On Sat, 10 Jan 2004 11:38:25 -0500, Alan Figgatt
wrote:

Tom Abbott wrote:
My comments in [brackets]
[With the use of large-capacity cargo launch vehicles, we
can eliminate this problem. We have the perfect launch
system to do this, the space shuttle launch system. Instead
of launching space shuttles, we can launch cargo and
propellants, using the space shuttle's launch system (the
large orange External Tank (ET), the solid rocket boosters,
and space shuttle main engines, among other things).]

You seem to be fixated on using the shuttle launch system for sending missions to the
moon.


You are very perceptive.


The shuttle launch system was designed to launch shuttles to LEO, period.


So? It's design will allow other things to be launched,
too, and not just to low-Earth orbit.


The 3 SMEs
are on the shuttle - you would mount them on some new return vehicle?


That's one option. Another is to parachute the "boattail"
that would contain the Shuttle main engines back to Earth
for recovery and reuse. Another option is to use old
shuttle engines and just take them into orbit with the
payload.



No, if you are going
to build new capsules, manned round trip lunar landers, and unmanned one way lunar
habitation landers, you might as well bite the bullet and build a new grandson of Saturn V
launch system for it.



Why do that when it would cost more money to redo the
Saturn V, than to convert the space shuttle launch system
into a heavy-lift cargo launcher?




I could see using an upgraded Delta IV heavy to send small cargo supply ships (such as
Progress does) to the moon and ISS.



The more tonnage one can put in space at one time, the
cheaper the program is going to be. I don't think the Delta
IV can come close to competing with the shuttle-derived
heavy-lift vehicle on costs and it certainly cannot compete
on simplicity of operation.



A colony on the moon almost certainly would require an
atomic reactor for power.

[No, this is not necessary for the Moon. Solar power
would be more than sufficient. A reactor might be needed on
Mars, though.]

Solar power would work for the 2 weeks of sunlight. The lack of atmosphere does help in
that the solar power output would be constant (with a tracker) so long as the sun is above
the horizon - no clouds or atmospheric attenuation to worry about. But what will you do
for power during the approx 2 weeks of night? You could, and likely would, use the solar
power to charge up a battery bank. But a battery bank big enough to last 2 weeks would
present serious weight and thermal issues (have to keep the battery temperatures up).
Perhaps they could use RTGS for power during the night in combination with batteries, but
that would present sever power constraints for the base.



Yes, I was thinking about a battery bank in this instance.
The battery bank is not such a tough option if we are using
heavy-lift launchers. I would have to do some homework for
exact figures, but if memory serves, it would require about
a 40-ton hydrogen/oxygen fuelcell which a shuttle-derived
heavy-lift launch vehicle could put on the Moon with two or
three heavy-lift launches, depending on the exact
configuration.



No, a compact and reliable nuclear reactor is something that needs to be developed if we
are to get serious about permanent space colonies. But this will be a significant cost
item and controversial to boot with the anti-nuke crowd.



I agree, but I think NASA is currently working on just
such a device, and I haven't heard much from the anti-nuke
people about it. They are strangely silent.



I would expect the first several return to the moon missions will be limited to daylight
visits only. But even a 10 day stay is still 3 times longer than the Apollo missions.



Using a shuttle-derived heavy-lift launch vehicle, we
could put a 30-ton Moonbase on the Moon, complete with
energy and supplies to last 12 people for 90 days, using
just one launch. There's no reason why the first crew on
the moon cannot stay at least that long, barring something
unforseen.

And there just happens to be a design for such a Moonbase
using a converted oxygen tank from the External Tank.
Or a similar structure could be developed using an Aft Cargo
Carrier (ACC) that would mount below the External Tank on
launch. This could be put in low-Earth orbit with a normal
space shuttle launch and would not require a heavy-lift
vehicle. But the 80 tons or so of propellants and oxidants
*would* require a heavy-lift launch vehicle in order to be
cost-effective and to keep the project as simple as
possible.


Alan Figgatt





TA