Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!decwrl!amdcad!lll-crg!ucdavis!ucbvax!space From: dietz@SLB-DOLL.CSNET (Paul Dietz) Newsgroups: net.space Subject: Re: scuttle the shuttle? Message-ID: <8602071650.AA11720@s1-b.arpa> Date: Fri, 7-Feb-86 09:13:27 EST Article-I.D.: s1-b.8602071650.AA11720 Posted: Fri Feb 7 09:13:27 1986 Date-Received: Tue, 11-Feb-86 04:36:45 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 45 > Why wouldn't LEO EVA expertise transfer to GEO? Because it's hard to keep people in GEO. Teleoperator technology would extend easily, perhaps all the way to the moon. > it's not clear to me that > the large majority of space construction activities must be done in GEO, or > even should be. Maintenance of large structures will take place in GEO. Construction using extraterrestrial materials should be done in high orbit. Very large structures cannot be built in low orbit because of air drag. > Also, while I believe that you are sincere, I have yet to see the > teleoperators of the required complexity. And, further, if you redesign the > product so that robots and/or teleoperators can build them, you're simply > trading the cost of putting people in orbit for the increased cost of > teleoperators and machine design. Further, the costs are not only in > the increased costs of each product, but also in the products that you decide > you can't make because they don't come in snap-together pieces. I don't believe modular design will add more than a fraction to the cost of any product. I'm not suggesting each and every transistor be in a separate box. Launching costs are so high that the redesign cost (or, rather, the cost of making new designs modular) would be insignificant. The current absence of teleoperators of the required complexity is more an indication of lack of demand rather than inherent impossibility. On earth most remotely controlled machines are for observation or bulk manipulation (submersible recovery vehicles, mining machines), not for delicate operations. The rapid advance of electronics, communication technology and robotics tells me that teleoperator technology get cheaper quickly. Rocket technology is evolving slowly, and has much less spinoff potential. > Finally, remember Skylab? I'm damned glad we didn't have a robot > trying to repair *that*; it never would have had any power. Current teleoperators couldn't have repaired Skylab, but the Skylab failure was hardly a typical failure mode. Replacement of defective or burned out electronics, replenishment of expendable fluids and replacement of worn mechanical parts would, I think, account for 90% of maintenance activities in space. There's no sense treating rare cases as typical.