Emergency Funding

Energy systems need not also be solar. You can use
nuclear fuel on the moon just as easily as solar. If protestors allow you to launch. I don't think a full-up radio telescope could be powered by the kind of radio isotope generator which powered Cassini (and even that attracted a lot of protest). I think it's going to need a full-up nuclear reactor. I know there's a NASA push in this direction, but it may be a non-starter, politically (especially after our second Shuttle disaster). I
would see the fact that the sun is blocked 50% of the
time as an advantage not disadvantage. Then you're not viewing things from the High Frontier perspective. Sure, you can
spend extra on shielding out the Sun for HEO, but your
increasing the costs. Yes, but by how much? The material costs of the shield will be quite small compared to the telescope itself. The construction requirements can be quite lax compared to the telescope itself. If we're talking about optical vs. radio astronomy, the shield can be a sheet of aluminized Mylar stiffened with baling wire.
The delta v I have not crunched but if I remember
correctly, there is not a very significant delta v
between the Moon and HEO. Well, it depends on how you define "significant". Compared to the delta V to just get off the Earth in the first place, it's pretty small (and that's always the problem, isn't it?). TLI injection may actually be smaller than injection to and circularization at HEO, but don't forget we have to add in braking thrust for capture into LLO, descent, and soft-landing.
I am not assuming we are in an era with routine
access. A lunar radio observatory can be done with
today's technologies and infrastructure. All that is
needed is a couple of relay satellites and then you
can add to the interferometer on the far side as you
see fit too. I guess we're envisioning different things. I was thinking in terms of an Arecibo-class radio telescope. Its more a matter of cost for this point. I don't
have figures but with the moon you get the shielding
for free whereas in HEO you have to add it. The
additional weight of the shield will also raise launch
costs. But again, by how much? What's the comparison between the delta with and without shielding, and the delta between the two delta-Vs involved? Can a millimeter of aluminum shield out radio waves, and if so, what more would be required for the baffle?
> Who says wires have to be "laid"?
>
Don't have to, but can help reduce costs. How so?
Also, if you wish to keep this off a moon/planet, I
would also ask why stay in HEO? Wouldn't it be better
someplace quieter like an Earth-Sun lagrange point? I'd say the only advantage of HEO over an Earth-Sun Lagrange point is less delta-V from Earth, and considerably shorter flight time. Just getting the dish outside the shadow of the Earth for most of its orbit would confer advantages.
To be totally fair, the only thing I have not heard
addressed by these guys that I still have a problem
with is moonquakes. I have not see this adequately
addressed and hopefully next time I attend one of
their lectures that talks about this topic, I'll be
able to ask them. My understanding is that the moon is sufficiently quiet that this isn't really an issue.
Regards, Mike Combs