MMM Classics Year 10: MMM #s 91-100 - Moon Society

circumference of 5.655 km or 3.5 miles and a usable surface
area (lower slopes included) of about 50 acres.
With multiple levels, it was estimated some 10,000
people could occupy 106 acres (Manhattan like sardine
packing, i.e. quite dense by modern urban standards of c. 5,000
people per square mile = 640 acres.) That seems overdoing it
especially since off Earth settlements wherever they are will
first and foremost be farming villages: = lots of plants hosting
very few people, not vice versa.
But thanks to the copious artwork that has
accompanied the settlement design studies of the seventies,
such a torus does give us an assist in conceptualizing a
lavatube settlement. Cut it at one point and unroll it, and you
have something comparable, if on the small end, to what we
might someday see in lavatubes. The average lavatube is likely
to be several times wider than the torus of the NASA study.
interior torus view, art by Pat Hill, IBID, p. 90
In practical fact, however, this scene gives us more of
a goal to hold before us, than a model for feasible near term
reality. Sealing a lavatube so as to pressurize it may be easier
said than done. If we succeed, filling the immense volume with
the usual buffer gas of nitrogen imported from Earth in a 4:1
ratio with lunar oxygen may be budget-busting. But more on
this in an article below.
Near-term, pressurized ceiling clearances will have to
be kept to a minimum. We will use lavatubes at first not to
escape the vacuum, just to escape the deadly cosmic weather
that normally comes with vacuum - on the exposed surface.
The tube ceiling vault functions analogously to the
Biblical “firmament” protecting Lunans in their hidden valleys
(lavatubes) from cosmic radiation etc. and from the otherwise
omnipresent dust. Even if the tube is not sealed and pressurized
it may be feasible to spray a high albedo coating on the upper
walls and ceilings (CaO lime, or Aluminum Oxide or Titanium
Dioxide, all producible cheaply and in quantity, are white. The
trick is to make an anhydrous “whitewash”. Unfortunately,
bluing this inner “sky”, e.g. with locally-producible cobaltous
aluminate would be expensive.
Sunshine could be brought in down simple shafts or
through optical cable bundles, to be turned on this sky-firmament,
thus providing comfortable daylight type ambient light.
During nightspan, nuke or fuel-cell powered lamps on the
surface could use the same light transmission pathways.
Possibly any whitewash material on the upper vault of the tube
could have a phosphorescent component for a night span treat.
Imagineering, it is called.
KEY: (a) sunshine access and defuser system; (b) whitewashed
“firmament” for best sunlight reflection; (c) “town deck” on tubespanning
beams; (d) assorted structures; (e) “yurt/ hogan” type
home with translucent dome to flood interior with firmamentreflected
sunshine; (f) monorail transit system; (g) lavatube floor
left natural; (h) nature walks.
Instead of grading or even terracing the lavatube floor,
it could be left natural with the town built on a spaceframe
deck spanning the lavatube shoulder to shoulder. an overhead
crane riding rails along the sides of this deck could be useful in
constructing/erecting habitat structures. The use of stilt platforms
is a possible alternative to the deck span, shoulder to
shoulder beams
Elevators to the surface can either be incorporated into
“skyscrapers” reaching to the tube ceiling, or be built freestanding
to provide great views of the town on the descent
from or ascent to the surface.
Access to the settlement from the surface is vital. This
Moon Miners’ Manifesto Classics - Year 10 - Republished January 2006 - Page 93