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Re: Repeators in Space

Hello Steve.

Happy Holidays.

Since Radio waves travel at the speed of light there really is no way to 
make them go faster because current scientific theory is that nothing can go 
faster then the speed of light.  Now there is some interesting physics 
theory being worked on which might "change" that but at least for our 
science and certianly for our technology thats one of the things that we are 
stuck with.

But "repeaters" or actually "transponders" at various positions in the solar 
system do have value for another reason in that they allow probes and other 
devices (like folks in space suits) to have very low powered radios and 
still remain in touch at very high data rates.  An example of this was the 
Galileo probe.  As weakened as the signal from the orbiter was because of 
its antenna failure I dont believe that communications with the entry probe 
would have been possible Period without the relay ability of the orbiter.

One of the "interesting" ideas for Mars exploration is to put a very large 
satellite in Mars orbit to act much like our geosynch sats do and relay data 
to and from very small probes put a LOT of places on the surface and in 
things like ballons.

My take (for what its worth which is not a lot...grin) is that for the 
foreseable future practical amateur radio "space stations" are going to be 
limited to Earth orbit and perhaps one day on the surface of the Moon tha 
faces the earth.  I dont put much value in sending an amateur payload or 
satllite to say Mars.  The data rates with practical antennas are extremly 
low and the time delay makes a two way transponder almost valuless.  But a 
person taking an amateur station to the Moon or Mars or the NEA or something 
lke that would be "entertaining".

Happy Holidays.


>From: "Steve Howland" <showland9@home.com>
>To: "AMSAT" <amsat-bb@AMSAT.Org>
>Subject: [amsat-bb] Repeators in Space
>Date: Mon, 24 Dec 2001 04:28:16 -0500
>Hope to get some comment going about this , but I have been wondering : how
>long did it take a signal to reach the moon from earth or vice versa during
>the Apollo missions ?  As well, how long does it take a signal to reach our
>Mars probes and landers that we have had ?  Do you think it might be
>possible in future missions to place machines in space that would act as
>repeaters between distant places so that we might cut or eliminate the time
>that it takes for a signal to reach earth ?  From listening to Sputnik 41 ,
>I understand that there were amazing things that could be done with just 
>miliwatts while it was in our orbit.  Just think what we might do with such
>a "space buoy " like a 30 or 50 watt-er placed between us and some distant
>Every dream has to be born some place.  These are the thoughts that lead to
>invention, don't you think ?
>     73' and Merry Christmas
>      de ' KF4FQT
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Robert Oler WB5MZO Houston TX

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