
08-15-2007, 12:30 AM
With recent papers and reports further strengthening the scientific concensus on global warming and suggesting that it may be about to worsen very soon, a possible drastic solution may have emerged in the form of miniature satellites.
Space sunshade might be feasible in global warming emergency
The plan would be to launch a constellation of trillions of small free-flying spacecraft a million miles above Earth into an orbit aligned with the sun, called the L-1 orbit.
The spacecraft would form a long, cylindrical cloud with a diameter about half that of Earth, and about 10 times longer. About 10 percent of the sunlight passing through the 60,000-mile length of the cloud, pointing lengthwise between the Earth and the sun, would be diverted away from our planet. The effect would be to uniformly reduce sunlight by about 2 percent over the entire planet, enough to balance the heating of a doubling of atmospheric carbon dioxide in Earth's atmosphere.
The lightweight flyers designed by Angel would be made of a transparent film pierced with small holes. Each flyer would be two feet in diameter, 1/5000 of an inch thick and weigh about a gram, the same as a large butterfly. It would use "MEMS" technology mirrors as tiny sails that tilt to hold the flyers position in the orbiting constellation. The flyer's transparency and steering mechanism prevent it from being blown away by radiation pressure. Radiation pressure is the pressure from the sun's light itself.
Once propelled beyond Earth's atmosphere and gravity with the with an electromagnetic launcher, the flyer stacks would be steered to L-1 orbit by solar-powered ion propulsion, a new method proven in space by the European Space Agency's SMART-1 moon orbiter and NASA's Deep Space 1 probe.
"The concept builds on existing technologies," Angel said. "It seems feasible that it could be developed and deployed in about 25 years at a cost of a few trillion dollars. With care, the solar shade should last about 50 years. So the average cost is about $100 billion a year, or about two-tenths of one percent of the global domestic product."
He added, "The sunshade is no substitute developing renewable energy, the only permanent solution. A similar massive level of technological innovation and financial investment could ensure that.
"But if the planet gets into an abrupt climate crisis that can only be fixed by cooling, it would be good to be ready with some shading solutions that have been worked out”.
http://www.eurekalert.org/pub_releases/2006-11/uoa-ssm110306.php
Space sunshade
http://en.wikipedia.org/wiki/Sunshade
In pictures: Global sunshade
http://news.bbc.co.uk/1/shared/spl/hi/picture_gallery/07/programmes_global_sunshade/html/1.stm
Space sunshade might be feasible in global warming emergency
The plan would be to launch a constellation of trillions of small free-flying spacecraft a million miles above Earth into an orbit aligned with the sun, called the L-1 orbit.
The spacecraft would form a long, cylindrical cloud with a diameter about half that of Earth, and about 10 times longer. About 10 percent of the sunlight passing through the 60,000-mile length of the cloud, pointing lengthwise between the Earth and the sun, would be diverted away from our planet. The effect would be to uniformly reduce sunlight by about 2 percent over the entire planet, enough to balance the heating of a doubling of atmospheric carbon dioxide in Earth's atmosphere.
The lightweight flyers designed by Angel would be made of a transparent film pierced with small holes. Each flyer would be two feet in diameter, 1/5000 of an inch thick and weigh about a gram, the same as a large butterfly. It would use "MEMS" technology mirrors as tiny sails that tilt to hold the flyers position in the orbiting constellation. The flyer's transparency and steering mechanism prevent it from being blown away by radiation pressure. Radiation pressure is the pressure from the sun's light itself.
Once propelled beyond Earth's atmosphere and gravity with the with an electromagnetic launcher, the flyer stacks would be steered to L-1 orbit by solar-powered ion propulsion, a new method proven in space by the European Space Agency's SMART-1 moon orbiter and NASA's Deep Space 1 probe.
"The concept builds on existing technologies," Angel said. "It seems feasible that it could be developed and deployed in about 25 years at a cost of a few trillion dollars. With care, the solar shade should last about 50 years. So the average cost is about $100 billion a year, or about two-tenths of one percent of the global domestic product."
He added, "The sunshade is no substitute developing renewable energy, the only permanent solution. A similar massive level of technological innovation and financial investment could ensure that.
"But if the planet gets into an abrupt climate crisis that can only be fixed by cooling, it would be good to be ready with some shading solutions that have been worked out”.
http://www.eurekalert.org/pub_releases/2006-11/uoa-ssm110306.php
Space sunshade
http://en.wikipedia.org/wiki/Sunshade
In pictures: Global sunshade
http://news.bbc.co.uk/1/shared/spl/hi/picture_gallery/07/programmes_global_sunshade/html/1.stm