Xref: utzoo sci.astro:13859 sci.space:31797 sci.engr:1393 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!zaphod.mps.ohio-state.edu!mips!cs.uoregon.edu!ogicse!sequent!muncher.sequent.com!szabo From: szabo@sequent.com Newsgroups: sci.astro,sci.space,sci.engr Subject: Re: Platinum-group metal concentrations in earth-crossing objects Message-ID: <1991Jun17.021943.6721@sequent.com> Date: 17 Jun 91 02:19:43 GMT References: <1991Jun16.000359.10311@world.std.com> <1991Jun16.024747.28781@sequent.com> Sender: news@sequent.com (News on Muncher) Organization: Sequent Computer Systems, Inc. Lines: 26 In article rockwell@socrates.umd.edu (Raul Rockwell) writes: >Why process in Earth orbit? Seems to me that you could do quite a >lot, in terms of smelting, or whatever, by processing during the >transfer orbit. Sure, it would take a few years, but so what? Two problems: lifting the heavy processing equipment out to the asteroid, and the round-trip light time for teleoperation. On the other hand, capturing volatiles and raw regolith into Earth orbit will take fairly little equipment and energy, if Earth gravity assist and/or slow aerobraking are used. See previous postings in sci.space for the safety issues involved (a crude summary is that gravity assist and slow aerobraking of small amounts of regolith and ice are fine; fast aerobraking and large solid pieces can be dangerous). Once we have the volatiles and asteroid materials in Earth orbit, equipment can be built and launched from Earth to process the materials into the final products (fuel, heat sinks, shielding, Pt-group metals, new alloys, semiconductors, solar power satellites, etc.). -- Nick Szabo szabo@sequent.com Embrace Change... Keep the Values... Hold Dear the Laughter... These views are my own, and do not represent any organization.