Lunar Base, Island-A ideas and why Zubrin was only half correct. (l

>>>>Damn, the asteroids are so far! I was looking forward to a lunar
colony, one with domes and all. I would like being a geriatric there
instead of here on earth.>>>>

Good on you. I have been examining the costs of operating a lunar base in
connection with the O'Neill concept. The results are extremely promising.

I assumed that a lunar base, equipped with Hab, mass-driver and 20 1-Mw
nuclear reactors, would about 600 tonnes. The base is maintained by a crew
of 3. The crew are replaced on a 2year-3month schedule, so I assumed that
an extra 75 tonnes would need to be delivered to the base over a 7 year
period. That's a total of 675 tonnes. At current launch prices, assuming
zero development and administration cost, the base would cost a total of
$8.1billion, using the Russian Protons for delivery. With 20Mw of power,
and a 60% efficient mass driver, the base could deliver 944,000 tonnes of
material to L2, over a seven year period. Assuming a total payback, zero
profit scenario, that's just $8.58/Kg! This does not take into account any
admin, or development costs. It also assumes that we can deliver payloads
and people to the moon for $12,000/Kg. But even if we have to triple that
cost, its still only $26/Kg to L2. That's about 200 times lower than the
price of delivery by ordinary Proton booster to HEO.

And all of this assumes that we don't bother refuelling the reactors
after seven years. If we do that, we only have to pay the price of shipping
a new batch of fuel (weighing 10 tonnes at most, for all 20 reactors), a
mobile, tele-operated refuelling machine (2 tonnes?) and a crew replacement
(75tonnes) to the moon, on the 7th year, for a 7 year period.

(87,000Kg*12,000$/Kg)/944,000,000Kg = $1.1/Kg in launch costs.

The HEO workshop that is required in order to manufacture useful products
from the lunar materials, will cost more. We would probably start out with
a small facility based inside a single shuttle external tank. The H2 tank
can be converted into a series of workshops, materials processing
facilities and living quarters. The smaller O2 tank could function as a
satellite assembly bay, with large shuttle-type hanger doors, for satellite
launching. The initial facility would probably be used to construct
military and communications satellites, in order to partially offset the
cost of start-up operations. If we assume that the launch costs of placing
a communications in GEO are $5000/Kg, our manufacturing facility should be
able to undercut Earth-side satellite manufacturers by a factor of between
10 and 20, $250-$500/Kg.

In the mean time, most of the imported lunar material could be used to
produce a larger, better equipped manufacturing facility, which I call
Island-A. This facility would be much larger than the cramped external tank
and it would house a far more capable manufacturing facility. I initially
assumed that Island-A would be a sphere 40m in diameter. But with so much
material to work with, we could afford to build a facility 100m in
diameter, if we so wished. The total internal volume of the sphere would be
enormous, more than half a million cubic meters. The 100m diameter workshop
would rotate in order to produce artificial gravity. The interior of the
facility would be divided into a number of concentric cylinders. These
cylindrical floors, would be divided into various workshops, materials
processing facilities, living quarters and farming facilities. The
materials processing facilities would process the imported lunar materials
into feedstock materials such as pure Iron, Aluminium, Calcium, Silicon,
Titanium, Magnesium and oxygen. These materials would then be crafted into
satellite and space station parts, within the manufacturing workshops.
Along the rotation axis, a cylindrical satellite assembly hall, perhaps 40
meters in diameter, would run from pole-to-pole. Large satellites and space
station modules, would 'hang' along the axis of rotation, while robots and
workers hurriedly assembled them. Smaller satellites and satellite parts,
would be assembled in manufacturing workshops. A large airlock, for
satellite and space-craft launches, would sit at the end of the assembly
hall. A smaller airlock on the other side of the hall, would be used for
spacecraft docking.

Perhaps one of the first tasks that island-A would be required to
perform, would be the expansion of the lunar base. After about 15 years,
the nuclear reactors and mass driver at the lunar base, would be nearing
the end of their lives. A larger facility will also be required, in order
to satisfy a growing space market. Large mass drivers, hundreds of meters
long, could be manufactured within the workshops and assembled into folded
packages within the assembly hall. Solar panel's and nuclear reactors could
both be produced using the vast array of workshops and equipment within the
manufacturing facility. Within 10 years of the start of the program, the
crew of the 100m diameter island-A, would be ready to build a fully fledged
island-1 colony. By this point, lunar material would probably be cheap
enough for the workers to consider building a proto-type SPS.

Interestingly enough, the cost of lunar material from an initial lunar
base (during the first 7 years or so), is probably close to Zubrins $30/Kg
estimate. After 10-20 years of continuous growth and increasing
manufacturing ability at L5, it could fall as low as $1/Kg, for finished
products.

Tony