Joe Strout wrote in message ...
In article ,
(Ross A. Finlayson) wrote:

I guess my idea of a moonbase is a bunch of domes, using the
"regolith" as structural material.

Cylinders are more likely than domes, at least as a first step. And the
regolith is shielding material, not structural material.
...

That makes sense.

I'm wondering about "lava tubes on the moon". I guess I was under the
impression that besides Earth only Jupiter's moon Io had active
volcanic activity, and I was thinking Luna was a cold chunk of rock.
Yet, I read here that Luna has a molten, presumably iron, core, thus
that it would have similar magnetic fields to Earth.

Lava tubes, miles long underground caverns similar to lava tubes on
Earth, where higher temperature magma flowed out and left behind open
space, would probably be among the major geologic reasons for their to
be caverns on the moon with the lack of running water. I just had
never heard of their existence before yesterday, and don't know of any
on the moon itself.

I think there should be shortly ten or fifteen satellites about the
moon, these would be necessary for a variety of surface operations. I
may be wrong, the moon has no appreciable atmosphere, thus no
ionosphere and only line-of-sight radio communications. A satellite
array would be critical in providing global (?) coverage of
communications availability to surface operations.

About heavy lift, I agree with you in that smaller launches may be
more efficient. I guess I was thinking of heavy lift as total lift
capacity, but certainly the launch of very large items to not require
their assembly in space is also a consideration.

I always why there weren't more air-boosted launches, an aerodynamic
launch plane flies a hundred thousand feet high and the launch vehicle
separates and boosts to orbit from high in the sky. Maybe that's a
misconception from seeing the space shuttle flown around piggyback,
and about how high is low Earth orbit.

Geosynchronous orbit is much farther away than low Earth orbit, some
22,000 miles or something. Then, let's see, I think the moon is
600,000 (500-700) kilometers away, and Mars variously 20 million to
200 million.

I was reading about the Shuttle-C for cargo and saving the liquid fuel
tanks in holding orbits, I think that's a good idea. What prevents
the addition of new modules to the ISS, Freedom, the International
Space Station, every year? What's so great about the ISS's orbit that
it is there?

I got to browsing the "Lunar Prospector" web page, the probe that was
landed into the polar crater, almost.

http://lunar.arc.nasa.gov/resources/news.htm

Lunar Prospector was about first US moon mission since Apollo 17, then
there's Clementine.

About mapping the lunar surface and within it, I wonder if ground
penetrating radar instruments would be any good, for example for
discovering lava tubes. They might only work from the ground. We can
see the moon's surface pretty well from here and space telescopes. I
read that Mars Express is using some form of deep radar.

One of these documents from the website there have a low lunar orbit
being around 100 kilometers. Assuming that Lunar Prospector was
pretty conservative, it says the flight time to the moon, lunar orbit,
is around 100 hours, from LEO, low Earth orbit.

"From a given launch site, a launch to the moon is possible on each
day of the month, with two launch times (roughly 12 hours apart)
available on each launch data. ^3", from "Lunar Prospector Mission
Design and Planning Support" , referring to "A 70th Degree Lunar
Gravity Model (GLGM-2) from Clementine and Other Tracking Data."

The website has Lunar Prospector at around 63 million dollars (yeech)
in 1998. Mars Pathfinder, from the previous year, was much more
complicated as it had a lander in addition to the orbital component
and went to Mars, and research says it cost about 265 million. This
is where the Viking Mars probes from the 70s cost around 3 billion in
adjusted dollars. I guess what I'm trying to figure out is if a
mailbox full of cement was to be launched into lunar orbit, what would
be its costs?

Further research, I am not a regular follower of space industry news,
further research leads to information about the ESA's, European Space
Agency's, SMART-1 lunar probe that is using ion engines to waft it
gently from Earth orbit that was reached atop an Ariane 5 into lunar
oribt sometime in 2005, with a travel time to the moon of 18-20
months. A comment notes SMART-1 cost around 110 million euros and was
launched with two other satellites aboard the Ariane 5.

I have heard varying claims about the functionality of solar sails, if
they work they're definitely a consideration for long duration
orbiters as they wouldn't have to carry reaction mass for that system.
An orbiter could have both solar sails and ion/rocket drives,
redundant systems that if correct would allow an orbiter many years of
maintenance free operation, rockets for insertion and sails for
correction.

The newspaper says the current U.S. Mars missions tally to about 820
million, with Mars Express around 300 million euros.

http://www.esa.int/science/marsexpress/

International Launch Services here has some documents about the
capabilities of the Saturn and Proton families of booster rockets.

http://www.ilslaunch.com/missionplanner/

It seems pretty expensive to launch a payload into orbit. That's a
problem with monopolies, although I guess it's a market economy, there
are presumably some crazy regulatory controls on ballistic rocketry.

It's a lot easier to fantasize about thousands of launches per year
than to design/build launching something to the moon.

So let's see:

twenty space telescopes
space planes
twenty semi-permanent lunar orbiters
increased space station
twenty-two hundred moon rovots (roving robots)
ten semi-permanent Mars orbiters
ten Mars rovots

How about 1.5 billion dollars.

Hey right on, man.

Ross