Not So Picture Perfect: Proposed Lunar Landing Site Has Drawbacks

The hype for the "perfect site" for a first moonbase at the Moon's south pole (Mt. Malapert) and more recently for a rival north polar site, continues to get good press, and to all appearances, just about everyone is on the bandwagon. I have serious reservations, however, and have found that there are others who share them, but find it difficult or unpromising to buck the trend.

A north polar site has the great advantage of being less than half as far away from the nearside maria complex as the South pole. The North pole lies just 600 miles north of the North coast of Mare Frigoris, whereas the South pole is 1300 some miles south of the southern coasts of Mare Humorum, Nubium, and Nectaris.

Industrially, the highland/mare coasts have much to offer with the availability of both major suites of regolith; highland regolith enriched in aluminum and calcium, mare regolith enriched in iron and titanium.

The nearside mare complex embraces all the nearside maria except Crisium in one interlinked area of relatively easy to traverse terrain and represents 39% of nearside. Add to that, highland areas handy to the coasts.

The problem with the polar sites is that they are ghettos. These places of "eternal sunlight" are surrounded by very inhospitable terrain. We will be on very uneven, even mountainous terrain with very confining and limited flat areas. The shadows will be extremely long and dark and the shadow pattern will be constantly changing, making visual cues as to one's whereabouts or heading all but meaningless.

The whole idea of going to the poles, is not to tap ice (that's just "frosting on the cake") but to escape two requirements of settling in anywhere else:

1. Having to store up power during the two-week long dayspan in order to power equipment and systems during the two-week long nightspan
2. Being able to avoid the problems inherent in incessant bimonthly cycling between extreme hot and extreme cold.

If we tackle those problems head on from the start, then we own the whole Moon. If we do not, then we only own tiny turflets at one or both poles while the rest of the Moon remains off limits.

On point [1] - "eternal sunlight"

I believe that the "eternal sunlight" is available not at one precise point, but at a string or chain of spots around a high point rim or massif at either pole. If that is the case, it may take a significantly greater mass of equipment shipped to the Moon's pole (either) in order to set up a power system that will have solar input most (but still not 100%) of the time, than it would be to set up a system elsewhere that would store up excess dayspan solar input for nightspan draw.

Further, we will still need such a power storage system at either pole, for those periods, however minimized, that the sun doesn't shine.

To me, the search for the eternal light brings with it the inherent drawbacks of: putting us in very small local areas surrounded by much more challenging polar terrain, putting us where we have no, or greatly reduced, access to iron and other industrially essential elements more abundant in mare regolith. Both poles are highland areas.

putting us in a place from which it is hard to travel overland to anywhere else still needing to have a power storage system on top of a more massive system of solar arrays linked by cable around the polar mountain or rim crest having to set up shop in relatively non-flat areas. Laying out the extended solar power array system in mountain terrain, involves high risk to personnel and equipment.

This euphoric "eternal light bandwagon" gripping perhaps most lunar enthusiasts and supporters seems all very much like the momentary delight and anticipation of the moth that sees a bright porch light or street light, and is drawn instinctively, unsuspectingly, to its certain doom. Yes, we need water. But we need more iron and other materials. So is it better to ship X tons of water to sites away from the poles, or 10X (to grab a figure) tons of other materials to the poles? The answer to that question seems to me to be a "no-brainer".

But if you are someone who doesn't put much stock in the potential for lunar industrialization, and who is only attracted to the polar ice reserves because in addition to a supply of drinking water, they can be turned into rocket fuel to support exploration, not of the Moon, but of the rest of the solar system, then the polar sites offer just what you need. That you bring the Mountain (larger tonnage of mare/highland regolith needed) to Mohammed (ice) or bring Mohammed to the Mountain, is not a consideration. But consider: did we build Los Angeles next to Prudhoe Bay?

You don't feel trapped at the poles, because the whole idea is to establish a token presence on the Moon, maybe with a token telescope to boot, and to leverage that for fueling other solar system endeavors - You dismiss prospects of lunar industrialization and settlement.

Now David Schrunk and his team have indeed developed a very ambitious scheme to use peak of eternal light sunshine to power a lunar railroad network which will eventually extend over much of the Moon. A lot of work has gone into that proposal in his Book: The Moon : Resources, Future Development and Colonization, and I deeply respect that, and highly recommend the book(*).

The poles will be part of the lunar future. I just think that they should play a supporting role, not the lead.

We need to get our feet wet on the Moon in a way that will allow us to roam free on the Moon, virtually every-where, not writing off the 99.999% of the Moon which is not "eternally sunlit."

It is not that difficult to design a system that traps excess dayspan solar inputs for nightspan draws -- there are several workable options and all ought to be pursued (let the technology pick the winners!) And/or (I prefer and ) we can rely on a nuclear power plant (as backup -- who ever heard of a nuke that never went down?) So let's pursue this harder path, because it is a path that leads to everywhere, not just to a tiny polar cul de sac.

If we bring earth-moving equipment to the Moon that heats the soil and extracts the trapped solar wind gasses in the process -- whether we are building roads, grading sites, or gathering material for lunar processing, or to be transformed into agricultural soils for those plants that do better in geoponics than in hydroponics -- then we will have all the hydrogen we need for drinking, agriculture and other biosphere needs, and for industrial processes in which the hydrogen is recycled.

If we don't want to develop such equipment or bring it to the Moon, then why bother going? The Moon is an uphill battle. If we don't "What is worth doing, it is worth doing right."

Finally, point [2] avoiding temperature swings

If we properly shield our habitat structures, either covering them directly with regolith or regolith-filled sacks, or placing them under regolith shielded hangers (an option that makes both maintenance and expansion easier), then the temperature cycles will not affect them. These modules will be at constant temperatures (the seasonal swing on the Moon being less than 3 degrees (Fahrenheit, I believe) a couple of meters below the surface.

The problem, rather, will be for those exposed structures, equipment, and vehicles. We need to build them to withstand the heat of high lunar noon (all the Apollo missions were conducted in "mid-morning" conditions.) as well as the intense cold of the lunar night.

Look, if we are not going to trap ourselves forever in very tightly confined polar sunshine ghettos, we had better learn how to handle the thermal cycles right away. If we postpone doing so, that postponement may well last decades, if not forever. We have what happened after the departure of Apollo 17 from the Moon in support of that grim prospect. Let's not pull our lunar punch!

We need to build things out of materials with a minimum of thermal expansion - reserving high thermal expansion materials for sheltered usage only.

We need to develop seals that can handle the temperature swings. We need to develop lubricants that can handle this thermal cycling or finding ways of shading lubricated areas from direct sunlight and heating them when need be. Silicone-based lubricants (oils and greases) are much better than hydrocarbon-based ones in this respect. Super-magnetic bearings may be part of the solution.

Argument Summary

We should/will go to the poles, eventually, to tap water ice, and use permashade to site telescopes that need cryo-thermal conditions. The North Pole is more conveniently situated to the maria than the south pole - [Galileo photo N Polar area] http://www2.jpl.nasa.gov/galileo/images/north.html

For water-ice access, considered separately, permashade deposits are likely to exist up to 400 miles south of the North Pole, or north of the South Pole, for shortened access to the nearest mare coasts. This means perhaps 200 miles or so from the North coast of Mare Frigoris to the nearest likely north polar ice field, and 900 miles or so from the South coast of Mare Nubium to the nearest plausible south polar ice field. "Go north, young man!"

The government is likely to build only one lunar outpost. To put it in a place from which we are equipped to go nowhere else, puts us in a self-chosen ghetto. Those to gain most from such a site selection, at either pole, are those who have their eyes set on refining hydrogen for use as cryogenic rocket fuel for off-lunar transportation, those who are skeptical about, and uninterested in, the development of the Moon's resources in a way that will lead to substantial real settlement. At best, we will end up with something akin to a North Sea Oil Rig Platform or an Antarctic science outpost. The "escape path" that Schrunk et al. have outlined, while brilliant, is, I fear, unlikely to be followed. We need to tackle the lunar problems of power storage and thermal cycling head on if we really want the keys to the Moon at large, not just the key to a "lunar closet."

So NASA does what it wants to do anyway

So what if the path (and fate) of moths is pursued anyway? In the long run, the Moon will be developed by business and industry, not by the government. They will find a way to do it right, because nothing else makes sense. However, the establishment of a government moonbase at the poles will be unhelpful. The equipment and systems developed by NASA for a polar site will be specialized for conditions that exist nowhere else (except, possibly at the other pole!). Thus the R&D burden facing commercial and industrial users will remain untackled. So such a misguided polar siting of a NASA base will defer, rather than hasten, commercial development on the Moon.

What is easiest is not always best. The right way is usually the hardest one. If we have the right stuff we will pick that road. If we do not, we will deserve the dead-end future of the moth fascinated by the light.

Reference: The Moon : Resources, Future Development and Colonization by David Schrunk, Burton Sharpe, Bonnie Cooper, and Madhu Thangavelu..

John Wiley & Sons; (October 22, 1999) ISBN: 0471976350 Hardcover. 432 pgs

Peter Kokh is president of the Lunar Reclamation Society (NSS-Milwaukee) which he helped found in 1986, and since August 2004, President of the Moon Society. But his opinions above are stated only in his capacity as editor of Moon Miners' Manifesto (www.moonminersmanifesto.com) a newsletter now in its 19th year of continuous monthly publication.