Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site mordor.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!mcnc!decvax!genrad!panda!talcott!harvard!seismo!ut-sally!mordor!@S1-A.ARPA,@MIT-MC.ARPA:DIETZ@RUTGERS.ARPA From: @S1-A.ARPA,@MIT-MC.ARPA:DIETZ@RUTGERS.ARPA Newsgroups: net.space Subject: Shoot the Moon Message-ID: <2378@mordor.UUCP> Date: Sat, 22-Jun-85 22:09:22 EDT Article-I.D.: mordor.2378 Posted: Sat Jun 22 22:09:22 1985 Date-Received: Sun, 30-Jun-85 00:35:56 EDT Sender: daemon@mordor.UUCP Lines: 53 From: DIETZ@RUTGERS.ARPA The Apollo missions revealed one serious obstacle to lunar colonization and exploitation: an almost total lack of volatile elements in lunar rock. There is very little carbon, nitrogen, hydrogen or halogens; even lead is seriously depleted. This is now thought to have been a consequence of the formation of the moon from debris blasted from the earth by a collision with a mars-size body early in the history of the solar system. A volatile elements were disbursed before the cloud could condense into dust particles. At any rate, this is a serious obstacle to any would-be colonist. Hydrogen is necessary for water, food and rocket fuel. Carbon and nitrogen are needed for food and plastics. Fluorine is vital in the chemical processing of lunar materials. Delivering this material to the moon by rocket is expensive, even with advanced orbital transfer vehicles. Delivering it to near lunar space is somewaht cheaper, since you don't have to ferry it down, but still expensive. I propose a very cheap method for shipping bulk supplies to the lunar surface. The idea is to build a large electromagnetic accelerator on the Earth's surface. Payloads consisting of ~100 kg of plastic are launched at the moon. These payloads hit the moon at several km/sec, completely destroying them; however, the target area is covered with a layer of fine soil to absorb the kinetic energy. Periodically the soil is sifted to remove debris, which is then refined to extract needed volatiles. Assuming the accelerator can be built sufficiently cheaply, the main problem is guidance. Travelling up through the atmosphere, the payloads will ablate and be pushed about by winds. Their velocities will have a significant random component. Some sort of active guidance will be needed to make course corrections. I suggest placing in each payload package a small microwave transceiver, some control electronics, a battery, and some low power thruster rockets. The position of the payload is determined by triangulation from large satellites placed in earth orbit, at the L4 and L5 points, and somewhere out of Earth/Moon system plane. Course correction calculations are made at a central computing facility on Earth and relayed back to the payloads. All the elements I mentioned above can be delivered by this mechanism. Hydrogen and carbon are delivered as polyethylene. Fluorine is delivered as Teflon. Nitrogen can be delivered as Nylon. The guidance and control package will be destroyed on impact, but perhaps some useful metal can be extracted. A rough guess of cost can be made by calculating energy cost (~$3/kg at 30% launcher efficiency and $.05/KWHr) and capital costs (at $5 billion dollars spread over five years at 100,000 tonnes/year, about $10/kg). This ignores guidance package costs, which might add another $10/kg (if the package costs ~$1000, probably an overestimate). -------