Lightship

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Lightship Page 23

by Stephan Besik


  Chaz shrugged. “Possible. This is just the first of some pretty big problems, though. The variation of charge on the Moon’s surface is also a substantial issue. Apparently voltage variations of several hundred volts can arise across relatively small areas of the Moon’s geography, so it’s necessary to make sure there’s a way to stay grounded. It doesn’t seem to be a problem if a machine or a man stays in a limited area, but over a distance, say between the top and bottom of a hill, the voltage drop can be pretty large. A discharge of a few hundred volts would give us our miniature lightning strike, and most electronics don’t take kindly to that sort of variation in their environment.

  “There are also things like the four-week long days that cause overheating in the day and sub-zero freezes at night. Add that to a locally charged surface and clingy, superfine dust and there are a fair number of difficult environmental issues. Temperature variations just add increments to the other problems.”

  “So, do we have an approach or are we stuck?”

  “We have suggestions. Suggestions that we think can be implemented. Whether our solutions will work…” He shrugged again. “We can find out quite a bit here on Earth, as well as in space. But we won’t know for sure if our solutions work until we actually get there.

  “For example, we have ways of sheltering our lunar station, or stations, from the solar wind. The easiest seems to be locating as much as we can in caves. If we can’t find natural ones that are suitable, perhaps we can create what we need. That’s probably the easiest thing we can do.

  “The problem with these solutions is that they aren’t complete. There are going to be things at our lunar station that have to be on the surface, exposed to the solar wind. Right offhand, two examples come to mind- research facilities like observatories, and energy producing facilities like solar energy farms. For these we need a surface solution, and the best one seems to be a man-made version of Earth’s protection. That’s some form of a magnetic shield. Such a shield will be the first of its kind, and it’s nearly certain that any lunar station, even an automated one, will be some kind of hybrid that mixes facilities in caves or other forms of shelter with magnetically shielded resources on the lunar surface.

  “There may be an intermediate solution, too, between having to provide magnetic shielding for fully exposed installations and burying things in caves. A third option is to build facilities in canyons. Ideally, a canyon installation would be moderately deep and narrow, to provide shelter from the solar wind, and perhaps moderate the temperature extremes from full sunlight to stellar dark. Canyons might also be sheltered enough to eliminate or greatly reduce the amount of sputtered dust from the solar wind.”

  Chaz took a breath to start another topic. He wasn’t used to long presentations, and this one was going to be pretty long.

  “Caves, canyons and a magnetic shield reduce the likelihood of solar wind damage in the foreseeable future. But what about the damage that has already been done? In particular, what do we do about facilities that really have to be fully exposed on the lunar surface? Facilities that will be exposed to moon dust and voltage variation?”

  “There might be an easy solution. Our idea is to use plasmas or lasers to melt the dust. Once melted, the dust will cool and reform as rock again. Carefully done, it’s possible that melting the dust will result in fairly even, possibly even smooth, platforms on which to build. That would turn the dust into a building material. We might also be able to use the solidified surface as a roof for a subsurface structure. Remember that we have to find a way to protect our resources from the solar wind.

  “It’s likely that we will use some kind of high-energy laser to do the melting, but at this point plasmas can’t be excluded. There are some scenarios in which a plasma sprayer of some sort may be the best solution. We have to do some R & D to make our decision.”

  Chaz continued. “So we have what appear to be feasible solutions to the problems represented by items One, Two, Three, with possible moderation of item Four. Now we have to deal with item Five, or more generally the availability of elements critical to the survival of humanity on the Moon.

  “The most amazing thing about the Moon is that there is a great deal of oxygen locked up in rocks on the Moon’s surface. With the solar wind bombarding the surface with what are essentially disassociated hydrogen atoms, we have not only oxygen but the other constituent of water in quantity. In answer to your question about air and water, Danny, we can crack oxygen out of Moon rock. As for water, there are not only deposits of water ice in areas not exposed to the Sun, but we may be able to use the solar wind to help create water. We could find water ice as we search for canyons to protect our installations. Properly designed, a facility to assemble water molecules and store water ice might be created out of some of the canyon territory that we will looking for anyhow.

  “There’s not a lot of water on the surface of the Moon because water is volatile and simply evaporates off of most parts of the Moon as soon as it is created. The solar wind is the source of hydrogen ions in the heat of the lunar day. At the time during which water is likely to be formed it will evaporate, probably within seconds (or microseconds) of the hydrogen and oxygen atoms getting together.

  “We have another limited answer to the problem of water because there are places on the Moon where water ice appears to have accumulated, and there is probably enough water ice to make a small population water self-sufficient. Perhaps this situation is like sputtering, only beneficial. It could be that over millions of years, certain types of terrain are sheltered enough to create water and hold on to it. But no matter how water has been formed on the Moon, there is evidence that there’s a fair amount of it available.

  “If we can find water ice, there may be no need to try to generate water from available resources and store it somehow. We may be able to do ice mining for quite some time, since some estimates of the availability of water on the Moon suggest the supply is enough to last many decades, if not centuries. If the lunar population isn’t too great water may be available indefinitely, especially if we efficiently recycle it.

  “There are also substantial quantities of elements like silicon and iron, even titanium, stuff to make things with. This is one of the major positives of an effort to inhabit the Moon. Concerns about oxygen and water may not be all that significant and there are other quite useful elements on or near the Moon’s surface.

  “There are some things that are missing, however. Things that are quite important to life on Earth, and that will probably be critical to survival on the Moon. The two most important elements that appear to be in short supply are nitrogen and carbon. We tend to think of Earth’s atmosphere as composed primarily of oxygen, but as you know nearly eighty percent of the atmosphere is nitrogen. It’s all over the place down here and it’s in a lot of things that humans need to survive.

  “Carbon is needed as well. It is a fundamental component of organic compounds and also has some important uses beyond that. No carbon, and humans won’t be around very long. The problem on the Moon is that there isn’t much carbon in the ground and no atmosphere full of nitrogen. Both carbon and nitrogen are trace elements on the Moon’s surface.”

  Danny spoke up again. “I’m not sure why you’ve got the lack of nitrogen and carbon as long-term problems. Seems to me that could be a concern pretty quickly.”

  Chaz nodded. “It could be, but the need is so critical that we simply can’t go to the Moon if we don’t carry nitrogen and carbon with us. They are in us, they are in our food and the wastes we produce, and nitrogen pretty much has to be available in the atmosphere we create. In effect we are importing carbon and nitrogen from the first minute we step on the Moon.

  “This is a bit like our problem of holding on to oxygen and water. What we have to do is hold on to the carbon and nitrogen that our lunar explorers bring with them. We have to make the environment for our people as efficient as possible with recycling, so that we don’t waste the elements we bring with u
s. Over the long term, we hope to minimize losses so that we only need to bring additional nitrogen and carbon to the Moon to replace those small losses. For example, if we want to grow food on the Moon we can use waste products from people and perhaps animals. That’s the way primitive peoples have done it for centuries, to provide most of the nitrogen and carbon needed. But no process is ever one hundred percent efficient so there will have to be injections of new material from Earth or somewhere else to make up for any losses in our processes.

  “One of the Moon’s paradoxes is the lack of surface carbon. Carbon happens to be the fourth most common element in the universe, and yet it is available only in trace amounts on the Moon’s surface. Is it possible that there is carbon below the surface somewhere, carbon that could be mined? If so, we have a long-term solution to our issue. And if not, why not? Where did it go? If we don’t have naturally occurring carbon on the Moon, can we bring it in cheaply?”

  Chaz took a breath. “So those are the major issues. Some of the problems require nearly immediate solutions, like a shield from the solar wind and a solution for the dust. Some are probably intermediate, like generating oxygen and water to reduce the need for imports from Earth. Some are long-term, like finding a way to preserve water, oxygen, nitrogen and carbon in the new settlements and finding inexpensive ways to replace rare elements that will inevitably be lost over time, either by importing or by some kind of subsurface mining if the elements we need are there.”

  Chaz highlighted Item Six on his laptop.

  “Once we have items One through Five resolved, we arrive at Item Six- deciding on locations and building human habitations and other facilities. On Earth, Item Six is where colonization starts. That is, we have to decide where to put settlements, and build shelters that make human habitation safe. Compared to our first five issues, Item Six is pretty straightforward. We already have a number of critical criteria by which to decide how to locate a facility. Finding the right places won’t be easy. We still have to come up with structures that are airtight and can either accommodate the temperature swings on the Moon or be protected from them in some way. If we solve the big problems, though, locating and building settlements will be practical. If we don’t take care of the first five items, putting settlements on the Moon for even moderate periods of time, on the order of months, may not be practical.

  “We know what we are looking for in the way of locations, at least to some extent. We probably want nearby caves or canyons to build in, either for complete or partial protection of some of our facilities. There has to be someplace close to build out-in-the open surface stations, at least to collect solar energy and probably for the location of research facilities for various forms of sensors. A broad flat surface may also be needed for launching and landing spacecraft. On the Moon, mixed geography (lunography?) in a relatively small area might have distinct advantages.

  There’s been a lot of speculation about building at the poles because of the possibility of finding water ice in permanently sheltered areas. That’s a possibility. Another possibility is that we will want to build a habitat that gets virtually all of its energy from the sun, which can be done by having solar energy collectors on opposite sides of the poles. That makes things like microwave or cable runs back to the consumers relatively short.

  In fact, there is a big advantage at the poles, where a relatively short connection can be established between the side of the Moon we never see and the side that is always toward Earth. My guess is that there will be any number of activities that will be undertaken on the Moon for which ready access to both sides will be an advantage.

  “The next bullet is Gravity. I chose to put this one near the bottom because at present we have an approach to low gravity survival and our best estimates don’t look too bad, based on what we know of human life in zero gravity. Gravity is a low priority issue for us because we have experience in zero gravity at the International Space Station and on earth via a number of experiments that have been conducted over decades. According to current estimates, visitors to the Moon can stay for up to two years without experiencing irrecoverable physical issues. We don’t want to take chances, though, so I believe that we will set a limit of a year for a stay on the Moon for any given person. That should be enough time for most researchers to get things done. It should also be adequate to allow construction workers and other service personnel to acclimate and be productive for an extended period.

  “This doesn’t mean that we can simply let people go to the Moon without making visitors aware of the issue and providing an approach to living on the Moon that maximizes their chances of recovery from a low gravity environment. That approach is to provide humans with rigorous exercise regimes and set limits on the amount of time that any human stays on the Moon to avoid irreversible damage.

  “Then there are the things we can’t try on Earth, but will be able to do on the Moon. Things like putting people in centrifuges every so often, to see if one gee in a machine makes a difference concerning a body’s tolerance for low gravity. Nonetheless, the first few years are likely to be based on what we already know of zero gravity living- visitors will have to be monitored, people will have to exercise properly, and our time limit should be rigorously enforced.

  “It would be good if we can find a long-term solution to our gravity problem. Can we find a way to enable people to stay for five or ten years without being stuck, so to speak, unable to return to Earth because of changes in their bodies? We will have to do research on this, on the Moon. For the first years of humanity’s stay on the Moon, there will have to be limits.

  “One thing we don’t do much of in zero gravity at present is use machines to do work, rather than people. People are still more versatile than machines in space, but there are things about the lunar environment that might make automation much more cost effective. If nothing else, properly designed machines won’t have to be rotated off-Moon every year.

  “Bottom line is that we have a successful approach to the problem of low gravity. Even though it’s untested in low gravity, it has been tested in a more severe environment- zero gravity. Unless we are missing something pretty big, our experiences with zero gravity should provide a decent guide for survival of humans on the Moon.”

  Chaz highlighted Item Eight on his list. This one blinked off and on, and drew some laughter from the audience. Danny smiled, but he didn’t laugh.

  “Then we have Item Eight- Funding. Putting humans on the Moon for extended stays is going to cost money, especially if the decision is to keep a number of habitats operating on a permanent basis. Clearly this is a problem that is in a class by itself. Our principle backer is shelling out quite a bit of his personal wealth to get our solar sail ships up and running. If we want our ships to have places to go, however, we have to start thinking technologically about how we build successful human habitats someplace other than Earth. To do that, we need to find backers, whether they are private concerns or governments, to help pay our way. In the short run we may be able to establish small habitats using research grants. In the long run, however, we have to find financial or other important reasons to have people live on the Moon. Some form of return on investment will be needed. Perhaps it won’t be necessary in the first couple of years. By year five, however, I think colonization of the Moon will be in trouble if we can’t find something in the way of return on investment that at least gives people hope that living on the Moon can be made to pay for itself.”

  Then he pointed to Item Nine, which also blinked off and on. No one laughed this time.

  “And there we have the last, but not least of our items. Making a Living. Our colonization plan has to have a way for Danny and his backers to get some of their money back. Not all, necessarily, but enough to encourage investors to think that they are getting something for their money. In the short run, like the five-year horizon, investors and contributors of in-kind services will be okay with expanding the horizons of humanity. But sometime around that five-year m
ark, we have to have income streams. Research is one of the likelies, but to many potential investors research is just another money hole. There will be foundations and universities that want space on the Moon, but in the long run that won’t be enough. We need to think now about what the Moon can give us. Or what we can take.”

  Danny walked up to the podium after the meeting. He waited patiently as his foundation director, now science advisor and head of the Moon project, answered some last minute questions. The extra few people noticed who was standing behind them and cleared a path.

  Chaz and he shook hands. “Good show, Chaz. Looks like you touched all the bases.”

  “Thanks. Now all we’ve got to do is find money. Oh, and get to the Moon and build some permanent installations.”

  Danny smiled. “Yeah. That’s what we’re here for.”

  They stood together in silence as the stragglers filed out. Then Danny turned back to Chaz and muttered, “What exactly is going on back there?”

  “Back where?”

  “Back by the coffee. Is our boy hitting on Charity?”

  Chaz glanced toward the back of the room. “Hm. You may be right. And he may not be striking out. Well, isn’t that interesting.” He shrugged, a discreet smile on his face. “Some guys just don’t care about the odds.”

  Danny couldn’t help himself; he laughed. “Guess that’s how we got here. I don’t know whether I should laugh or cry.”

  Chaz turned away from the quiet little scene too. “Wish them luck, and hope his work doesn’t go to hell.”

  **

  The following day, Danny and Chaz were having lunch in Danny’s office. When coffee came out, they settled back to talk about destination issues on the Moon.

  “It sounds like I have to write the solar ships off or we develop a marketing plan to get backers for colonization of the Moon. I guess it would help if our marketing plan actually had a potentially profitable product to sell.”

 

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