Towards a rational strategy
for the Human settlement of Space Paul J.Werbos This paper
revisits the core issues of space policy from the viewpoint of optimal decision
theory. First it argues for a metric: maximizing the probability that humans
and their technology in space someday reach what Rostow
called the "economic takeoff" point where autonomous growth becomes possible,
not bound by the rate of growth on Earth. Next it discusses three concrete
requirements to reach that point: benefits to Earth which exceed costs to Earth,
large and diverse enough "exports" from space to Earth, and advancements in
technology and infrastructure. Energy from space (ES) is now one of the most
promising export possibilities, based on what was learned in the last open Defining the metric to be maximized For most of us,
space is a means to an end. Thus no metric for performance in space can
perfectly represent exactly what we all would want, in the larger course of
history. However, we do
need a metric - a quantitative sense of where we want to go - in order to be
focused and efficient in setting policy and making decisions. This section will
propose a specific metric, based on the larger tradeoffs we humans face as a
species. This paper will address the challenge of space to
the human species as a whole, not the specific role of particular agencies like
NASA, NSF, DOD, UN, In the short
term, the future possibilities for human activities in space offer a myriad of
possible scenarios. But in the long term, these various possible trajectories
flow into three very distinct streams of possibility: 1. If human
technology and society do not reach a sufficient level of sustainability, the
economic and political base for activity in space may gradually erode, and the
entire enterprise - including even GPS satellites and communication satellites
- may terminate, gradually but permanently, as society reaches a certain kind
of static or stagnant equilibrium at a lower level of technology. Because our
economic rise over the past three millennia depended so heavily on low cost,
easily accessed natural resources, and on serendipitous disequilibrium in
society, it may be difficult to rise again as we have in the past. (Again, this
is a conceivable scenario, not a prediction. It does not specify whether humans
as such continue to exist on Earth or not). 2. Human society may reach
a kind of dynamic equilibrium at a level of technology and prosperity similar
to what we have today, in gross qualitative terms. In this family of scenarios,
GNP might be much higher, because of information technology and entertainment,
but space would still be used in a manner similar to what we see today. Space
would be a site for communication satellites, GPS, and some highly expensive
efforts at exploration and tourism which never reach an economic takeoff point,
and remain forever as a kind of side show. In economic terms, space would be a
kind of secondary sector without autonomous economic growth, exactly as in the
classical dependent "banana republic" [2]. 3. Humans and their technology
in space may someday reach what Rostow has called the
"economic takeoff" point [2], where autonomous growth becomes possible, not
bounded by the rate of growth on Earth. From the
viewpoint of Bayesian utilitarianism [3, 4, 5, 6], it
is rational for each one of us to think about the question: what are the
probabilities p1, p2, and p3 of these sets of eventual outcomes, based on every
thing that we know? But it is more rational to ask: what we can do to make p3 larger and p1 smaller? This paper will
focus on the question of what the human race as a whole could do to maximize p3. It will discuss the
possible roles of different actors - but success in this kind of activity
requires a great deal of flexibility in finding people to fill the many roles
and holes that need to be filled. This paper will not elaborate on the various reasons why we should
try to maximize p3. In the
end, that is a subjective matter, and I have described my own reasons for it
elsewhere [7, 8]. As a seeker of
rationality, I would not advocate that we focus exclusively on the goal of
maximizing p3. In this
paper, I will discuss how opportunities in space link synergetically
with equally fundamental long-term goals, such as the achievement of
sustainability here on Earth, in terms of energy and population and important
streams of basic science [9]; however, complete strategies for those sectors
are beyond the scope of this paper. Likewise, the
streams or "ergodic sinks" enumerated above lead to
further long-term branching. For example, even if we achieve stream (3), we are
not assured that the human race could continue to survive in space if humans
made the Earth itself uninhabitable. We are not assured that humans will be
able to reach beyond this solar system - if, in fact, that should be possible,
which is not at all certain for us. This paper will say very little about these
important issues, in part because we need to move into stream (3) in any case
before we can actually reach its best substreams.
These issues also require complex strategic thinking about technical details of
physics well beyond the scope of this paper [8, 9]. This paper
assumes that the situation we find ourselves in today, as a species, is a kind
of "crossroads situation". This is a specific kind of situation which can arise
in stochastic, nonlinear dynamical systems. The mathematics behind it were
summarized in [10], which described some mathematical tools which are widely
regarded now as new and promising tools within the field of engineering; Dual
Heuristic Programming (DHP) has recently shown that it can manage many electric
power systems far better than previous methods [11]. In [10], I did not
correctly translate the implications of that mathematics into policy terms
because I overstressed the role of the government as a center for
decision-making. Decades of experience within government have since improved my
understanding of the realities of political systems; however, they have also
reinforced the conclusion that we are indeed in a crossroads situation, because
of the way in which historical trends are playing out on Earth. The mathematics
of crossroads phenomena can be very complicated, but a simple example explains
the basic idea. Consider a dynamical system made up of n possible states. At any time t,
the system will be in one state i(t), where i is an integer between 1 and n. There is a "transition matrix," Pij,
which defines the probability that the system will be in state i at time t+1 if it was in state j at time t. Suppose that the possible states i fall into three sets - A, B
and C. For every state in set A, there is some probability greater
than zero that the next state will be in B
or in C. But for every state in B, the only possible transition is to
another state in B. For every state
in C, the only possible transition is
to another state in C. If you are in
a state in set A, your long-term
future happiness depends only on whether you finally get to B or to C. In reality, things may be more complicated. For
example, consider what happens if the probability of escaping B becomes smaller
and smaller with time, comparable to the probability of a table floating off a
floor due to atoms in the floor all pushing "up" together, by coincidence at
the right moment. For all practical purposes, this is still a crossroads
situation. In a crossroads
situation, short-term goals which seem very exciting and worthy are often like
"castles in the sand" - irrelevant achievements which get totally washed away
by the flow of events. The only thing which really matters in the long term,
for space policy, is the choice of which stream we get washed away to. Performance
metrics other than p3 are
a dangerous distraction, except when they represent tentative, changeable sub
goals well-calculated to serve the larger goal of maximizing p3. For example, the metric
of trying to minimize the time delay between now and the time when US
footprints next appear on the moon does not maximize p3; use of that metric has recently put NASA on a course
which would make p3
indistinguishable from zero, if there were not other actors in the game and hope
for mid-course corrections. Summary of Conclusions To reach the
economic takeoff point in space, we need a more tangible picture of what
scenario (3) entails. It does not require total self-sufficiency in space.
Based on economic theory, it requires three major ingredients: -
exports from space to Earth must be as large or larger than imports to
space from Earth. Space must deliver more value to Earth than it costs to Earth; -
exports and other production in
space must be large and diverse enough to rationally justify further investment
in space; -
technology and infrastructure in space must be advanced enough that the
"input-output coefficients" for production in space, combined with (2), lead to
multiplier effects large enough to generate takeoff. Humanity does not possess any assured or guaranteed path to meet all
these necessary conditions. Thus rational space policy is very similar to
wildcat drilling [4], in requiring a stochastic approach, a drive to "buy the
most valuable information" and an ability to shift gears very quickly as that
information comes in. Many of the more extreme errors in policy are based on
the tendency of humans untrained in stochastic thinking to try to form "an
opinion" (a deterministic prediction or rigid plan), to identify their entire
personality with that opinion, and to defend it past the point of absurdity. Requirement
1. This requirement is a long-term goal,
part of a set of goals which have not yet been achieved. There is no need to
demand that we achieve it immediately, before the other requirements are met.
If we consider the long-term fate of humanity, it is rational that we make a
net investment now, as part of a strategy for satisfying all three requirements
as soon as possible. The goal of increasing exports from space (requirement
two) will naturally tend to satisfying requirement one in any case. Requirement
2. It is possible but unlikely that
communications, GPS, media events and million-dollar tourists would be large
and rich enough to satisfy requirement two. To substantially increase the
probability of meeting this requirement, we need to drive to develop much
larger sources of possible revenue as soon as possible, with the highest
possible probability of meeting the real market requirements they entail. In my
view, the most promising single option today is the sale of energy beamed down
from space to Earth. Five years ago, I would have considered this conclusion
counterintuitive, but new results have come in from the NASA-NSF-EPRI funding
effort in energy from space (JIETSSP), which I co-chaired, and new trends in
world energy have underlined the great need for such a new energy source. Other major
possible sources of massive revenue include the tourism and scientific efforts
which might be possible if costs were much lower, Earth defense, space
manufacturing, the supply of scarce elements like platinum from space, and
efforts to massively improve Internet access and education for the rural (and
poor) half of humanity. The rational policy for now is to probe each of these
opportunities at a level of about $20-100 million per year, aggressively
exploring the highest potential technologies needed to make them fully
attainable. It will be crucial to keep these specific investments out of the
hands of those kinds of advocates or careerist opportunists who argue that "all
the problems have been solved," who cannot understand the problems, or who
overemphasize "low-risk" technologies which have little hope of ever reaching
the tough requirements of the free marketplace. We also need to create
institutions with the ability to scale up very quickly as soon as we are ready
to do so, in an economically rational way. This paper discusses energy from space in more detail below. Some sources of information on other possible exports from space to Earth are cited on the web page of the National Space Society, www.nss.org Requirement
3. There are a variety of important
technologies and metrics for technology, related to requirement three. Many areas
require improvement, from the biological side of supporting humans in space
through to in situ resource utilization (ISRU), deep space transportation, telerobotics and communications [1]. But for the present,
the most overwhelming threat to p3 is the lack of effective action to reduce
the long-term marginal cost per pound of lifting up material from Earth to low Earth
orbit (LEO) - "access to space." Many observers believe the NASA's current
plans for a permanent human presence on the moon will be doomed to failure, if
third parties do not offer NASA less expensive launch services soon enough to
allow low-cost resupply. In the long term, many serious researchers believe
that the lowest cost access to LEO will come from hypersonic vehicles
exploiting plasma effects ("Ajax"), space elevators, magnetic levitation like
Gerard O'Neill's "mass drivers" but on Earth, lasers pushing mass up from Earth,
and so on [12-14]. For several years, I managed about $1 million in NSF awards
aimed at studying the " Naturally, when
evaluating such claims as an NSF Program Director, I have checked with many,
many authoritative sources, some of which must remain confidential by law. The
most startling outcome of those checks is the conclusion that humanity is very
close to losing this option forever. It may even be too late already, but
rationality demands that we do our best to fill in this necessary hole
regardless of the difficulty. The problem is that the necessary technology for
tough hull structures, though declassified, was developed under "black"
programs overseen by the CIA. This technology was developed at an extremely
high cost at a time when the US spent a huge amount of money in this area (for
reasons related to the Cold War, made obsolete in part because of observations
satellites in space), and - more important - when the US had a great abundance
of the world's best engineers, highly motivated and led by patriotism to get
past the petty obstacles which tend to limit our bold technological
achievements today. We may hope that
the worst of those circumstances never arise again. In the meantime, essential
structural test articles have been lost or destroyed, engineers with the key
know-how have retired without training replacements, and essential papers and
reports are buried in garages of such engineers or in the trash can. One of the
key technologies, superplastic diffusion bonding for
honeycomb structures, has stayed alive in Rockwell and in what remains of
McDonnell-Douglas, but they need to be integrated with the actual structural
and materials technologies. It has been estimated that it would cost $30
million just to re-invent the most relevant and promising structural test
article which Boeing once developed, and $150 million to fully upgrade it to
incorporate new versions of the relevant materials. In terms of sheer logic, it
is grossly irrational for the human species to spend billions of dollars on
anything else in space before this urgent investment is made. Fortunately,
Chase's concept for a near-term vehicle [15, 16] would have dual use, both for
space transportation and for national security. Present mission models to LEO
in the There are two
main obstacles at present to building this kind of RLV with direct funds from
the Note that our
short-term "hot structures" crisis could also be solved by projects which do
not immediately get us to the $200/pound-LEO which we need in the long-term.
For example, development of an upgraded, safer and less expensive version of
"Shuttle C" could use these kinds of structures. In its recent design study
under Michael Griffith, NASA rejected the Shuttle C option because of
turn-around costs and the danger of foam hitting delicate seams between tiles,
as it did in the recent shuttle explosion; use of hot structure materials
instead of those tiles would solve both problems. Likewise, research programs
in hypersonic (aimed at speeds beyond Mach 10) should rationally pay for this
work, if no one else does, as soon as possible - because they will need it, in
order to have any hope of delivering real vehicles. Energy from Space: Highlights New options have
arisen for generating energy in space and beaming it to Earth which totally
change the policy tradeoffs. The situation is very different from what I would
have thought in the year 2000. The global energy situation itself has also been
in flux. Near the start
of this decade, the UN-affiliated project in futures research called the
Millennium Project (www.stateofthefuture.org)
did a survey of science policy makers and decision makers all over the Earth.
They were asked: "Of all the many things that science and technology might do
to improve the human condition, which would be most important and valuable?"
The number one answer was: "Develop a new non-fossil non-fission source of base
load (24/7) electricity, large enough to meet all the world's needs." This
report was decisive in persuading James Mink and myself
of NSF to approach NASA, and join forces in a small new funding initiative in
2002 called "Joint Investigation of Enabling Technologies for Space Solar
Power" (JIETSSP). At this writing, the JIETSSP solicitation (including
citations to prior work) can still be found by use of the search engine at www.nsf.gov. The workshop report which helped
pave the way for JIETSSP has been reposted at www.werbos.com/space.htm. John Mankins of NASA and I served as co-chairs of this effort,
the last explicit funding of energy from space in the The reason why
the international policy makers answered as they did is that they were aware of
very frightening trends involving carbon dioxide emissions and also involving
future nuclear proliferation (related to a growing need for enrichment and
advanced reactors, and diffusion of the technology on a larger and larger scale
to areas where access is not perfectly controlled). The details of climate
change may be debatable, but at this writing there is near certainty that human
emissions of CO2 lead to a massive increase of acidification of the
oceans - a phenomenon which killed more than 90% of the life in the oceans in
the handful of times when it occurred before, in geological time. Reflective
particles in the atmosphere and other easy "quick fixes" would not solve this
aspect. Personally, I believe that it is grossly naïve to pretend that we
are certain humans will continue to exist on Earth if these trends continue. and they are already facing
difficulties in producing and importing as much coal as they need. (Source: To achieve a global sustainable energy system
[10], we need to meet all three of certain very challenging requirements: (1)
to find enough sustainable affordable car fuel - most likely by an accelerated
use of plug-in hybrid cars, which draw at least half of their energy needs from
electricity, or by future cars which store energy in other forms (like heat or
hydrogen) produced locally from electricity from the power grid; (2) to replace
natural gas being used to generate daytime electricity, most likely by using
new low-cost solar thermal energy farms linked to electric utilities; (3) to
replace both coal and fission for the bulk of base load (24/7) electricity
generation, which is likely to grow as we use electricity in more and more
applications. Energy from
space - unproven as it still is - is our best hope by far of meeting the third
requirement, at a cost similar to what coal and fission cost today, on a scale
large enough to displace them. Some say that methane gas hydrates are another
major hope - but for now, they seem to involve greenhouse gas problems even
worse than coal, and a supply of fuel as large as coal but far form unlimited.
Wind is growing in efficiency, but few authoritative sources claim that it
could meet more than about 20% of our present electricity needs. There is some
hope of using low-cost solar farms on Earth, and then using long-distance
transmission, intelligent grid control and overnight storage to meet nighttime
needs; however, it now seems unlikely that this could get as low as 10 cents
per kwh, twice what coal and nuclear cost. A very
large carbon+fission tax could level the playing
field here, but it would be more sensible to wait until solar farms have fully
penetrated the daytime electricity market, and hope that we can do better with
energy from space. A small carbon+fission tax
recycled to the sustainable energy sector might be a good mechanism to speed up
technological progress, and close the small gap (if any) between the future
cost of energy from space and the cost of electricity from coal or fission. But can we
really better with energy from space, compared with storing Earth-based solar
power? In the late
1970's, NASA published two "reference system designs" for space solar power
which were claimed to offer 5.5 cents per kwh
(in 1970's dollars). At the time, I was lead analyst for long-term energy
futures at the Energy Information Administration (EIA) of DOE; in that
capacity, I assisted the team of Fred Koomanoff at
DOE Much later, John
Mankins at NASA worked very hard to fill in the
vacuum here. Through his "fresh look" and "SERT" studies, he first verified
that the old reference designs would not work. Then he funded the development
of new designs which were far more reliable and validated. He also funded far
more credible life-cycle cost analyses, such as the work of Molly Macauley of Resources For the
Future and work at SAIC. In our joint
technical interchange meeting of October 2002, the SAIC people reported that:
1) certain new designs developed up to that point had a very high degree of
reliability on the whole, and could be costed out to
a reasonable degree; 2) the best of them would still cost 17 cents per kwh; 3) 4 cents of that is the cost of microwave power
beaming, including antenna, rectenna and power
hookups; 4) most of the cost is proportional to the cost of transportation -
with these estimates requiring $200/pound-LEO and $200 more to GEO. Fortunately,
three new design options emerged from that meeting and from discussions
following up on that meeting: -
Richard Fork and I proposed a
new "backbone" or "spinal cord laser" design, which would convert solar light
directly to coherent light (no electricity steps!), and beam it down to Earth
as continuous radiation, at a cost probably in the 10-20 cents ballpark,
without the need for a rectenna. -
Mankins and Marzwell proposed a new "sandwich
cell" design, using high-efficiency "sandwiches" of concentrator solar cells
and a thermo-electric layer, drastically improving the previous designs based
on solar cells. -
I proposed [10] a new design,
using pulsed light-driver lasers to ignite fusion in a new type of fuel pellet
developed by John Perkins of Lawrence Livermore, producing electricity to be
beamed to Earth by microwave. The Mankins/Marzwell design is close
enough to previous designs that we can have reasonable confidence that John's
estimate of 10 cents per kwh can be achieved, if we
don't lose our option to get to LEO at
$200/pound. James Mink - former editor of the IEEE Microwave Theory and
Techniques (MTT) journal - convinced us that power beaming by microwave will be
at least as safe as cell phones (and far safer than fission or coal!), even
though it needs some demonstration work, and some assurance that the
international community will allow some reasonable narrow frequency bands for
this use. (The frequency issue would be easy to solve at present, but some
regard it as a serious crisis.) The microwave community also has stated that we
have a good chance to cut the power beaming cost in half or more, if we support
aggressive advanced research, drawing on new technologies such as superresolution, smart antennas, lightweight materials,
integral design and higher frequencies. A key part of the Mankins/Marzwell
design is the use of lightweight mirrors or lenses, such as those developed and
validated by Entech, which offer far more
concentration than the mirrors available for solar power systems on Earth. (On Earth,
gravity requires bulky, heavy structural elements and designs which fight
gravity, unlike inflatable sorts of mirror systems which work fine in space.)
Another key part is the use of new "heat pipe" technology developed only
recently. Some very respected critics
have argued at times that Earth solar power "must" always be cheaper than space
solar power, because the ultrasafe receiving antenna on
Earth used in the Mankins/Marzwell design captures
energy less than half of the solar light hitting the Earth. This is a classic
example of bad arithmetic, driven by strong emotions blinding human
rationality. The energy received per acre of desert land is not a major cost
driver, because the cost of desert land is a small factor both for energy from
space and for rational solar farms on Earth. My design
concept is riskier, but it offers a greater hope of truly deep cost reduction.
The primary source of risk is the design (and assembly) of the laser. Leading
laser designers have assured me that they know how to design this kind of
laser, using new materials such as photonic bandgap
materials. Lawrence Livermore Laboratories (LLL) have not yet finished the Earth-based
laser they need to actually test their pellet design, but they do operate the
world's largest (Blue Gene) supercomputer at present, and their careful
simulations do have a rich empirical basis behind them. I propose the use of
their new D-D pellet design, primarily made of deuterium, an element present in
vast quantities in the seawater of Earth. When D-D pellets are used in space,
the energy emerging from the fusion reaction is 80-90% composed of electrical
currents. (Fusion on Earth may always be more expensive than fusion, because it
requires large expensive heat reaction systems, extracting energy which comes
out as heat; however, vast amounts of vacuum are available for free in space,
and allow us to use simple transformers instead of heat reaction systems).
Crudely speaking, my design would require a laser twice as big and expensive as
the Fork/Werbos design, but the D-D "afterburner"
would yield a hundred times as much electricity. That
multiplies the cost by per kwh
by about (2/100) - implying that we have an excellent cost of reducing the cost
of generation to under 1 cent per kwh. (At $200 per
pound-LEO, we have to add 0.1 cents for the cost of lifting up the pellets from
Earth.) At these low generation costs, it is conceivable that laser
transmission of this energy to Earth might make economic sense, even if it is
less efficient than microwaves - but we don't really know as yet. In JIETSSP, we
only had $3 million to spend, which we distributed over 12 projects, mainly
based in universities and small businesses like Entech,
based on an open competition for new ideas and experiments. But the review
panels recommended that we fund $21 million worth of the excellent creative new
ideas which we received. This is one reason why I believe this would be a
reasonable minimum level of funding here. A rational approach would begin by swiftly
developing powerful new simulation models (as suggested by Jon Dowling) capable
of effectively evaluating new concepts for a space-based high powered laser,
and then would support a wide-open competition funding many teams to try to win
the competition for best competition in simulation (with modest laboratory-based
experiments to back them up). Then, when we have a better understanding of the
possible costs and feasibility, we can proceed to scale up to higher levels of
technology readiness. The particular Technology Readiness Level (TRL) strategy
developed by Mankins at NASA comes closer to a
rational decision-theoretic approach than anything else I have ever seen in
government procurement. Conclusions No matter what
policy we adopt, we cannot guarantee that humans will ever be able to settle
space in a sustainable, cost-effective way which makes a net contribution to Earth. However, the
possibility may be there; a rational global space policy would maximize the
probability that we achieve that hope, sooner or later. Our probability of
success will be greater if we try to reach sustainability as soon as possible,
by focusing heavily on developing larger "exports" from space to Earth, and
developing the technologies and infrastructure which can reduce costs. No matter what
kind of exports we seek, we will need cheaper access to space to make it
possible. We have a very good chance of getting to $200/pound-LEO in 5 to 10
years, if we act soon. But we also face a very real risk of losing that option
forever if we do not give it greater priority, and learn to overcome the
conflicts and rivalries which have prevented progress in the past. Earth-launched
energy from space (ES) is the leading hope for now for providing the necessary
level of benefits from space to Earth. I would like to see a major
international commitment (starting from a few core partners) to try to have gigawatts of electricity beamed down to Earth, in ten
years, at a marginal cost of 10 cents per kwh or
less. This would be approximately as risky as trying to go to the moon in ten
years, starting form John F.Kennedy's speech. It
calls out for a commitment, like Kennedy's, to take the efficient road - holding
down costs by developing new technology and infrastructure, even though it may
add a risk of a 5-year delay. Risky as it would be, it would reduce the risks
that really matter to the humans species - risks
related to nuclear proliferation as enrichment technology starts to spread, and
risks related to pollution and the less-than-infinite world supply of coal. In the past,
great visionaries like Gerard O'Neill and David Criswell claimed that ES would
be much cheaper (and human settlement of space more assured) if we could
somehow use materials from the moon to build the kind of systems I have
discussed here. I still agree
with that claim. NASA's goal of developing the moon [1] is a very important
part of the human space program. However, the success of that longer-term
effort will depend on developing a more direct market for lunar products and
materials, and on developing crucial infrastructures and technology. Human
development of ES and other activities in Earth orbit, in the mid-term future,
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