Quote:
Originally Posted by Van Rijn
Okay, here's the relevant text (and I'm skipping some bits) from New Earths, page 212:
"If we wish to remove 98% of the mass of the Venusian atmosphere in a reasonable time, say, 100 years, we must haul up a mass 10 quintillion tons, or 300,000 tons per second. Compare that to the flow along the Amazon river . . . 10,000 tons per second. The largest machines built which handle flowing water . . . handle 400 tons per second.
Or look at it from an energy requirement: hauling the mass of gas 100 km high, and then accelerating it by 20 km per second requires about 1025 ergs over a 100-year period. That's all the sunlight falling over the same period on an area of 10,000 square km assuming 100% efficiency . . .Throw in a factor of 10 for engineering reality, and the air scoopers must have an area of . . . three times the total area of Venus."
He suggests giant ramscoops connected by elevator/cable to hardware higher up. The ramscoop collects air, compresses or liquifies it, ships it by tanks up the elevator, where it is accelerated away from the planet. There are a number of design issues with these scoopers.  |
I wonder...
Would it take more or less energy than this to build a sunshade, freeze out the atmosphere, and
then transfer it to orbit or beyond? After all, if you are already talking about building a planet-sized solar collector, a simple shade would be easier, and you wouldn't have any friction/wind resistance or weather conditions to worry about, plus the stuff would be easier to move.
The excess gasses could be stored frozen in some convenient orbit behind a permanent sunshield, ready to transfer its contents wherever needed.