Lava tubes not only supply thermal control, but pre-excavated micrometeorite shielding and protection from cosmic rays, solar flares, UV, etc. I do not see them as an immediate need, but as a logical nearer-term-than-most-imagine direction of lunar base expansion. Therefore, I think it shortsighted to put a major base where there is not local access to a lava tube or lava tube complex, FOR THOSE OUTPOSTS intended to develop industrially. All the same, there WILL be places on the Moon that we need to be (polar ice fields, highland Sudbury-like lodes of this or that strategic metal, science outposts) where there ARE NO lava tubes, and then we will have to do our best without them. But my prediction is that all of these "cellar less sites" will be secondary outposts in the long term -- that is not to say that they won't be crucial, and maybe intitially primary. The function of such other sites is to SERVE.
Non-Volatile Elements for Industry
For industry, far greater quantities of non-volatile elements will be used than water, carbon, and nitrogen, as essential as these latter are. At the poles, only the highland suite of materials richer in aluminum, magnesium, and calcium are generally available. Oxygen and silicon are everwhere. There is some iron, but not as much as in mare deposits, rich also in titantium. Maria ilmentite seems to be the most efficient and promising source of chemically processed oxygen, titanium, and iron. Some iron can be picked up from the soil anywhere with a magnet. For these reasons, along with the availability of lava tubes that obviate massive excavation and movement of shielding materials, and which can be used for major industrial operations, warehousing, and archiving (an Earth-serving lunar industry few, if anyone else, have foreseen) -- I have always thought that the highland/mare borders or coasts, or shores were the ideal place for eventual lunar industrialization. The closest mare or sea to a pole is Mare Frigoris, at 650 miles from the north pole, much better situated than any of the southern maria (Nectaris, Humoris, Nubium, Australe on the E limb). The clincher to this argument is that it is these "coastal" sites are the same kind of sites that happen to be the regular haunt of lava tubes.
The south polar crater rim, "Mt. Wasser," has discontinuous sunlight, not necessarily all at the same spot, for 86% of the time. YES, that IS better than 50% of the time as David Gump points out. For other sites away from the pole, there are several non-nuclear energy storage options for excess energy produced by unlimited dayspan sunlight (fuel cells; underground pools of molten regolith melted during dayspan by solar concentrators, to be paired with thermal generation of electricity; still other options), plus the possibility of -- to some significant extent -- SEPARATING OUT industrial and maintenance activities into (1) those that are energy-intensive (and ideally manpower-light) to be conducted principally during the dayspan fortnight, and (2) those that are less energy-intensive) (and perhaps labor-heavy) for taking care of during the nightspan fortnight, resulting in a welcome natural rhythm, that may become part of lunar settlement culture. This is something for "operations engineering" and, to a very limited extent, we already practice this "operational discipline" in some industries on Earth to even out peak and slack power demand periods.
NASA never attempted thermal control elsewhere during the Apollo science picnic adventures. It is available first of all by shielding, now taken for granted by NASA in current lunar outpost design, and by lightweight shading canopies or ramadas over areas of frequent and routine outdoor activity, and by portable canopies and sun-breaks for field work. There is no atmosphere so, actually, the high temperatures so often quoted of the dayspan period are largely superficial and easily baffled. There are two things to consider here. DIRECT exposure to the Sun (at noon on the equator, this is only a person's footprint, whereas at ANY time at the pole, a much larger area of a person's front or back or side actually catches the sun). The second thing is heat REFLECTION off the surface, much more of a problem away from the poles, where the Sun-angle is higher. Now Apollo astronauts were on the surface only during "morning" pre-noon hours/days. But halfway from dawn to noon on the equator, IF SAFE, means that high noon at 45 degrees north or south are safe also = same maximum solar elevation. Etc.
Bases in Our Future
Where to put A FIRST base is not the same question as where to put THE base. I won't address the latter question. There is no point in going back to the Moon if we are not aiming at a global multi-site presence involving resource-using industry. We SHOULD be talking about where to put the "first" base, and this is a strategic consideration involving which scenario offers the best leverage for further expansion. I don't wish to prejudge the outcome of that brainstorming exercise, only to prevent a premature rush to judgment by polar base fans, generally looking at near-term considerations only.
Now the polar site, like the Alaska North slope, is A GAS STATION. Believe me, we won't build a future Lunar Los Angeles there (just as we haven't in Alaska). We don't need the polar site's high powered cryogenics (liq. hydrogen, oxygen) for return-to-Earth flights. The Moon's gravity well is very shallow, and we can boost off the Moon with OTHER local fuels, such as powdered iron (or aluminum) and liquid oxygen. Where cryogenic hydrogen becomes MUCH MORE LEVERAGING as a fuel is for refuelling spacecraft bound for Mars and elsewhere beyond the Earth-Moon vicinity AND for refuelling MOON- BOUND craft in LEO for the OUTBOUND LEG. So we might well see, and want, a very early, even an initial, cryogenic hydrogen "harvesting" facility at the south or north poles of the Moon to help bootstrap GENERAL lunar development. I see tankers taking liq. H2 back to LEO. But Moon-bound ships fuelled with lunar liq. H2 do not need to land AT the pole since they do not need to refuel there. They can go ANYWHERE we want to do meaningful stuff on the Moon. That might mean installing and servicing a farside radio astronomy complex. It might mean errecting lunar solar power arrays (a la Criswell) on the Moon's limbs (e.g. Mare Marginis, Smythii, or Australe on the East Limb; Lacus Veris or Mare Orientale on the West limb). It might mean an equatorial highland/mare coast area where we mine materials to shoot into space by a mass driver for use in space contstruction. It can mean a major industrial complex near the "shores" of some mare, with handy lava tube access for major expansion.
So really, the picture looks different if (a) we are talking about one initial base which may be all we ever get (a defeatist and dead end posture which I urge all to reject) or (b) we are looking at the long-term incorporation of the Moon into a wide-ranging Earth-Moon economy involving significant settlement. The trouble is that many long-deprived space advocates are willing to settle for (a). Sixty-six years hence we will be as far beyond that one & only initial outpost as we are now beyond Little America (1932) on Antarctica. Option (a) is a wooden nickel, and if there are numerous fellow travellers ready to settle for that, as leaders of the more farsighted section of the space movement, we have an obligation to look beyond, and to telegraph that wider, far-ranging vision to the public and media. Base One is just that -- "one of a series," a Beachhead, a place where we learn better how to interface with a new world. It is just a gambit, but we have to make sure it is a gambit that leads into an open-ended game, not to a checkmate in just two moves.
I personally feel that, while the thermal management advantages of a polar site are real, they are exagerated, and are sustained largely by dismissing imaginative ways to do thermal management elsewhere. I also feel that around- the-sunth (as I have dubbed the combined dayspan/nigtspan period after a long look at alternative monickers) availability of solar power are exaggerated. No one is being honest about one of the severe drawbacks of a polar site: the Sun just grazes the horizon -- that means extremely long shadows, and very difficult negotiation of the terrain for either vehicles or suited personnel unless they are equipped with very powerful headlamps or operate in a very intensely artificially lit area.
There will be adaptation challenges wherever we go, and nothing is to be gained by not realizing that human ingenuity has ALWAYS risen to the occasion, however extreme and inhospitable conditions seem at first blush. Once we get to know how to deal with local conditions, and doing so becomes second nature, as is sure to be the case, we will wonder what all the fuss has been about.
Meanwhile, Lunar Prospector's findings are great news. But let's all keep in mind, and not exaggerate -- this water ice endowment is very TENUOUS.
WE NEED TO KEEP BRAINSTORMING these lunar opening SCENARIOS. BUT we must DO SO AWARE THAT WE WILL HAVE HOPEFULLY MUCH MORE DETAILED LOCAL INFO ON WATER ICE IN just ONE YEAR, after Lunar Prospector, if it is still operating well, goes to a much lower orbit for a closer look. We will then have a much better map of the permafrost areas and, hopefully, a list of some areas in which the ice resource is much more abundantly present, promising a more economic operation. Right now, this polar frost seems to be, on average, only one or two orders of magnitude richer in hydrogen than the background solar wind topsoil endowment. And add to that Binder's admission that his estimates could be too generous by an order of magnitude -- let's hope any error is in the other direction.
We all stand to gain if we find areas where ice is more abundantly present. DO START POINTING OUT TO THE MEDIA AND THE PUBLIC that where there is comet- derived water ice, there is also certain to be intermixed carbon oxide ices, some nitrogen and other stuff, which in the end we will ALSO NEED JUST AS MUCH as water/hydrogen.
DO START promoting a look at the Moon's future that transcends a single "THE" outpost. We now all suffer from a "THE" space station mindset. Let's take the long view. We have to start selling space by the WHOLE LADDER, not just one rung at a time. We need to give the public the greater picture.
Topics for ISDC '98
One of the initiatives to be taken at ISDC '98 will be a workshop to produce an EZ update curiculum binder on the "Economic Geography of the Solar System." We need to start teaching our kids that what's out there is more than a neat zoo of celestial objects -- they are places where humans can live and WORK and play. You all know what economic geography is -- the series of maps in your atlas that show not just mountains and rivers and cities and borders, but where is the iron, the copper, the aluminum, the hydroelectric power. Where wheat is grown, and corn, and rice. Where hogs are produced, and cattle, and sheep. Where the ocean trade routes are, with thickness of the lines keyed to volume of traffic. This curiculum does not exist.
We have some seminal works, on asteroid resources, and on the Moon ("Lunar Sourcebook: a User's Guide to the Moon," Ed. Heiden, Vaniman, French). To this we can now add Lunar Prospector's findings, with a further update next year. Results from NEAP if it becomes real. Results from Tom Billings' lunar lava tube detection mission project (another ISDC 98 workshop). All of this will help illustrate how the Moon and other bodies are potential friendly places for prosperous human economic activity.
Your support and interest in the economic geography workshop at ISDC 98 is invited.
Meanwhile, kudos to us all involved in making the dream of Lunar Prospector come alive over the past 11 years. Gay Canough will tell everyone that it is I who recruited her, who then recruited Greg Maryniak, who then recruited Al Binder at Jim Davidson's March '89 Lunar Polar Probe Conference. But I would not have been a player in Denver in '88 had I not been responding to Rick Tumlinson's charismatic and electrifying lunar polar probe fund-raising effort at the Pittsburg ISDC in March '87. So hats off to Rick. And, of course above all, to Al Binder for doing the real work, and for too many lean years of perseverance. In comparison to Al Binder, the rest of us are humble footnotes, priviliged to have been in the right place at the right time to serve as a link. It is still a great victory for the grass roots movement.
Some may bring up the "colony" vs. "settlement" argument. I personally think, that in the context of space, especially on bodies known to be empty of other sentient life, the question is moot. It is time to countereducate the public, that at least the Solar System seems to be destined human hinterland by default. It will be a long time after all of us are dead and forgotten that contact scenarios arise.
Peter Kokh, Lunan ancestor, Chair ISDC '98, Ed. Moon Miners'Manifesto