Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-crg!nike!ucbcad!ucbvax!jade!tart15!c60a-2jm From: c60a-2jm@tart15.BERKELEY.EDU (Adam J. Richter;260E;;) Newsgroups: sci.space Subject: Re: Powersats Message-ID: <1577@jade.BERKELEY.EDU> Date: Sun, 2-Nov-86 06:18:15 EST Article-I.D.: jade.1577 Posted: Sun Nov 2 06:18:15 1986 Date-Received: Tue, 4-Nov-86 04:38:38 EST References: <531179395.amon@h.cs.cmu.edu> <1575@jade.BERKELEY.EDU> <1007@husc2.UUCP> Sender: usenet@jade.BERKELEY.EDU Reply-To: c60a-2jm@tart15.BERKELEY.EDU (Adam J. Richter) Organization: University of California, Berkeley Lines: 40 In article <1007@husc2.UUCP> chiaraviglio@husc2.UUCP (lucius) writes: >In article <1575@jade.BERKELEY.EDU>, c60a-2jm@tart23.BERKELEY.EDU (Adam J. Richter;260E;;) writes: >[Reference to Scientific American article, and explanation of how >phase-conjugate mirrors work, deleted.] >> Small guide beam --> LEO powersat. ^^^ >> LEO powersat --> LOTS OF ENERGY focused almost ^^^ >> perfectly back down the "guide beam." >[ . . .from an amplifying phase-conjugate mirror.] > > Problem is, a powersat in geostationary orbit will be so far away that ^^^^^^^^^^^^^ >in the time it takes for your guide beam to get to the satellite, and the >power beam to get back, the atmospheric distortions recorded by your guide >beam will have changed enough to botch it up. This is not a problem over >short distances -- turbulence can't do much in a few nanoseconds or >microseconds -- but the round-trip time (at lightspeed) to a satellite in >geostationary orbit is something like 0.3(?) second, enough time to mess >things up. Yes, that had occurred to me, which is why I was specific to say an LEO station. Such a station would have a number of receiving points on the ground. Sorry for not being clearer about that point. Alternatively, one could have one GEO powersat and one fixed receiving point on the ground, where the powersat excites an amplifying phase-conjugate mirror that is flying by at LEO. This model has a number of LEO "mirrors" being energized from above, or allows for service during part of the day. It also becomes more practicle as more powersats along different points of the "mirror" orbits come on line. + + + Adam + + + Adam J. Richter ...ucbvax!miro!richter 2504 College Avenue \ richter@miro.berkeley.edu Berkeley, CA 94704 >= May change soon (415)459-9672 /