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Disclaimer 1: These are my personal opinions. I emphatically do NOT speak for my employer (who probably wishes to remain anonymous--I haven't asked) or for anyone else, real or ficticious, living or long since dead; human, cetacean, or space alien; animal, vegetable, mineral or ethereal.

Disclaimer 2: I have had a professional interest in the space program for my entire 18 year career, but all of my academic training (and work) has been in engineering. My interests in economics, psychology, religion, sociology, and political science are strictly amateur.


Where (In Space) Do We Go From Here? or,
Why Do We Have A
Manned Space Program?

Peter A. Taylor
Summer 2000


In a previous essay, "Why are launch costs so high?" I tried to explain why space launches are so expensive. I expressed my belief that lack of direction is a major obstacle to solving this problem, but I said very little about what can be done about it. In this essay I offer some suggestions. Because I think the problem is largely one of political will, my aim is to build consensus, and thus my intended audience is not a few specific decision makers, but the space futurist community as a whole. Anyone may participate; a voter's registration card is not required. As a side effect of writing this, I also hope to clarify my own thinking about my career.


Here are my suggestions for what we space futurists need to do in order to have a manned space program that's worth cheering for:

  1. Know what we want.
  2. Know how badly we want the various pieces of it.
  3. Have a plan for getting where we want to be.
  4. Present a unified front.

There are too many possible directions for space efforts to go, and too little profit or political support, to allow moving in all of these directions at once. What kind of launch vehicle work should we advocate? A Magnum (Saturn V class) booster for going to Mars? A small "clean sheet of paper" Shuttle II? Liquid fly-back boosters (LFBB) for Shuttle evolution? Subsidies for privately developed launch vehicles? More X-vehicles? Should X-vehicles focus on technology or operations research?

While this work on launch vehicles is going on, should we support ISS? How hard should we be pushing ground-based closed ecological life support system (CELSS) research? What about unmanned space exploration?

It isn't enough to be able to say that a particular project (ie. Mars Direct) is a good thing. We collectively need to be able to negotiate over the details. If there isn't enough political support to fund both Mars Direct and Shuttle II effectively, we need to be able to choose between them wisely. How much extra are we willing to spend in order to send people to Mars instead of just robots? How much extra are we willing to spend in order to send humans to Mars this decade rather than next decade? We need to know this because a human Mars mission probably competes directly with reusable launch vehicle development for funding. Which budget trade-offs are good ones and which aren't?

If I want other space futurists to agree with me, I can't simply state my position regarding what our objective(s) ought to be. I need to lay out a reasonable set of possibilities and defend my choice. This means I have to open The Big Can of Worms:



Why do we have a manned space program?

To put this in perspective, I think back on that night in July of 1969, when I was nine years old. My father was usually very firm about us kids going to bed on time, but on the night of the Apollo 11 landing, he made an exception.

Why did John Taylor let his children stay up late? He was a physics professor at a local community college, and he was very excited about the moon landing, as were my brother and I. I have trouble finding words for this without using religious language. I am reminded of the Promethean allusion in the title of Apollo 11 Command Module pilot Michael Collins' book, Carrying the Fire. It was as if some flaming cosmic torch was handed down that night, and it was important that we all be awake and present to witness it. Or perhaps I should say, to receive it.

In a parallel development, my brother and I were becoming readers of science fiction. We learned to especially like the hard core science fiction of Clarke, Asimov, and Niven, but we also liked the softer stuff, like "classic" Star Trek. Science fiction was and remains today only vaguely definable, blurring imperceptibly from hard science into utter fantasy, in a way that seems to me to echo the muddled sense of purpose of the manned space program.

Why do we read science fiction? William Hartmann's novel, Mars Underground, tries to put some excitement into his Mars exploration scenario by positing an enormous alien artifact (sorry about the spoiler). What does this have to do with a real-life space program? In classic Star Trek, Captain Kirk seemed to be interacting with new and interesting space aliens, the proverbial "priestess of the bronze brassiere," in almost every episode. If we interpret this in a literal way, that the purpose of the manned space program is to have interesting face to face conversations with extraterrestrials, we are forced to my ex-wife's view, that we know enough about this solar system to know that the priestess doesn't live here: wake me up when you invent faster than light travel.

A variation of the "wake me up when..." theme was described to me in terms of the cat that gave Heinlein's novel, The Door into Summer, its name. The cat meows at a succession of doors during winter, trying to command its owner to open the right one, the one that leads into summer. The cat doesn't understand that the time is not right, and it will just have to wait. Similarly, space colonies and the other important things that space futurists want to build will just have to wait; the technology is not ready, and sending humans into space at current launch costs with current life support, power supply, and manufacturing technology is like the cat scratching at the door to make it be summer.



Short and Medium Term Tangible Benefits

Several other commonly heard reasons for having a manned space program have similar problems holding up under close scrutiny. One of the reasons why the NASA Public Affairs Office (PAO) is so ineffective at portraying NASA in a favorable light is that it is forever talking about "spinoffs." As Richard Dawkins put it, "Justifying space exploration because we get non-stick frying pans is like justifying music because it is good exercise for the violinist's right arm." By "spinoffs," I mean using technology that was developed for space in applications that are not directly space-related; I don't consider asteroid mining or solar power satellites as "spinoffs."

The "spinoff" argument for manned space flight is unconvincing for a number of reasons. For one thing, one often hears claims that spending on the manned space program brings economic benefits that are greater than the costs by some ratio, be it 7:1, 14:1, or whatever. Lord Chorley referred to these claims in a "Viewpoint" article in Space Policy, August 1988, "Economics of space and the role of government." He quotes Henry Hertzfeld, former Chief Economist of NASA, "No economic study should attempt to put a 'bottom line' ratio or return on space R&D investments." To do such a study properly would require a universe-jumper, so one could compare the world that is with a hypothetical world without a manned space program. Otherwise, the best one can do is guess, based on, in Lord Chorley's words, "a series of assumptions...which are incapable of being tested and in some cases are intuitively implausible." One study which estimated this ratio to be 8.3 was followed up by another that found it to be indistinguishable from zero. Regarding the latter, Lord Chorley notes, "This result is rarely quoted." The point is that we do not know what the benefit ratio is, and anyone who says he does at best is kidding himself. This doesn't mean that the benefits are zero. We simply don't know what the numbers are.

A second problem with spinoffs as a justification for the manned space program is that the relationship between the sort of program objectives that space futurists are interested in and commercially important terrestrial applications is too tenuous. One sometimes hears claims that the manned space program is needed as a "framework for technology development," but I've never heard anyone seriously try to argue that research that is oriented towards rocket engines is more effective at improving airplane engines than research that is oriented towards airplane engines directly. As Poul Anderson put it in a 1984 lecture, Space: Promises and Problems, "The average man is not dumb; he's perfectly able to see that sending men to the moon is a rather roundabout and expensive way of producing a teflon frying pan, especially considering that teflon was already in existence." There are too many worthy research programs, such as on aircraft icing, that are notoriously underfunded, and too much of the manned space budget goes for repetitive "operations" that have little to do with technology development.

Apart from any questions about whether the importance of the manned space program in promoting commercially important technology has been greatly exaggerated, Earthly spinoffs are simply not that interesting. They were certainly not interesting enough to my father to justify letting his children stay up past our bedtime. This point escapes very few people. The emphasis that manned space advocates put on spinoffs is at best an evasion. The main effect of this emphasis on me is to drive home the point that we lack direction.

One also frequently hears an analogy drawn between the first transatlantic voyage of Christopher Columbus and the current manned space program. The unsatisfactory nature of this analogy was driven home rather brutally by James A. van Allen, of "van Allen belt" fame, in a "Perspective" essay, "Myths and Realities of Space Flight," in the 30 May 1986 issue of Science (pp. 1075-6):

Fervent advocates of the view that it is mankind's manifest destiny to populate space inflict a plethora of false analogies on anyone who contests this belief. At the mere mention of the name of Christopher Columbus they expect the opposition to wither and slink away. I find it possible to resist such an expectation. If reference to Columbus is made in an offhand, thoughtless way, it is merely incompetant; but if made with full knowledge of the facts, it is deceitful and fraudulent.... [T]he surface of Mars has been studied comprehensively by a succession of U.S. and Soviet spacecraft.... If a similar survey of America had been available in the late 15th century, the mission of Columbus' fleet to the West Indies would have been unequivocally desirable. But the application of the Columbus analogy to support advocacy of a manned mission to Mars is massively deceitful. Mars is not terra incognita. We have already explored it and found it to be far more desolate and sterile than the heart of the Sahara desert. There, of course, remain many matters of deep scientific interest on Mars but these matters can be addressed ... by automated ... missions."

The point of the Columbus analogy seems to be that it is unreasonable to demand a convincing "business plan" from someone who proposes a low-cost voyage into terra incognita, land that is genuinely unknown. A cavalier attitude about a business plan is appropriate under those circumstances. But as van Allen points out, we know too much about our solar system for this analogy to hold, and there are cheaper ways of aquiring the information we don't have. Perhaps 30 years ago we could with integrity have gotten away with such a cavalier attitude, but not any more. We know too much. We need a credible business plan.

My father's response to the question, "Why do we have a manned space program?" was similar to the Columbus analogy. He repeated a retort that Michael Faraday (quoting Benjamin Franklin, I'm told) had reportedly given someone who asked what the dynamo, his newly invented electric generator, was good for: "What good is a newborn baby?" This answer, while rhetorically satisfying, has the same problem that the Columbus analogy has: it may have been a reasonable reply at one time, but we know too much about the environment we're working in, and are spending too much money, for our lack of direction to be excusable now. We also know too much about babies for this answer to really be as clever as it sounded in the first place.

Van Allan brought up the phrase, "manifest destiny," which I have also heard elsewhere in this context, so I will address it directly. Claiming that we should build space colonies because it is our "manifest destiny" to do so is an example of the fallacy of "begging the question" (aka petitio principii). The problem with this class of argument is that the premise is only cogent for people who already believe the conclusion anyway, like arguing that the Pope is going to Heaven because he's Catholic, and all Catholics are going to Heaven. It is possible to take the "door into summer" view, and agree with van Allen for the forseeable future, but still accept the manifest destiny claim in the long run. In this case, manifest destiny still doesn't tell us how much we should be spending on manned space in the forseeable future, or how we should spend it.



Philosophical Note on Uncertainty

Because of the uncertain nature of the payoffs of the exploration business, proposals for exploration put us in the realm of what Industrial Engineering textbooks call either "decision making under risk" or "decision making under uncertainty," depending on whether we have information about the probabilities of various outcomes. Uncertainty does not put us on any sort of elevated philosophical plane where we are exempted from having to say anything intelligent about expected benefits and costs to the people whom we are asking for money. Decisions about exploration may involve a lot of guesswork and judgement, but there are no blank checks here. Ignorance is not bliss.

If we try to sidestep the guesswork by claiming to be on an elevated philosophical plane, exempt from criticism by "bean counters," or by saying that exploration is a Good Thing, and should be funded at some arbitrarily high level simply because it is a Good Thing, we run into several problems. First of all, saying X is good doesn't tell me it is better than Y. Second, the conclusion that I should get a blank check is absurd enough to prevent the argument from being taken seriously. Third, the argument proves too much. It can be used to justify almost anything, any of a hundred conflicting uses of the public's money. The decision makers we hope to influence couldn't use this as a basis for making a decision even if they wanted to. Finally, as I suggested with regard to manifest destiny, apart from its ineffectiveness at swaying decision makers, it also fails us in terms of providing guidance in setting our own goals and priorities.



Scientific Benefits

Occasionally one hears the claim that humans are better than robots at exploration because they can respond better to the unexpected. Is that why we send humans into space? Because it is the most cost-effective way we can think of to aquire scientific data? My first reaction is that at current prices, humans can only compete with robots in situations where the schedule is very tight and money is very loose, and even then it is highly dubious. It's true that humans are better able to respond to surprises than robots, but it isn't reasonable to compare one expensive crewed mission to one cheap robotic mission unless we are in a terrible hurry and there isn't time to send a followup mission. If we took the amount of money necessary to send humans to Mars, and put it in the bank, we could send robotic missions every three years until the end of time. Perhaps there are economies of scale in the space exploration business such that at some level of activity humans become competitive with robots, but at current NASA funding levels, this speculation seems rather academic. I want to send people to Mars in spite of their scientific cost-effectiveness, not because of it. But I don't want human tourists on Mars infinitely badly--the price has to be right. As with the Apollo program, science is part, but only part, of the motivation.

Another claim is that we need humans in space to do certain kinds of research efficiently, particularly research on humans. This is somewhat circular logic, because most of the reason for doing research on humans in space is in order to support the manned space program. As with the Columbus analogy, we already know too much about humans in space from Skylab and Mir to be able to plead ignorance about what we hope to accomplish by studying it further. In addition, the level of funding for research that requires humans in space is too low in comparison to the cost of the manned space program to make sense as a justification for it. This is also true of materials processing experiments, in so far as these benefit from human presence.



A Belated Organizational Note

Up to this point, I have made little attempt to group the arguments for a manned space program that I have discussed into orderly categories, other than that so far they have all been what I consider to be bad ones. One obvious category is scientific arguments, which I think for the forseeable future are unable to stand in the face of competition from robots, and about which I have little else to say. A second class of arguments attempts to pursue more tangible benefits that are available in the short and medium term. This includes spinoffs and tourism in the short term, and asteroid mining and solar power satellites in the medium term. It also includes the Columbus analogy, which claims medium term benefits are probably there, but we don't know what they are. By "short term" I mean roughly within my lifetime, and by "medium term" I mean a few generations. The short and medium term tangibles include military as well as economic benefits, and for convenience I will lump political reasons, such as the historical reasons for the Apollo program, in with military reasons. Like Apollo, which was described by a coworker as "a technical solution to a political problem," the actual reasons for the current International Space Station (ISS) are mainly political. What I particularly want to separate from the other short and medium term reasons are a set of intangible reasons that for lack of a better word I will describe as "cultural." These form my third category, and are the hardest to articulate. Finally, we have arguments involving the long term survival of our species. For convenience, I will lump defense against small "city-buster" asteroids in with defense against planet-killers, but mainly in this final category I want to consider things that threaten species survival. This list of argument types is not exhaustive. For example, it does not include long term economic benefits such as might be enjoyed by people a thousand years from now. However, I do not think these are helpful in justifying a manned space program in the near term, and in any case I would for convenience lump them in with shorter term economic benefits.

So far I have focused on commonly heard, bad reasons for supporting a manned space program. My main emphasis in what follows will be on cultural and species survival reasons, but I still need to tie up a few loose ends.



Short and Medium Term Tangible Benefits, Continued

One of these loose ends is space tourism. If I can some day afford to experience space flight myself, I would want to, but the difference between people enjoying space tourism and enjoying other luxuries doesn't justify spending very much of the taxpayers' money. I see little role for the government here. (I am assuming that the knowledge of how to build cheap, safe spacecraft is largely a public good, and therefore governments would have a legitimate reason for going out of their way to support a fledgling space industry if it were sufficiently beneficial, even if it was producing fairly pure private goods such as joyrides or commodity metals.)

Another argument is that there are natural resources elsewhere in the solar system that are likely to be valuable enough to justify the cost of the manned space program in the near term. One of these is solar power, as collected by large satellites (SPS) and delivered to Earth by microwave transmissions. The satellites are usually envisioned as made from lunar materials. Another candidate is metals mined from asteroids, or possibly a helium isotope (He3) recovered from lunar soil that might some day be useful in nuclear fusion reactors on Earth. I take the SPS argument as potentially serious, but not compelling. If I had to make a decision today about how to deal with our dependence on fossil fuels, I would choose nuclear power over SPS. I don't find the He3 argument very helpful because it is too speculative to justify an interesting manned space program in the near future. I also see little basis for hope that asteroid mining will be able to compete with terrestrial mining and recycling with any propulsion system in the forseeable future. A possible exception would be if environmental concerns were to some day make terrestrial mining extremely expensive. This is a better argument than He3, but it is still too speculative to justify an interesting manned space program in the near future. This is true of "put polluting industries in space" arguments in general--scrubbers are almost always cheaper. Some kinds of biological research could some day be candidates for moving off-Earth, but the practicality of this is again very speculative. Materials processing on a commercial basis, taking advantage of vacuum and weightlessness, is similarly speculative, its economic viability depending strongly on launch costs.

One reason why Europeans immigrated to the Americas was population pressure, with cheap arable land being available in the New World. The hope that our off-Earth transportation and life-support capabilities will be great enough in the forseeable future to provide noticable relief of population pressure for the Earth is pure fantasy. A different argument is that a New World would provide a wonderful opportunity for those few who are fortunate enough to get there, that they would be much better off than those left behind. If something utterly dreadful happens to the Earth, this may be true, a point to which I will return. Otherwise, I dismiss this argument with the observation that no life support capabilities that we will have in the forseeable future can hope to make life off-Earth nearly as pleasant as the same amount of wealth could make someone's life on Earth.

One motive for a manned space program that might provide a legitimate role for government is to separate warring factions. The Mormons moved to Utah to avoid religious persecution. Criminals from the Old World were often exiled ("transportated") to the New World (Heinlein's novel, The Moon is a Harsh Mistress, borrows this theme). Poul Anderson's New America suggests an interstellar colony might be supported in order to get rid of a troublesome political minority. Quite a bit of science fiction plays on various people's anti-government sentiments, but if we are asking the government for money to make our dreams come true, it is a bit awkward to explain that our dreams involve escaping from the government's evil grasp. I myself happen to be one of the more vulnerable people to this sort of appeal, but realistically, if we want to solve political science problems, we should really be studying political science, not rocket science. I dismiss these arguments as well as being too speculative to justify serious funding of the manned space program. If and when our "door into summer" opens, I will not be surprised if religion plays a major role in motivating many of the early settlers, but for the forseeable future, the Earth is not likely to be so terribly homogenized and overpopulated as to make this a compelling reason to leave the planet.

I have described a number of the above arguments as "speculative." This doesn't mean that those arguments are completely worthless. What it does mean is that they have relatively narrow limitations. If we try to push these arguments too hard, they will break. For example, the argument that we should pursue solar power satellites (SPS) may be a good reason for doing paper studies and some ground-based materials processing experiments. It can also be used, along with several other arguments, to justify playing with a series of frankly experimental vehicles to try to get launch costs down, because the feasibility of SPS is sensitive to launch costs. It can't be used to justify an expensive space station devoted to working out the technical details of a project to which we are not yet committed.



Cultural Benefits

I next come to a category of arguments I am calling "cultural." I don't know how to separate culture, spirituality, depth psychology, and religion. In depth psychology terms, there is something archetypal about space, or "the heavens." An instructor at the local C. G. Jung Center said that "great dreams" commonly feature such symbols as God, the Virgin Mary, the ocean, and space. There is something about space that, for many of us, floats our boats in ways that are non-rational and very hard to articulate. The phrase, "pure unadulterated vastness," comes to mind. There is an excellant book by Robert Bly called A Little Book on the Human Shadow that offers some suggestion of what might be going on. Bly uses the metaphors of the projection screen and a long sack that people drag behind them. The sack is filled with parts of their personalities that they don't recognize in themselves, but often project onto other people or things, which is what the projection screen is about. It may be that part of the fascination of science fiction is that its "other worldly" nature invites us to examine ourselves with particularly strong light. Certainly "classic" Star Trek often had obvious psychological themes, and part of what seems so flat for me about Next Generation is that it seems more interested in taking a utopian technological advocacy role than in using space travel as a pretext for exploring the human condition. Is the manned space program to some extent an exercise in psychodrama? If so, does that provide some basis for a role for the government, as some sort of public mental health program? I suspect that the answers are respectively yes and no. I can see some similarity between a modern manned space program and building cathedrals in medieval times, as deep expressions of who we are, but I shudder at the thought of trying to run NASA off of the budget for the National Endowment for the Arts. I think a reasonable reply to such a suggestion is that there are cheaper ways of doing psychodrama, and that perhaps we're just not reading enough Niven.

There are several questions about our culture that I think are relevant here. Why do we read science fiction? Why do children (and adults) build plastic models of the Starship Enterprise, or little Estes solid rocket powered flying models of Saturn Vs? How is this relevant to the government's role in manned space flight? For that matter, why do governments build monuments? Part of the answer to why I read science fiction is escapism. I am reminded of part of a recent sermon by Rev. Robert L. Schaibly about the movie, American Beauty:

The confusing role fantasy plays in our individual lives is a theme. When we are unhappy with our lives we try to visualize something else, and the line between that and fantasy is often indistinguishable. What to be when we grow up. A high school senior may have a vision about athletic achievement or work that requires eight more years of education, but in general the same idea in a 65 year old person is a fantasy. Yet where do we get our ideas, but through daydreams?

Historically, my interest in space travel in science fiction has not been so much that I thought it would be cool to visit alien worlds as that I thought it would be cool to leave this one. I tend to get through difficult times by maintaining a very active fantasy life. As I think about my escapism and reflect on why people build toy models, I am reminded of David Friedman's explanation of why people buy lottery tickets. The State of Texas, like several others, sells lottery tickets with rather bad odds (and makes its competition illegal). Buying lottery tickets makes very little sense as an investment, and it's hard to argue that people buy them because they like risk when the same people also buy insurance. But people like to fantasize about being rich, and the lottery tickets make the fantasies seem more believable. Perhaps the manned space program serves a similar function, making people's futures seem more full of opportunity, even though, for the forseeable future, many of the the actual claims made for the manned space program seem rather far-fetched.

Part of my reaction to the Apollo landing was simply one of awe and wonder. Part of this feeling was because travelling to the moon was so far out of line with what people were used to thinking of as being possible in any practical sense. That sort of experience will be very hard to repeat. But there is also something deeper, a sense of a small child from the city seeing a cow for the first time and asking his mother, "Why?" I find it hard to describe without religious language. I remember a coworker who will tell you he's a Christian if you ask him what religion he is, but if you really want to see him get excited, you need to get him talking about sending people to Mars. I am reminded of the last line of John Gillespie McGee's poem, "High Flight," "I reach out my hand and touch the face of God." The experience of watching transmissions from robotic space probes is different somehow.

Earlier I suggested that some sort of cosmic torch was handed down during the Apollo 11 landing, and that my brother and I had to be awake in order to participate in the ceremony. It seemed as if the entire species was collectively having its Bar Mitzvah. We were coming of age in the Milky Way. In Konstantin Tsiolkovsky's language, Earth was the cradle of mankind, and the baby had just taken its first step. Arthur C. Clarke captured some of this feeling with the title of his novel, Childhood's End. The closest thing to an individual coming of age ceremony I had was getting a driver's license. The Apollo landing felt as if our species had gone to God's version of the Department of Motor Vehicles, taken the test, and passed. We have the license now, and it holds the promise that we will some day be able to accomplish great things, but we're still living with our parents, and will be for the forseeable future.

I have no intention of trying to equate science and religion, but these two areas of thought do tend to get in one another's way from time to time. This is something that I think my father was quite sensitive about, as am I. Episcopal Bishop John Spong and his wife, Carolyn Spong, have described this in terms of "premodern" versus "modern" and "late modern" or "postmodern" thinking. Part of what was going on during the Apollo 11 landing was a triumph of a modern worldview over a premodern one. A cosmonaut had made a big point of reporting not having seen any angels in Earth orbit. Frank Borman had read from the Bible during his Apollo 8 flight around the moon. I don't know exactly what Borman's point was. Spong's point was to keep Christianity as a body of spiritual teaching, while discarding the Bible as a source of literal scientific or historical factual information. Whatever conclusion one draws about the value of Christianity as spiritual teachings, it was quite clear that the understanding of orbital mechanics that sent Borman around the moon came from Copernicus and Newton, not from the Bible. Since the literal-minded reading and acceptance of the Bible is still very much of a live issue in the modern US ("scientific" creationism, anyone?), I welcome opportunities to drive nails into the coffin of "premodern thinking." I also see value in a manned Mars mission from this standpoint, and while I would hesitate to ask Congress for money for the purpose of embarassing religious fundamentalists, I would support a "flags and footprints" mission if the price were right.

One of the benefits of the space program was the "Spaceship Earth" paradigm shift, from seeing the Earth as huge and rugged to small and delicate. This was partly due to photographs that could just as easily have been taken by robots as humans, but the "spaceship" idea probably would not have caught on nearly as well if we did not sometimes have people on board our spacecraft. Perhaps some important new ways of thinking will result from long duration human space flight or from trying to survive on Mars, however briefly on our early attempts. That's worth something, and could help partially justify manned space missions, providing they were reasonably novel. But again, if we were to ask Congress for money on that basis, we might reasonably be told that there are cheaper ways to change our thought patterns: perhaps we should take up meditation, study philosophy, or read more science fiction.

One way of looking at the manned space program is as entertainment. David Friedman called it "The Greatest Show Off Earth." John Young referred to "the adventure of human space exploration." From this standpoint, as one of my coworkers put it, asking why we put humans on spacecraft is like asking why we have jockeys at horse races. Horses can run without jockeys, but it's not as much fun to watch.

It is also said that there are psychological advantages of having a frontier. I could argue either way on this one as far as psychology is concerned. Also, if I took this argument seriously, I'm not sure what conclusions I could draw from it about what would be an appropriate funding level and how the money should be spent. There is a respectable argument (Mancur Olson, The Rise and Decline of Nations) that a frontier is helpful from an economics standpoint, in tending to destabilize cartels and price-fixing agreements. This argument might be marginally helpful if we were close to being able to build an economically viable space colony, but it doesn't seem helpful in the near term.

Another obvious reason for the manned space program is national prestige. From this standpoint, a nation having a manned space program is like a wealthy family owning an expensive sports car. This makes the US manned space program look like the Soviet Union's efforts to do well in the Olympic games. Prestige or national pride seems to be the main thing keeping the Mir space station flying. An odd thing about this is that the news articles I've seen keep quoting Russian officials who insist that the Mir is vital for technical reasons, and that prestige is merely incidental. It seems to me that much of the prestige associated with the space program comes from people thinking that its purpose is far greater and nobler than just showing off. This may not have been true in the Apollo days, when there was such a huge amount of awe and shock that such things were possible, but now that manned space flight is old hat, showing off just to show off isn't cool anymore. The prestige seems to depend on a belief that prestige is a secondary motive (I call this Frank's Paradox). As a reason for the US space program, prestige seems to be a minor issue. (We're not as screwed up as Russia.)

(Update, 8-25-2007: I've changed my mind about the importance of prestige to the US manned space program. I now believe it is of central importance. See the above link regarding Frank's Paradox. Bryan Caplan described Sputnik as an "economically insignificant prestige project," and I'm afraid there's a lot of this going around.)

It may seem odd that I have chosen to lump "political" reasons in with the "short and medium term tangible" reasons, but "prestige" is in with "cultural" reasons. This is rather arbitrary, as I am hard pressed to explain the difference. I think of prestige as a consumer good, something that people value directly, whereas "political objectives" sound to me more like an "investment" of sorts, a means to some other end. An example of a fairly tangible political objective is using the International Space Station to prop up the Russian aerospace industry so they don't sell missiles to Iran. Prestige seems too intangible. In the case of the Apollo program, the distinction is very unclear to me. Did JFK support Apollo because he thought it was cool, or because he thought other people thought it was cool? Was it to influence the behavior of other countries by convincing them that the US was not lagging the USSR in ballistic missile technology, or to comfort US citizens by providing something akin to the "intangible religious benefits" that the Internal Revenue Service uses to judge whether contributions to a church are tax deductable? I'm not sure I can tell the difference, or that it matters.

Finally among cultural reasons for the manned space program, we come to the worship of technology. Shortly after the Challenger accident, there were suggestions in the popular press to scrap the Shuttle and try to build a new, Single Stage To Orbit (SSTO), fully reusable launch vehicle, something that would be enormously difficult to do. As a coworker put it, some people have a strange attitude towards technology--a reusable SSTO would be much harder to get to work than two-stage, and we can't even get a two-stage to work properly. As I argue in the companion to this essay, "Why are launch costs so high?" efforts to lower space launch costs have consistently been much too focused on "advanced" technology, to the great detriment of these efforts. I think this is related to the belief some people have that living on Mars would be more attractive than living on Earth. A future in space requires high tech, and life on Earth doesn't, so when we think we are comparing living on Mars with living on Earth, we tend to inadvertently compare high tech with low tech, and so we make silly comparisons. A popular attitude among space futurists seems to be that advanced technology is good, and the manned space program is the One True Path to advanced technology. I object to this not only because I see other paths, but because I share Sam Keen's concern that technology has been allowed to grow in undisciplined ways. Our ability to build weapons of mass destruction and exploit natural resources has outstripped our understanding of psychology, ecology, political science, and other "soft" sciences. From this standpoint, a Mars colony is yet another attempt to find a technological solution to a political problem.

I leave my list of "cultural" reasons for a manned space program now on a religious note. As Michael Meade put it, the world is being shaken by a sort of mythological earthquake; the old myths are crumbling, and no one knows what the new myths will be that will inform our perceptions of the world in the future. I do think that in some sense, an excessive interest in space travel is a religion. Specifically, it's my religion, or at least one of them. It floats my boat. I didn't choose for this to happen--I feel more as if it chose me. It's non-rational. Like Elaine Pagels, who reflected on her feelings towards Christianity in Adam, Eve, and the Serpent, I find the symbolism of this religion moving, regardless of what I think of the theology. Furthermore, my purpose in this essay is similar to Bishop John Spong's purpose in Why Christianity Must Change or Die. I want to create a new theology of space travel that I can support without suspending my critical thinking skills.



Species Survival

I now come to arguments involving the survival of our species. As Apollo 16 astronaut John W. Young wrote, "NASA is not about the 'Adventure of Human Space Exploration,' we are in the deadly serious business of saving the species." The cultural reasons may be the main factors affecting the thinking of space futurists, but arguments involving survival have far broader appeal and can be used to justify much larger expenditures. If we think of the space program as a safari, it is a very expensive safari, and if we're going to justify the cost in terms of the meat we take, we need to bring back an elephant, not a jackrabbit.

An obvious near term objective is defense against Earth-crossing asteroids and comets. As Carl Sagen said, the reason dinosaurs are extinct is because they didn't have a space program. This seems to me to be a compelling reason for ground-based and perhaps some unmanned space-based sky searches (Spaceguard). Asteroids are in a different class from comets because they can be detected relatively easily decades in advance, and once detected, are relatively easy to reach, and are close enough that unmanned spacecraft near them need relatively little autonomy. Comets are a much harder problem, and more likely to directly require humans. Paper studies would certainly seem in order, and perhaps development of a nuclear thermal or other high performance propulsion system, which would be very useful for other missions. But the role that a determined asteroid defense would provide for humans in space in the near term is very limited.

John Young's essay on "Mitigating Earth Disasters" is oriented more towards using technology developed for the manned space program in order to cope with terrestrial natural disasters such as very large ash-producing volcanos and climate changes due to variations in the sun's output. Excluding comet and asteroid defense, the argument as he presents it is basically one of spinoffs, and is vulnerable to the same counterarguments discussed earlier. If my ultimate purpose is to develop electric power supply, hothouse, and cold weather survival technology for terrestrial use on a massive scale, why should I be fooling with rockets, vaccuum systems, and artificial gravity? I certainly don't mind taking terrestrial technology developed for the medium term and spinning it off into space applications that can take people to Mars, but the justification for going to Mars is left to fend for itself, and we are back to the "door into summer" position of waiting for somebody else's technology to ripen before we can go out and play. In order to justify space research and technology as being dual-purpose, it needs to really have important dual purposes. It would also be a lot easier to justify doing such dual-use R&D if the catastrophies involved were man-made, which seem more likely to threaten a significant fraction of the Earth's population than the purely natural ones. Fortunately, there is at least one area of research which I think fits the bill: closed ecological life support systems (CELES), which are necessary for any long term human presence in space, and which require a sophisticated knowledge of ecological systems which we desperately need to understand and limit the effects our industrial civilization is having on the Earth's biosphere. Complex closed ecologies are needed to understand how ecological systems work so we know how to solve the problems we are creating and to prove that we understand them so that we can mobilize the political will to deal with them. Even if the rest of NASA were abolished, I would still want the CELES work in the Bioplex facility at Johnson Space Center to continue and to be funded aggressively.

Other species survival arguments involve getting some of our "eggs" out of this one terrestrial "basket." In the medium term, an alternative basket might consist of an enclosed colony either in free fall or on another celestial body. In the longer term, this might involve terraforming Mars. In the very long term, geological time, the Sun will leave the stellar main sequence in about 1 billion years, and we will want interstellar travel long before then. This last deadline is so far beyond any human time scale that survival considerations of this sort seem to be largely religious again. Although I shrink from describing it as immortality for our species or its distant descendants, it would be a life extension of cosmic proportions for Gaia's children. In any case, a deadline of 1 billion years is too far away to get worked up about, or to allow rational planning if we did somehow manage to get worked up about it. The threats I am concerned with are relatively near term, and are mainly ecological and military, such as biological warfare. Once again we find the manned space program being advocated as a source of technical solutions to what are mainly political problems.

If we wait long enough, and are lucky enough to avoid any major disasters, we will eventually have the technology to build space colonies without government assistance, just as a side effect of the general progress of science and technology. The reason for government involvement from a survival standpoint is because we are concerned that disaster might strike before we would otherwise be ready. In formal terms, the survival argument for the manned space program would sound like this: "If we push space technology hard, with $X, we will be able to build a permanent colony Y years sooner than we otherwise would, enabling the species to survive a medium-term catastrophe that has P probability of taking place within that time frame." If the numbers, X, Y, and P, make sense, this could justify a large program.

The catch is that we have to have a permanent, quasi-independent colony at the end of the program. "Permanent quasi-independent" means that (1) under normal circumstances, it has to be economically viable in the face of competition from Earth and (2) in an unexpected emergency, it has to be capable of surviving indefinitely, independently of Earth. A colony doesn't have to pay back any of its "sunk" development or construction costs or pay any kind of a return on investment in any conventional sense in order to be "economically viable," but it has to be able to pay its operating costs. It needs to be attractive enough compared to Earth that sane people will want to raise their children there, and if this requires luxuries supplied from Earth, they have to be paid for without being a significant drain on the sponsoring political unit. (This requires low transportation costs even after the colony is completed.) If the colony is going to be abandoned the first time the political winds shift, it should not be thought of as "permanent." It might become possible to build a colony on Mars that meets the emergency survival requirement long before it is possible to build one that meets the normal competition requirement. Making Mars an attractive place for people to live without continuing subsidies from Earth may require terraforming. My guess is that either of these requirements by itself implies so much self-sufficiency that the difference between them is minor, but that this degree of self-sufficiency will be very hard to acheive, and will require low launch costs, a huge amount of tools and other material goods, and a large commercial space infrastructure that will take advantage of economies of scale, make serendipitious discoveries, and generally push us along the relevant learning curves.



aotv rendering

An Aerobraking Orbit Transfer Vehicle (AOTV) Concept

The payload is depicted in magenta, engines in yellow, oxygen tank in light green, hydrogen tanks in dark green, heat shield in red, and other structure in various shades of blue.



If it sounds like I'm grinding an axe, I am: launch costs influence the rate at which progress is made in reducing the other costs of space activities. For example, consider an aerobraking orbit transfer vehicle (AOTV), a reusable upper stage or "space tug" designed to carry cargo from low Earth orbit (LEO) to geosynchronous (GEO). It may seem obvious that a reusable AOTV would save money in the long term, but in fact, this depends on the cost of propellants in LEO. A reusable has to make a round trip, whereas an expendable's trip is one-way. (See "Design Study of an Integrated Aerobraking Orbit Transfer Vehicle," NASA Technical Memorandum 58264, March 1985.) Even with aerobraking on the return trip, this means more delta-V, 20350 vs. 14050 ft/sec (p. 13), and more weight. The aerobrake alone was to weigh 1855 lb (p. 16), on an 11094 lb vehicle (p. 16) sized for a 28000 lb payload (p. 10), the weight of about three typical GEO satellites. The NASA report assumes a specific impulse of 460 sec. with 1% degradation, and flight performance reserves of 2% of delta-V (p. 13). Using these numbers and the rocket equation (32.174 ft/s^2 to convert from lb mass to lb force), I calculate an additional 5794 lb of propellant attributable to the aerobrake, 1855*(exp(20350*1.02/(460*.99*32.174))-1). Bear in mind that airplanes typically cost between $150 and $300/lb. (Aircraft Design: A Conceptual Approach, 1992, Daniel P. Raymer), whereas mass delivered in LEO costs on the order of $5000/lb. At $5000/lb, that extra propellant associated with the heat shield is worth about $29 million. If an expendable upper stage can be built for a few tens of millions of dollars, and saves several thousand pounds off the gross weight of a reusable AOTV, at current launch costs, the reusable will not be able to save money.

I don't have any particular ideas on how to estimate the cost and schedule involved in building space colonies, or the likelihood of disaster striking the Earth in the mean time, but some of the major technical objectives of such a development program are obvious. In fact, it may be more helpful to organize arguments for the manned space program not by their objectives (ie. cultural vs. economic), but according to the kinds of technological or economic changes they are sensitive to. For example, a Poul Anderson New America scenario requires fusion drive and suspended animation. Permanent colonies require advanced life support or terraforming. All of the arguments I'm interested in are sensitive to space launch costs, including "cultural" arguments, which may be able to justify an inexpensive human Mars mission, but not an expensive one. Nuclear power also seems to be a practical necessity for lunar and planetary surface operations and trips outside the inner solar system. The ability to process extraterrestrial materials, In-Situ Resource Utilization (ISRU), is needed in a wide variety of different forms by all of the more interesting scenarios. Several of these scenarios also involve a lot of unmanned space activity. An economically rational space program would have a much stronger emphasis on teleoperators, long operational lifetimes for space hardware, and greater spacecraft autonomy. For the more interesting scenarios there are issues involving international law that have to be worked out as well.



Building Consensus

My conclusion is that the reason we have a manned space program that is currently active in flying humans in space is mainly a combination of political and cultural reasons, some of which are based on misunderstandings. Species survival and economic benefits are likely to provide compelling reasons for human spaceflight some time in the future, but they are very hard to relate to any human space operations of which we are presently capable.

Which of these objectives make sense? The science that is done as part of manned spaceflight is worth doing on an opportunistic basis, but can not justify more than a fraction of the total cost of the manned space program. Cultural reasons are important. C. S. Lewis expressed a view in his poem, "Science-Fiction Cradlesong," that "Outer space is a concept, not a place...There's no way into the sky." In this view, the cultural reasons are only misunderstandings. I don't think this is true, any more than I think that the fact that I like chocolate is a misunderstanding of nutrition. However, I can't reasonably expect everyone else to share my tastes, and I regard these "cultural" reasons as luxuries, something that I want to buy in quantities that depend strongly on their novelty and their price. So even if cultural reasons were the only reasons for a manned space program, I would still want to invest much of its budget in bringing costs down.

The economics problems associated with resource exploitation and with building colonies are too closely related to one another for me to be able to usefully distinguish between them. Again, species survival will provide a compelling reason for human spaceflight some day, but not with our current technology and economic situation. A case could be made that the needed technology is so far removed from what we have that the "door into summer" view is correct, and that the best thing we can do is forget about human space travel until wealth and technology that is not developed for directly space-related reasons alters our situation dramatically. This would mean not only the moratorium on manned space flight that James van Allen recommended, but also a view that it is a waste of money to develop technology that is not going to be useful within the time horizon within which we can plan effectively. I don't share this view either. Some of the sort of technology we will need for economical manned operations in space, such as cheap boosters, does not appear likely to come about any time soon as a side effect of non-space development, and the lack of cheap boosters is largely what determines the limits of our ability to make meaningful plans. I don't think a serious effort to build cheap boosters needs to be much more expensive than what would be justified by saving money on unmanned launches. A moratorium on manned space flight would result in a loss of "corporate knowledge" that would be hard to regain, and much of the technology that I hope to see developed soon will require test flights and evaluations by human operators.

The manned space program I advocate is mainly focused on development work to enable the economical exploitation of space, with some occasional manned flights for cultural reasons and development testing. From this perspective, I see the Shuttle as a necessary evil, an expensive trainer that we will have to live with until we get something cheaper. Manned Mars missions and the current International Space Station (ISS) are expensive diversions. Regardless of whether we envision our long term objectives as emphasizing cultural, economic, survival, or for that matter, scientific objectives, our primary short term objective needs to be reducing launch costs. Our secondary short term objectives should be closed ecological life support systems, headache-free electric power supplies, and in-situ resource utilization (ISRU). But work on these secondary objectives may not pay off in a visible way for a long time.

How much money it is reasonable to spend on this sort of space program is a judgement call, but one consideration that should limit how hard governments push economically oriented space development work is not wanting to get too far "ahead" of commercial practice. This means a return to a NACA model of the relationship between the public and private sectors (NASA's predecessor, the National Advisory Committee on Aeronautics). Work that is too "advanced" risks not only being wasteful because of the timing being inappropriate, but also risks being permanently misdirected. But we can not go very far wrong if we succeed in cutting launch costs. The "cultural" payoff will be immediate, and it will have long reaching effects in changing the way we think about and execute space missions.



I return now to my suggestions for what space futurists should do in order to have a manned space program worth cheering for:

  1. Know what we want.
  2. Know how badly we want the various pieces of it.
  3. Have a plan for getting where we want to be.
  4. Present a unified front.

What I want is mainly to see progress towards permanent space colonies. I would also like to see manned missions beyond Earth orbit, but unless they are clearly related to a serious effort at colonization, I regard these as a "lark." My plan for getting there is mainly to work on cheaper launch vehicles, with additional work on closed ecological life support, space nuclear power, and in-situ resource utilization. Specifically, for reasons which I described in the companion launch costs essay, I suggest a series of reusable X-vehicles oriented towards operations research rather than reducing weight or improving technical performance. I don't think we're smart enough to build Shuttle II yet. I have nothing to say about presenting a united front other than to thank you for reading this essay.

I do, however, have some more thoughts on having a plan for getting there. One is that we collectively need to resist getting too excited about the "advanced technology" side of launch vehicles, lest we end up with more expensive diversions like the X-33. Since most of us seem to be ardent technophiles, a corollary of this is that if someone makes a proposal that we really, really like, we should be very suspicious of it. We also need to be realistic about the roles of the public and private sectors. The goods that we want to see produced are a mixture of public and private goods. Delivering specific products for specific customers is a private good, which we may expect the private sector to do more efficiently than the public sector, but there is a considerable amount of public good associated with knowledge, which we should not expect the private sector to be terribly efficient at producing. Cultural objectives and species survival are both mainly public goods, as is much of the operations research information needed by private companies to build cheap launch vehicles and in many cases to take advantage of them. The market for the sort of manned space missions which we are interested in developing seems likely to be a government monopsony (only one major buyer) for a long time. The government can "outsource" the launch capability it needs, but this is not the same thing as true privatization. We should not expect a government monopsony to act like a competitive market.

I have two more suggestions to offer based on arguments from The New Science of Economics, by Richard McKenzie and Gordon Tullock regarding competition and duplication of services within government, and from Infinite In All Directions by Freeman Dyson. Just as competition enables private sector customers to get lower prices, McKenzie and Tullock argue that an important factor in keeping the government's costs down is having several agencies that can compete with one another for the same public service fiefdom. Such "duplication of services" is usually the first thing that is condemned by commissions that investigate government "waste," and so these authors argue that the first thing to do to make government more efficient is to abolish all the commissions that purport to be investigating how to do it. My point in bringing this up is to suggest that the various NASA centers should be encouraged to compete with one another at such tasks as developing X-vehicles, rather than trying to "eliminate duplication." I would like to see several NASA centers playing with reusable sounding rockets similar to the ones that are intended for the "X-Prize."

My second suggestion is to follow Dyson's advice, and avoid projects that will take longer than five years or cost more than $100 million or so. The rationale for this is that large, slow projects tend to become overly political, are harder to manage efficiently, and tend to pursue objectives that become outdated before the project is completed. Much of what went wrong with the X-33 may have been related to the size of its budget.

Finally, I want to pound my shoe on the table a little bit more about launch costs. As I suggested earlier, it's as if we passed God's driver's test three decades ago, but we're still living with our parents. I grew up in the post-Apollo days, expecting a permanent Lunar settlement any year now for many years. The reason we don't have one is primarily because of economics. Technology is certainly a factor, but technology is important largely because it drives some of the economic considerations. Even here, economics largely determines the directions in which technology development takes place, particularly in a market economy such as the US.

With apologies to pop psychologist Anne Wilson Schaef, the relationship between economics and technology in the future of humans in space is analogous to the relationship between egg and sperm respectively in conceiving a child. When appropriate sperm comes together with an egg, interesting things happen. If the egg is not present, the process of releasing sperm may look and feel like the process of conceiving a child, but nine months later, you don't get a baby. The egg (economics) is not a means of enabling the sperm (technology) to travel farther and faster towards its goal. From the sperms' standpoint, the egg is the goal.



Although I am interested in advances in other areas, I regard launch costs as a "make it or break it" issue, the most salient portion of the economics problem associated with the conquest of space. Launch costs are the primary economic "choke point" for the entire spectrum of possible human activities in space. If we solve the launch cost problem, private industry will eventually build the rest of the infrastructure we want. If we don't, no amount of government subsidy will produce permanent self-sufficient settlements. If we want a manned space program that brings us more than "intangible religious benefits," we need to get serious about reducing launch costs.



Suggested reading:
James van Allen, "Myths and Realities of Space Flight," Science, vol. 232, 30 May 1986, pp.1075-6. Read the original.

Freeman J. Dyson, Infinite in all Directions, 1988, Harper and Row, ISBN 0-06-091569-2, Chapter 10, "Engineer's Dreams," pp. 180-200. Compares the Challenger accident and the Voyager success, with an analogy to the Scott and Amundsen polar expeditions.

See pp. 623-5 of Cost-Effective Space Mission Operations, by Daryl G. Boden and Wiley Larson, ed., 1996, McGraw-Hill, ISBN 0-07-006382-6. This is section 20.1, "Rationale for Human Missions," from Chapter 20, "Human Space Flight Operations," by Carolyn Blacknall and Felix Godwin. They cite another paper that I have in my file and was thinking of mentioning anyway, so I will:

"Logsdon, John. The Space Shuttle Program: A Policy Failure? Science, May 30 1986, pp. 1099-1105." This is the same issue of Science as the van Allen article.

Richard P. Feynman, "An Outsider's Inside View of the Challenger Inquiry," Physics Today, February 1988, pp. 26-37. Good general background on space program politics.

Lord Chorley, "Economics of Space and the role of government," Space Policy, August 1988, pp. 180-6. Since manned space flight is pretty much limited to expensive government programs for the time being, it's hard to talk about the role of humans in space without talking about the role of government in space.

James Bennett and Phillip Salin, "Privatizing Space Transportation," Reason Foundation Issue Paper, 6 March 1987, Reason Foundation, 2716 Ocean Park Boulevard, Suite 1062, Santa Monica, CA 90405, (213) 392-0443. This is arguably relevant because of the need, in my opinion, to examine the role of government and to get costs down in order for manned spaceflight to become readily affordable.


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