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Re: NASA's American Student Moon Orbiter...



The gain increase for the antenna would be deltaG = (12/4)^2 = 9, or 
in dB = 10Log(9) = 9.5 dB.  You get this gain in Tx and again in Rx 
so the total gain = 19 dB.  So this means that the spacecraft will 
need to be 32-19 = 13 dB stronger than AO-40.  So perhaps the S/C 
antenna would be larger and maybe the Tx higher power?

Ed - KL7UW

At 08:16 PM 7/2/2008, w7lrd@comcast.net wrote:
>How would my 12 foot paraclips work for this exercise?
>73 Bob W7LRD
>
>--
>"if this were easy, everyone would be doing it"
>
>-------------- Original message --------------
>From: "Andrew Glasbrenner" <glasbrenner@mindspring.com>
>
> > The moon is roughly 360,000 to 400,000 km away. By comparison, AO-40 had a
> > apogee of about 60,000km. At 2.4Ghz, that's about 16db difference 
> each way.
> > Put AO-40 at the moon, and if I'm doing this right, you'd need about 32
> > times the ground station antenna both coming and going to get 
> with a few db.
> > I'm gonna need a bigger rotor for sure! I'm sure smarter folks 
> will check my
> > math....
> >
> > 73, Drew KO4MA
> >
> > ----- Original Message -----
> > From: "Joe"
> > To: "Andrew Glasbrenner"
> > Cc: "Trevor" ; "AMSAT BB"
> > Sent: Wednesday, July 02, 2008 6:05 PM
> > Subject: Re: [amsat-bb] Re: NASA's American Student Moon Orbiter...
> >
> >
> > > what would a sample average link budget be?
> > >
> > > Andrew Glasbrenner wrote:
> > >
> > >>As far as I can recall we are pursuing both Eagle and the P4 opportunity
> > >>equally, concentrating on common elements until the details are ironed
> > >>out. Neither has been identified as a primary or secondary objective.
> > >>
> > >>I agree a package on a lunar orbiter would be neat, but also that it is
> > >>not the best use of what volunteers we have. We need more folks 
> to step up
> > >>to do things, AND we need to make better use of them when they do.
> > >>
> > >>73, Drew KO4MA
> > >>
> > >>----- Original Message -----
> > >>From: "Trevor"
> > >>To: "AMSAT BB"
> > >>Sent: Wednesday, July 02, 2008 4:53 PM
> > >>Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
> > >>
> > >>
> > >>
> > >>>--- On Wed, 2/7/08, Dave hartzell wrote:
> > >>>
> > >>>>http://www.spaceref.com/news/viewpr.html?pid=25839
> > >>>>http://asmo.arc.nasa.gov/
> > >>>>
> > >>>>Wouldn't it be fun to have a transponder on this! ;-)
> > >>>>
> > >>>Fun yes, but dare I say it, a waste of precious Volunteer resources.
> > >>>
> > >>>All lunar orbits are inherently unstable and will impact after a couple
> > >>>of years. The link budget requirements would not attract a mass user
> > >>>base.
> > >>>
> > >>>I suspect the number of Technically Capable volunteers is already being
> > >>>thinly stretched in trying to provide both the primary 
> objective Phase-IV
> > >>>Lite (funded by Federal Government dollars) and the secondary objective
> > >>>the Eagle HEO.
> > >>>
> > >>>73 Trevor M5AKA
> > >>>
> > >>>
> > >>>
> > >>> __________________________________________________________
> > >>>Not happy with your email address?.
> > >>>Get the one you really want - millions of new email addresses available
> > >>>now at Yahoo! http://uk.docs.yahoo.com/ymail/new.html
> > >>>
> > >>>_______________________________________________
> > >>>Sent via AMSAT-BB@amsat.org. Opinions expressed are those of 
> the author.
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> > >>
> > >>_______________________________________________
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> > >>
> > >>
> > >>
> > >>
> >
> > _______________________________________________
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>_______________________________________________
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