Date: Tue, 1 Dec 92 05:11:54 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #480 To: Space Digest Readers Precedence: bulk Space Digest Tue, 1 Dec 92 Volume 15 : Issue 480 Today's Topics: Galileo HGA: Hypothesis Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 1 Dec 1992 05:11:06 GMT From: James Ashton Subject: Galileo HGA: Hypothesis Newsgroups: sci.space In article , henry@zoo.toronto.edu (Henry Spencer) writes: > In article <1992Nov20.000916.4853@sfu.ca> palmer@sfu.ca (Leigh Palmer) writes: > >Another idea: Put a really large radiotelescope in Earth orbit and hook it to > >the Deep Space Network... > > There really is very little advantage to doing this in orbit. Lighter > construction, yes, but much higher costs and no maintenance access. > With the current state of space transportation, you're better off building > it on Earth. Of course in the short term this is true since all those plans to create girders from large rolls of very thin sheet metal have not advanced far. Surely though if people are contemplating multiple square kilometre solar arrays for the future, a kilometre class radio telescope shouldn't be far behind. Rigidity requirements would be much more difficult to meet. You'd need a bunch of active devices to try and hold it in shape and damp vibrations. Slew rates would be long and the solar wind a nuisance. Signal strength would be huge but trying interferometry would be a challenge due to velocity uncertainty of position. ______________________________________________________________________________ James Ashton System Administrator Department of Systems Engineering Voice +61 6 249 0681 Research School of Physical Sciences and Engineering FAX +61 6 249 2698 Australian National University Email James.Ashton@syseng.anu.edu.au GPO Box 4 Canberra ACT 2601 Australia ------------------------------ End of Space Digest Volume 15 : Issue 480 ------------------------------