Consider that the US Congress approved Bush's War Funding Bill to
the order of approximately $75 Billion.

Tangoman: I agree with O'Neill's approach, that major space projects
should have benefits on Earth, and space settlements will bootstrap
from there. For $75 billion we could have an SSPS station and a
service colony. Once the benefits and profitability are demonstrated,
more funding, government or private, are likely to follow.
Now that Japan is planning an SSPS program, maybe we could
induce the US energy industry to take a serious look also. With the
energy industry well represented in the White House, maybe this is a
good time for some serious lobbying.

> Consider that the US Congress approved Bush's War Funding Bill to
> the order of approximately $75 Billion.

--- In ssi_list@... "Xenophile"
>
> > Consider that the US Congress approved Bush's War Funding Bill to
> > the order of approximately $75 Billion.
>
> I am considering it... and am NOT saying if that is a good or bad
> thing. I intend to stay on topic. (You listening, folks?)
>
> > What do you think could be built in space with a one time
> > commitment of $75 billion?
>
> Well, if it was absolutely one time, with no follow-up whatsoever,
> then it would be a waste. But I think that you mean "on top of
> whatever is normally spent."
>
> So let's see... $75 billion...
>
> OK, this is what I'm going to do: I have just been made NASA
> Administrator (yeah, right!), and that Congress and the President
> have handed me the moolah with the instructions, "Do something
great
> for America and the World!" (this seems even less likely).
>
> Is this what you had in mind?

okay I'll bite.

> okay I'll bite.
>
> First off, I would not spend it all on getting humans
> into space. Here is a rough breakdown:
>
> 15 bill - Planetary explorer craft (using a host of
> new technologies)

> > 10 bill - Reusable vehicle design
>
> I know that the Shuttles cost about $2 bill apiece when the last one
> rolled out. Do you have any idea how much the R&D was for the
> program?
>
> I hope that this R&D is managed more efficiently than what I've read
> about the Shuttle programs development.

didnt we establish thta it really isnt hardware or fuel that makes up the
great costs for launching? That it was the thousands of personal?

Well, if they gave it to NASA you could get almost 70 X33s for that!

> > 15 bill - Planetary explorer craft (using a host
> of
> > new technologies)
>
> JPL is firing these babies off pretty inexpensively
> these days.
> Right? Would the new tech add a lot to the cost, or
> would you just
> send out 30 different probes?
I am more thinking cassini type scale. Yes JPL has
been making faster, better, cheaper mission but I am
still not sold that a cheap mission to europe or titan
is worth it. I would like to see about 2-4 billion
spent on each mission.

> but then I'm not
> really up on the tech side of CELSS and what still
> needs to be done.
> Can you really spend that much?

> What are Frank Drake's arguments for a lunar radio
> observatory over a HEO
> one? (And bear in mind that even an accomplished
> scientist like Frank Drake
> can still suffer from planetary chauvinism.)
>

- Many elements can be placed in perfectly stable
relative positions; they do not need to continually
monitored and have their positions controlled. True. But the question then becomes: do the operational disadvantages of having to monitor and maintain position outweigh the disadvantages of having half the sky blocked to you, being cut off from solar power 50% of the time, and being more remote from the Earth in terms of delta V?
- Lunar observatory would last virtually forever by
not being limitted by onboard fuel. (though relay
satellite would need to be replaced) If we're operating in an era of routine access to the moon, the refueling of an orbital platform ought to not be too great a burden.
- Basis for future scientific stations. (help build
infrastructure on the moon arguement) This works equally well for building infrastructure in High Earth Orbit. Some of us (I would hope everybody on this list) see great value in such infrastructure.
- There are craters to avoid lunar-surface
interferences (in case of future interference) The shield baffle would be a necessary part of the orbital dish, granted. So again, the issue becomes: Does the advantage of being able to skip the shield outweigh the disadvantages of being on a planetary body?
- stable enough for interferometry (though recent
advanced in formation flying are starting to catch up
to the point where this is becoming less an arguement,
but for now it holds) Good points.
- Sun is blocked half the time. But this is a disadvantage from the point of view of powering the array. On the other hand, an orbital telescope can be blocked from the sun all of the time with nothing more than a sheet of aluminized Mylar.
- long integration time (slow rotation) That's an advantage over the Earth, not over HEO. An orbital array could have zero rotation, allowing essentially unlimited integration time.
- antenna elements wires can be laid directly on
regolith. Who says wires have to be "laid"?

--- In ssi_list@... "Combs, Mike"

--- In ssi_list@... "Combs, Mike"
>
> - Many elements can be placed in perfectly stable
> relative positions; they do not need to continually
> monitored and have their positions controlled.
>

>
> - Many elements can be placed in perfectly stable
> relative positions; they do not need to continually
> monitored and have their positions controlled.
>
> True. But the question then becomes: do the
> operational disadvantages of
> having to monitor and maintain position outweigh the
> disadvantages of having
> half the sky blocked to you, being cut off from
> solar power 50% of the time,
> and being more remote from the Earth in terms of
> delta V?
>
it only matters when making very fine measurements.
When going for such things as millimeter and
submillimeter measurements, it helps.
Energy systems need not also be solar. You can use
nuclear fuel on the moon just as easily as solar. I
would see the fact that the sun is blocked 50% of the
time as an advantage not disadvantage. Sure, you can
spend extra on shielding out the Sun for HEO, but your
increasing the costs.

> --- In ssi_list@... "Combs, Mike"
>
> I'm admittedly reading between the lines but doesn't
> this
> unnecessarily assume that the HEO telescope would be
> comprised of
> unjoined pieces. Without the constraints of gravity
> couldn't a metal
> wire run between all of the HEO components and join
> then together to
> assure unit integrity. Then just the entire unit's
> orbit must be
> maintained, not all of its pieces.
>

I'm admittedly reading between the lines but doesn't this
unnecessarily assume that the HEO telescope would be comprised of
unjoined pieces. Without the constraints of gravity couldn't a metal
wire run between all of the HEO components and join then together to
assure unit integrity. Then just the entire unit's orbit must be
maintained, not all of its pieces. I once read a paper by O'Neill on an orbital composite optical telescope, and I remember him commenting that running structural members between components would actually be something you wouldn't want to do, due to thermal expansion/contraction. He seemed to feel better control would be maintained via precise positional measurement and independent RCS. A bit counter-intuitive, but that's what the paper said.
On the moon, wouldn't the telescope face the thermal shock of
day/night. Another good point.
Regards, Mike Combs

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

>
> 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).
>

It is my understanding that for very long wavelength radio astronomy,
simple straight wires can serve as the antenna elements. This may be to
what the writer was referring when he said "wires can be laid". I haven't
followed this thread too closely, and cannot ascertain whether your
arguments have been limited to very long wavelength radio astronomy or
not. The laying of wires on regolith would not be a viable solution for
astronomy based on other parts of the electromagnetic spectrum.

Sorry it took me so long.

--- In ssi_list@... "Xenophile"
> Sorry it took me so long.

> What! No pithy signature-line this time. Tsk, tsk.

--- In ssi_list@... "Xenophile"

>>> I'm really curious about how that would be spent and to what