REM%MIT-MC@sri-unix.UUCP (11/13/83)
From: Robert Elton Maas <REM @ MIT-MC> Here's an idea I came up with this morning. If it's new, please let me know so I can file for patent. If it's old, please tell me whether the idea will work, what others have thought about it before, whether there are any plans to implement it. This is an alternative to a ramjet for scooping gasses out of the atmosphere of planets for use in space. Suppose we hang a tube from low-planetary-orbit into the atmosphere of that planet, and attach a scoop at the bottom to collect some gas. Inside the scoop we strip electrons from the atoms by a corona discharge with positive charge. We have a negatively-charged corona discharge up higher to attract the ions and to neutralize their charge and to provide the current return for the other electrode. We thus use an electric current to pump material from the bottom end to the top end of this tube. Unfortunately gravity isn't linear whereas charge mostly is, so if we use a single stage pump we'll have ions just barely starting their trip at the bottom and then encountering more and more net force as they reach te top, reaching relativistic speeds and emitting gamma rays as they strike the top. So what we do is break up the pump into segments short enough that along each segment the force of gravity is close enough to linear that by carefully adjusting the charge-difference along each segment we can avoid relativistic speeds. Alternately we can use the principle of the synchotron (I think that's the right one) which packs the ions into batches, using an alternating current, attracting a batch from above as it approaches a charge point then repelling it from below just after it passes that point, or using alternating magnetic fields to induce a pseudo-electric-field. In any case, with the device set to just barely capture the lightest ions, it'll get mostly Hydrogen, no matter which planet we fetch the gas from. Hydrogen just happens to be one of the elements we need most in space, because it isn't available in moon rocks in any reasonable quantity, so this is a "win". If we use Venus as our supplier, and we increase the charge so lots of different ions can be collected, we'll get lots of carbon dioxide and sulpheric acid in the scoop, supplying Carbon which is also in short supply on the Moon and of great use, and Sulfur. (We can discard most of the Oxygen since we'll be getting it in surplus from the Moon.) Of course this whole device will be powered by the Sun, using the derived electricity both to run the ion pump itself and to forcibly discard Oxygen and other waste as reaction mass to counteract atmospheric drag.