🚀 go-pugleaf

In article <1022@thumper.bellcore.com> karn@thumper.bellcore.com (Phil R. Karn) writes:
>> ... The dark far side of the
>> : moon..." being a good place to conduct " ...sensitive radio astronomy...
>> : without interference from terrestrial signals."
>
>Yes, it's a great idea. In fact, it's already been done. Only it was an
>unmanned probe in lunar orbit instead of a manned base on the surface. 
>The spacecraft recorded its observations during the time it was shielded
>from earth, and it relayed them back down when earth was visible.
>
>I really wish people would stop clutching at straws, looking for every
>possible application of their pet man-in-space project when many (if not
>most) of the tasks can be done far more cheaply and effectively with
                                                     ^^^^^^^^^^^
Are you sure about this??? -------------------------------|
It seems to me that long term observations of some objects would be
easier to carry out on the moon, as opposed to a satellite.  (Which
would be orbiting the moon....at times having the moon itself eclipse
the very object under observation!)

>unmanned spacecraft. In the case of lunar-shielded radio astronomy,
>lunar orbit makes a lot more sense than the lunar surface for several
>very good reasons:
>
>1. You need communications channels back to earth. A radio telescope on
>the far side of the moon would need relay satellites in lunar orbit for
>this purpose. These satellites would themselves have to transmit within
>view of the far side of the moon, possibly polluting the very spectrum
>you spent so much to view in a pristine state. On the other hand, a
>telescope in lunar orbit can provide its own store-and-forward relay. It
>need not transmit anything at all while it is actually observing.

Come on!  This is a weak argument.  For one thing, the same store and
forward technology could just as easily be used for the moon to earth
relay satellites. 

>2. You need power. This is much easier to obtain in orbit, since solar
>panels will be illuminated for roughly half of each orbit. On the
>surface, you will almost certainly need nuclear power sources to carry

This may be true...but what about running cables to the other side of the
moon to carry electricity while the telescope is in the lunar night.
Several solar power arrays would keep the telescope powered continuously.
Superconducting cables would help...even to the point of eliminating
the need for a relay sat. in orbit.  Just place your communications
antenna on the earth-facing side of the moon!

>you through the long 2-week lunar night.  Thermal control is also much
>easier in orbit. Of course much of a surface station could be buried to
>help level out the day/night temperature fluctuations, except for the
>antennas -- and these are likely to be very susceptible to severe
>thermal-induced distortions.
> [....]
>
>Phil

Just thought I`d say something. The radio telescope on the moon is
a great idea.  Even if people use it as an excuse for getting men &
women in space, so what!  What`s wrong with that?  Isn`t that the goal
we all have...or am I being silly

Let`s explore the possibility of having both oribiting and surface
telecopes.  

Ollie Eisman - N6LTJ
--
SEDS-UNM : Students for the Exploration and Development of Space           
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