dad@u1100s.UUCP (09/16/83)
Several people have recently posted articles arguing that since commercial aviation is able to move more than 300K people per day, it should be possible to have an out migration from Earth of the same magnitude. One significant problem with this line of reasoning is that the vehicles used to transport commercial aviation passengers one day are still around to transport more passengers the next day. In an out bound migration, the vehicles used to transport the passengers are gone from the system once they are used. (I am talking about the interplanetary vehicles, not the shuttles used to move the passengers to Earth orbit.) I would hate to think what would happen to the Earth's supplies of spaceship building materials (e.g. titanium) after 100 years of sending out thousands of ships each day. Doug Davey Bell Labs ihnp4!u1100s!dad
Heiny.Henr@Parc-Maxc.Arpa@sri-unix.UUCP (09/19/83)
From: Chris Heiny <Heiny.Henr@Parc-Maxc.Arpa> "One significant problem with this line of reasoning is that the vehicles used to transport commercial aviation passengers one day are still around to transport more passengers the next day. In an out bound migration, the vehicles used to transport the passengers are gone from the system once they are used. (I am talking about the interplanetary vehicles, not the shuttles used to move the passengers to Earth orbit.) I would hate to think what would happen to the Earth's supplies of spaceship building materials (e.g. titanium) after 100 years of sending out thousands of ships each day" Detroit has been consuming much more steel to produce autos than it has in it's natural environs for the past 70 years. Perhaps titanium, etc. can be imported to earth. The ships could even be built on the moon, a much more reasonable place to construct them: you wouldn't have to lift them out of earths gravity well. And the ships would also probably be used to make round trips: it is probably more economical to send an partly loaded liner back to earth from the asteroids than to build another and let that one rust. Eventually trade between the colonies and earth would reach a point where vessels would be fully laden each way (as with trade between the New World and Europe). Europe was not denuded of trees and iron during the conquest of the New World. Chris
REM@MIT-MC@sri-unix.UUCP (09/20/83)
From: Robert Elton Maas <REM @ MIT-MC> You are arguing a red herring. Nobody (in hir right mind) would propose building millions of spacecraft on Earth and sending them up once and never bringing them back for reuse, when a shuttle exists as an alternative. The idea is to reuse shuttles many times, like commercial airliners, to transport people in large numbers from Earth to space stations. At that point the people may move into new space habitats which are built in space out of space-found materials, or may be moved to other places in spaceships built again out of space-found materials.