archiv~1.txt: Re: SETI Moon Orbit? Nahhh...

Re: SETI Moon Orbit? Nahhh...

David Woolley ( david@djwhome.demon.co.uk )
Wed, 3 Mar 1999 08:32:27 +0000 (GMT)

> >Several pentium 2 or 3 motherboards to do real-time processing,

Would almost certainly suffer from multiple upsets due to radiation,
and be destroyed by that radiation in a relatively short time - I believe
the preference is for CMOS and conservative designs.

Processor would destroy itself by overheating or shut down because of
lack of effective local cooling (these devices are air cooled).

> >analysis, and storage perhaps usinging a specialized version of PAOOS.

PAOOS is nearly all about user interface, as best I can tell; you would
have to launch a user with it for it to be much use. (Please try to
avoid confusing a product with the basic principles.)

> >A 10 GB hard disk for short term storage. (routine information - low
> >priority hits, etc)

Wouldn't survive the launch G forces, and even if it did, the heads would
crash because of the lack of air and the bearings might well seize as
lubricants evaporated.

> >
> >A DDS-4 20 GB DAT for longer term storage (high priority hits, repeated
> >observations, etc)

Loss of lubricants, static build up.

> >A small dish antenna for data collection (remember since observations
> >would be made on the lunar farside and thus blocked from earthbound noise

My understanding is that local interference is a nuisance factor on
the hydrogen line, not the limiting factor. Obviously you would be able
to observe frequencies used for man made signals, but with less range than
a reasonable telescope on the ground at around 1.42GHz.

All serious far side telescope proposals I have seen put the antenna on
the moon's surface and use a large one.

> >
> >Cost:
> >
> >I'd imagine the total cost of such a craft and mission (exluding launch
> >costs) would be around $500,000 US or about twice the cost of SETI@Home.

Launch cost would be several orders of magnitude greater than this, and
it would probably need a dedicated launch vehicle as very few scientific
lunar satellites are launched and no-one is going to admit to military
ones, if they exist.

$500,000 is less than 5 man years. I assume that SETI@Home has a
similar proportion of its labour supplied free.