Re: [amsat-bb] Going back to the moon in 2015

[Bruce Bostwick <lihan161051@xxxxxxxxxxxxx>]

Many previous discussions on this thread on this list, some of which 
may be archived.

The condensed version .. Any ham radio payload on the moon will have to 
contend with three major problems:

1) Two weeks of -200 degree cold soak followed by two weeks of sunlit 
side of the payload at +200 and shadow side at -200, barring thermal 
conduction.  Neither is particularly conducive to long term survival of 
electronic equipment.

2) Availability of power for the two weeks or so the package is in the 
lunar night.  There are no batteries in existence that will power a 
transponder payload that long in the dark, and unless someone takes 
some RTG's along we can piggyback on (and justify to other major bill 
paying clients the need to draw however many watts we're taking), this 
is a show stopper because power is the key way to deal with 1) above.

3) The earth isn't totally stationary at one spot in the sky (see 
"libration").  You have two options to deal with this -- either settle 
for a lower gain antenna with a wider beam pattern the earth is always 
in, or add the extra cost, complexity, and reduced reliability of a 
movable antenna that tracks the earth in the sky.  Again, riding on 
someone else's launch may mitigate this somewhat since it may be 
possible to put a secondary dish on their tracking platform.

Now, riding on someone else's launch eliminates some HUGE obstacles, 
such as putting the package intact and functioning on the lunar surface 
in the first place as well as the advantages outlined above, but as 
Heinlein so wisely said years ago, the moon is a harsh mistress .. he 
was NOT kidding around.

On Friday, Sep 10, 2004, at 18:28 US/Central, Patrick Green wrote:

> Any chance of an amateur radio payload on those missions?  Placing
> something on the moon perhaps.  It's fixed position makes it ideal to
> have a decent antenna pointed toward earth.  Just an idea.
>
Heard from a flight instructor:
"The only dumb question is the one you DID NOT ask, resulting in my 
going out and having to identify your bits and pieces in the midst of 
torn and twisted metal."


"Oh yeah? Well, I speak LOOOOOOOUD, and I carry a BEEEEEEEger stick -- 
and I use it too!"  **whop!**   -- Yosemite Sam
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