Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!srhqla!denwa!stb!charles From: charles@stb.info.com (Charles (from bbs)) Newsgroups: sci.space Subject: Mining El Dorado Message-ID: <1991Jun16.195153.9959@stb.info.com> Date: 16 Jun 91 19:51:53 GMT Organization: The Serial Tree BBS, +1 213 397 3137 Lines: 62 How do we mine the El Dorado asteroid ? Is it one big stainless steel nugget, or is it differentiated ? Either way, I propose blasting it to pieces using high explosives. If it is a homogeneous stainless steel nugget I would drill a hole right to the center and insert a small nuclear device. If it is differentiated, conventional explosives might suffice. Nuclear gives more bang per pound, so better than chemical and takes less propellant to send it to El Dorado. We do not want lots of fragments flying everywhere, all we need is to create a powerful shock wave to disrupt the asteroid structure. The shock should be small enough that gravity will continue to hold the pieces together. We could literally surround the asteroid with a safety net to ensure most of it is retained. Once shocked the pieces can be individually transported or processed by a robot smelter. If it is well differentiated it might be possible to visually separate out nuggetts of rare metals, and discard the silicates and iron. A weak acid could dissolve reactive metals ( alkali earth and alkali metals and iron ) and heavier metals like Gold and Platinum would be beneficiated. If desired the acid solution could be electrolysed with low energy to recover the lighter metals. Beneficiating by weight might be possible, would have to spin the nuggetts in a centrifuge to find out how dense they are. Each nugget could also be scanned by alpha particle back scattering or other radio-spectroscopy means, and then sorted into valuable and less valuable bins. Probably cheaper than electrolysis too. Most efficient might be to use minimum size ( ie critical mass only ) nuclear charges, and progressively shock parts of El Dorado, that allows more margin for error in case we guess wrong about the quantity of shock needed - do not want to over do it ! Would need rather a lot of diamond drills if it is steel, maybe somebody could design a laser cutting torch so we can burn our way in. How about a deliberate nuclear pile meltdown on the surface, the hot pile melts to the center via gravity - al la China Syndrome. An advantage of a single blast dead center would be that the surface structure would be least affected, so it might be possible to the centre, and leaving a large hollow structure which could be turned into a human habitat. I like that better than progressively blasting it completely to pieces from the outside. Residual radiation might be a problem for future colonists, I wonder what the half-life would be. In the immediate term it would be interesting to send a probe to El Dorado, to see if it is differentiated or homogoneous. El Dorado is probably spinning, so the blast could be timed such that the exhaust coming out of the drill hole would cause a reaction which would tend to propel the asteroid towards the Earth a little. We do not have controlled fusion, but maybe a large thermonuclear device could be designed as a shaped charge. After the initial fission explosion and hollowing out some of the interior, the thermonuclear shaped charge could be inserted into the interior of El Dorado, and the drill hole widened. The blast would then be mostly directed out through the vent hole, creating a more substantial thrust reaction, which could maybe manouver El Dorado within a few million miles of Earth. This would be most useful if the blast could be done at perihelion, thus lowering the aphelion, making collection of the asteroid pieces much cheaper. Perhaps the nuclear shocking and thrusting could be a government program. Then collection and benefaction of the pieces could be by private prospectors. * Origin: Ventura Co NSS 805-649-5314 STS final approach (1:206/2403.0)