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Reminiscences on the End of the Hope for
Primates in Space
Paul
J.Werbos*)
This
paper addresses the question of whether humans will ever be able to settle
space in an economically sustainable way and, if there is still hope of this,
where the greatest hope may lie. It reviews key developments of the last 40
years relevant to this issue, such as the space shuttle, the National Aerospace
Plane, the Russian Ajax effort, nonlinear control challenges, challenges of
developing a "skin" to withstand re-entry, current space programs around the
world, and key markets for using such vehicles, such as energy from space and
space manufacturing.
1. The Beginning of the Hope
Very powerful mathematical tools have
been developed, and are still being developed, which could play a crucial role
in allowing humans to achieve economically sustainable settlement of outer
space [1-5]. Unfortunately, the global dynamics of science and technology as a
cultural system are coupled with larger economic and political dynamics all
over the earth, in such a way that the probability of humans moving out in a
permanent, serious way into space now seems only slightly larger than the
probability of monkeys learning to fly on their own. There is still some hope,
logically. It is not rational to give up hope when it is a matter of survival
of an important endangered species (humans), but all the remaining hope
requires some understanding of the larger situation. The author would like to
express his thanks to Dr.L.K.Kuzmina for asking him
to give some reminiscences on the progress and challenges in Space exploration,
which he has been part of here.
Of course, the hope for humans to settle
space in a sustainable, permanent way goes back to people long before the
author was born. People who read this journal probably all know about
Tsiolkovsky more than the author does. Even in the
Still, in considering this vision of
Ehricke, a cartoon story has sometimes appeared in the author's mind. He sees a
beat-up talking fish in the ocean (a bit like himself in some ways) who is
talking to the other fish. The fish says: "I have succeeded in the great
ambition to visit that other world above us, to explore and to learn what our
true role in the universe really is. In that greater world, they call us
sashimi:" Not exactly, but in order to be "rational" as defined by von Neumann
and Morgenstern [7, 8], it is important that we consider a wide range of
alternative possible scenarios.
This paper will discuss a lot of earlier
history, precisely because of the pressing needs we have today. Most of the
space policy makers today are on track to repeat the same kinds of mistakes they
have made in the past, both at the political level and at the technical level.
Only by learning the lessons of past mistakes could we have much hope at all
for success in the future. The author will discuss this from his personal viewpoint, because that is the original database he has to
work with here.
*) The views
herein are just the author's personal views. They do not represent the views of
any of the organizations he has worked with or for.
2. The Early
Shuttle Era
The author's own journeys into the human
space program began in graduate school, in the early š1970's. šActually, he saw the first moon landing on TV in š1969, šon a television in
Back at Harvard that year, the author
learned of the then recent seminal NASA reports by George Mueller of the
Goddard Space Flight Center (GSFC) in
Mueller showed that the actual fuel cost
of getting to earth orbit is much, much lower than the cost we were paying for
the Apollo program. He performed an in-depth analysis of many sources of cost
in traditional 1960's launch technology. Above all, he developed a
comprehensive strategy for how to minimize that cost. He performed tradeoff
studies for airplane-like reusable launch vehicles, two stage to orbit (TSTO)
and single stage to orbit (SSTO). He also provided a concept of operations at
airports, to minimize the cost. These NASA reports were widely available, and the
author read them in the Harvard library.
Mueller's reports were exciting and
electrifying to the author, because of his own previous efforts to understand
the dynamics of historical processes and the role of key technologies. The
author recognized immediately why this breakthrough would be crucial in opening
up a viable new economic frontier in space [4], and in creating a new means of
production with profound implications for the social and political level of
human life. He wrote and distributed a one-page advertisement on this, and
created a new recognized student organization at Harvard, the Harvard Committee
for a Space Economy (HCSE).
HCSE was a remarkably entertaining group
of people. All of the dozen or so active members had degrees (earned or being
earned) BOTH in natural science or technology, and in social sciences. One of
the members was famous for having built a workable intercontinental class
missile in his backyard when at high school, and was then working for GE while
at Harvard. Our discussions for future options in space were highly creative,
well anchored in the political and economic context. Three pillars of future
economic settlement of space were mainly discussed: (1) Mueller's space shuttle
proposal; (2) space manufacturing, with some discussion of a few other possible
markets; and (3) materials to be extracted from asteroids, where it is not
necessary to waste so much money and energy to fight a gravity well.
In 1972, the author's closest friend in
Harvard at the time invited him to ride with him in his car to the Republican
national convention, where it was planned to nominate Richard Nixon, who
promised to get past the now obsolete Apollo era of "flags and footprints" but
also promised to create a new renaissance in space (similar to what Brezhnev
had promised). But something very strange happened along the way.
The friend asked the author to stop along
the way at
A Christian Fundamentalist friend in the
Harvard mathematics department had been urging the author for years to read the
Book of Revelations. Based on how he talked about the book, the author never
had much interest. But he did like to read science fiction, and this was the
closest he could find in that apartment. So he spent a few hours reading it
very closely and once again he was very surprised. In some cases, he remembered
the Latin words close to some of the English text, and could see some immediate
associations his friend was clearly unaware of. The author was amazed to see
the close relation between parts of this book and a paper he had written the
week before. There was a city floating the heavens, like what the author with
his companions wanted to build. There was a kind of "ark" in the heavens, which
reminded the author of Mueller's idea for a space shuttle. There were a number
of parallels he would not want to discuss here. And there was discussion of
about twelve "crystals," which sounded a lot like some of the proposals the
author had seen when he visited the GE Valley Forge space manufacturing center.
He checked the dictionary, and found a one-to-one match, with just one
exception.
The author with his friend never made it
to the Republican convention. After the interaction with his girlfriend, the
author's friend just drove them back to Harvard. At Harvard, the author asked
the GE guy about the one exception: "Is there any use for THIS crystal?" He
suddenly looked worried, looked around for people listening, and asked: "How
did you find out about that one? It is not supposed to be possible. If you can
tell us where you read about this, maybe we can do something to limit its
distribution." The author tried hard to contain his laughter, and calmly said,
"No, I do not think that that would be so realistic in this case."
Nixon was elected in 1972. Nixon did keep
his promise to replace Apollo with a space shuttle, originated by Mueller.
But Nixon had "friends." He had friends
in
After Nixon's election, half of the press
reported that a momentous decision about the future of NASA was made by the
Office of Management and Budgets (OMB). In comparing Mueller's design with
Nixon's tweak, they agreed that Mueller's design would lead to much less cost
per flight, but they argued that it would entail more money and risk to
develop. Comparing operations cost with development cost, and assuming a very
limited "mission model" for the future of NASA, they argued that more money would
be saved by funding the Nixon tweak instead of Mueller's original proposal.
Half the press was much more cynical, and
suggested that the OMB study was basically just a whitewash for a decision made
by Nixon himself, based more on sources of campaign funds than on long-term
needs. Nevertheless, the OMB study set a precedent and established a
methodology. In actuality, the only justification for building a new launch
vehicle was to lower costs, in order to increase the probability that humans
really could expand their economic activities in space, which is simply not
plausible when it costs $2,000-$20,000 per kg LEO. But myopic approaches to
decision making essentially do not consider such hopes, and are effective means
of preventing them from ever becoming real.
The myopic approach to decision making
creates a severe "chicken and egg" problem. In the
The press reported
that OMB also considered another factor, which did not sound so clear to the
author at the time. They reported that OMB was also worried about risk.
Mueller's approach, they said, depended very heavily on new technology for hot
structures, which was new and therefore risky, which had been developed in
classified research. History has shown that the "safe" path of relying instead
on tiles and foam and o-rings in solid rocket motors was a great source of risk
itself. The author has seen many cases in other domains where people used older
technology because they thought that "old" means "safe," when in fact it is the
opposite, simply because the older technologies have less ability to withstand
the challenges of the application.
The Richard Nixon tweak became the space
shuttle. Nixon also cut back on the overall NASA budget. In 1972, the author
also decided to divert more of his personal energy to solving some important
problems in applied mathematics, for his PhD thesis (reprinted in [10]). He
turned over control of HCSE to Mark Hopkins, who was vice-president of it
before then. HCSE did not last long in its initial form after that, but Mark
Hopkins then worked with others like Keith Henson to establish the L-5 Society,
which played an important role in the next chapter.
3. The L-5 Era
and Space Solar Power (SSP)
The movement for human settlement of space
was energized to a huge degree by seminal books and papers (such as [11, 12])
by Professor Gerard K. O'Neill of
In 1975, the author joined
with his student Gary Barnhart and a friend of his to start a new space
organization, the Maryland Alliance for Space Colonization (MASC), based in the
Support for this general vision grew
stronger and stronger in many sectors, especially as boycotts of oil in the
Soon after this effort began, the author
was contacted by a key manager at DOE, who had previously hired one of his students
(Jim Titus) who told him about the author's mathematical methods for political
and economic forecasting. After seeing how effectively the author had
accidentally uncovered major gaps in global conflict models used by the
Department of Defense [13], he offered the author a job in the tiny group at
DOE responsible for evaluating all energy models across DOE and its
competitors, and responsible for informing the Secretary of Energy about what
we really know about the energy future. The author gave up academia because he
felt that this was too important a call to ignore. As a result, he ended up
providing technical support and liaison to Fred Koomanoff of the DOE Office of
Energy Sciences, which was responsible for the DOE part of the SSP effort. At
about the same time, he was elected a Regional Director of L-5, which Mark
Hopkins was effectively running throughout; he appointed the author to be the
L-5 representative to the
The NASA part of the SSP effort funded
three design efforts for SSP. By NASA's rules, two of these efforts
(Lockheed-centered and Boeing-centered, as best the author recalls) were
restricted to SSP designs to be launched totally from earth. These were later
called the "NASA Reference Study Designs," and are widely available from NASA
still. The total price tag they proposed was huge, on the order of $1 trillion
over many years to produce a huge amount of power. However, they estimated that
the ultimate cost of the electricity would be only 5.5 cents per kilowatt-hour
(kWh), in 1970's prices. There was also a third major study, deliberately
publicized less, which evaluated the original vision of O'Neill, and concluded
that it would indeed allow a huge saving in cost compared to the Reference designs.
The L-5 community was quite upset that
this third study did not receive more attention. Why lose the option to save
money, and finally overcome the barriers to human settlement of space, both at
the same time? Why suppress this option?š
As the author thinks back on this, he cannot help noticing that the two
reference system designs would have meant more money foršš Lockheed or Boeing: IF
they had been funded. Incentives to minimize costs are not always as
strong as they should be in government contracting. But as the author looks
back, he also remembers how he has learned to be somewhat skeptical of
O'Neill's initial cost estimates.
The DOE study, led by Koomanoff, was much
less optimistic than the NASA study. It pointed to many technical questions and
unproven assumptions in the Reference System designs. We did not argue that
funding for SSP should be terminated; rather, we argued that key uncertainties
needed to be addressed head-on, and new R&D conducted, before people rush
ahead to deployment. Unfortunately, irrational emotions opposed to SSP and
space in general were even stronger and even crazier than the emotions of those
who simply believed the Reference system study or O'Neill's book. Groups such
as Ralph Nader's basically quoted us out of context, and introduced red
herrings of their own, and the program was killed.
It was very disturbing to see allegedly
mainstream evaluations in major scientific journals, which would compare SSP
with earth-based solar power based on cost estimates which assumed 1990
predicted costs for photovoltaic on earth, and 1960 costs for photovoltaic to
be used in space. It was also somewhat shocking to see some energy "experts"
proposing that we should make a choice between these two options based on the
amount of desert land they would require per kilowatt of peak power; this is a
grossly irrational approach to analysis for many reasons, such as the fact that
the cost of desert land is a very minor cost factor for both technologies.
The greatest logical error by opponents
and advocates of SSP was the assumption that the world must choose just one
best source of electricity, for the time when fossil fuels run out or become
too expensive. The best plausible hope for the future at present is that
earth-based solar farms and energy from space (including SSP) may both someday
provide steady, reliable electricity at a cost of 10 cents per kWh, enough to
meet both the base load 24-hour demand and peak daytime demand without major
additional costs to the electric power grid.š
SSP is a complex and risky technology which may take some time to
perfect, even if we begin aggressively now. However, without SSP, we will need
to make huge changes in the operation of electric power grids, which are also
complex and difficult [14]. Because our lives now depend on maintaining a safe
and reliable source of electricity, the safest policy is to work hard on both
possibilities. It is also interesting to consider how the new computer tools
and approaches used to upgrade electric power markets might be used to achieve
more stability and optimality in some other markets.
At about 1981, as the author's work load
at DOE grew, he turned over the job of L-5 representative to a colleague of his
at DOE, Gary Oleson. Gary Oleson worked closely with Jim Muncy, who worked with
Republican Congressman Rohrabacher, who remains a key force in space policy and
a strong advocate of US-Russian collaboration. Oleson and Hopkins were key
people in organizing a merger of L-5 with Von Braun's National Space Institute,
to form the National Space Society (NSS), a major force even today. Likewise,
as NASA remained unresponsive to O'Neill's vision, some of our friends turned
to DOD, and put a spin on the High Frontier concept to try to get money from
people interested in missile defense (but more interested in expanding federal
funding). The people interested in missile defense were quite sincere about
being open to partnership with the
4. The creation
of NASP
While the author was still L-5
representative to the federal government, and studied the details of the
various SSP proposals, he realized more and more how important it was to return
to George Mueller's original agenda, to try to minimize $/kg-LEO. He discussed
this with Dana Andrews of Boeing [15], who was part of the L-5 movement but
also a leading expert on space transportation, aware of Boeing's work on the
Trans Atmospheric Vehicle program. (By the way, the author's old security
clearance lapsed before he started work at the Department of Energy; thus he has
never had access to any classified material through his entire career in the
federal government, except for one brief conversation about neural networks
unrelated to anything in this paper.) The author was also excited about the
possibility of using air breathing vehicles instead of rockets to lower costs
even more than Mueller's original proposal.
A friend of his from MASC days, Bruce
Friedman of B'Nai Brith and the Naval Academy, played a crucial role in
arranging discussions with a few key offices in Washington, to follow up on
this interest.
First a discussion was held with a local
Republican office in Congress, to create at least one local supporter, to call
for serious attention to the issue. Then a decisive meeting with Jonis was arranged, the number two guy at Reagan's
Strategic Defense Initiative. It was noted that if we really could reduce
$/kg-LEO by a factor of ten, then for the same dollars we could afford to orbit
ten times the payload. After checking the math, Jonis took over (with only a
bit part for us), and things went very well.
It was a moment of really enormous
excitement when President Reagan announced his new "Orient Express" or
"National Aerospace Program (NASP)" priority, in his State of the Union speech.
It seemed as if the political problem was finally solved, and we could finally
move on to working out the technical details and making it real.
NASP was set up as an interagency effort,
run by a Joint Projects Office (JPO) based at the Wright Patterson Air Force
Base (WPAFB) in
5. NASP: From
start to finish
From 1988 to 1989, the author moved from
DOE to the Engineering Directorate (ENG) of the National Science Foundation
(NSF), to take over new programs in neural networks and in Emerging Technology
Initiation (ETI). One of his first actions was to set up a workshop in New
Hampshire on the use of artificial neural networks to solve difficult problems
in control, which led to a book [16] intended to focus my funding and create a
new field of "neurocontrol" combining neural networks and control theory.
At that time, the
author also attended the IEEE Intelligent Control Conference in
But the author did
have such methods. He asked Pap whether he would be willing and able to prove
this, by making the connection between new neural network control methods and
NASP. He said yes. The author soon signed off on the small grant which was the
first funding of AAC, and which started that company on a course to tremendous
growth for many years after that. (At one point, AAC made it to the INC 500
list of fastest growing companies in
Pap and the author both understood that
the insertion of new methods demanded that they build a partnership with the
NASP JPO, which led that effort. Thus both of them had some important visits to
WPAFB. (The author still remembers his great excitement one time when he saw a
big plaque "WPAFB INNS" where he stayed one time. He thought "they are very
serious about collaboration with the International Neural Network Society." But
no, it was just one of many inns).
On the first visit,
with Pap, the author asked them what kind of benchmark control challenge they
could offer, which Pap could use to prove himself worthy of their funding,
which he would work on under NSF funding. They mentioned a difficult nonlinear
trajectory optimization problem, for which they had spent millions of dollars
and several years at a major aerospace company, to find a solution which was
still not quite perfect. The equations were normal air breathing vehicle
equations, but the parameters, the speed, and the required maneuvers were all
beyond what humans could handle and beyond more conventional controllers.
Pap found a very quick and easy way to do
well in that application. He translated the control problem and tricky
maneuvers into a video game, played at a speed slowed down enough that a human
could cope with it. Because humans enjoyed this game, many of them worked hard
to get to the highest level, and meet the tough NASP requirements at slow
speed. Only two of them succeeded, but the computer recorded how those humans
behaved. He trained a simple recurrent neural network to copy the human
behavior, and then showed that he could easily run that neural network at the
speed of the actual system. For a small fraction of the cost and time, he met
the specifications. In essence, he used the strategy now called "behavioral
cloning" which the author first proposed in [16]. After that, Pap's company
built a stronger partnership with the
For the very next
stage of the AAC work, the author was hoping to get a mathematical
representation of the original challenge suggested to them by George Lea. This
required coupling the body, the engine and the environment of the vehicle. The
author was somewhat disappointed when he learned that these aspects were being
handled by separate activities, which were planned to be integrated some time
in future years. He was also quite worried about what this division of effort
would do to the ultimate success of the program, if the pieces were not
designed to allow a solution of the combined control challenge. Therefore he pushed
Pap and JPO to try to do more integrated modeling, to set the stage for
addressing Lea's challenge.
In parallel with this, he met two
energetic and creative engineers from McDonnell-Douglas of
One
year, when the author heard from White that continued funding for NASP was in
doubt, he volunteered to join the NSS group visiting the office of Senator
Mikulski for their annual space policy discussion. Kevin Kelley represented
Senator Mikulski. Kelly said he had grave doubts about NASP, because of the way
the procurement people had somehow cut out Boeing, the company whose
contributions would be most essential to the success of the program. There was
also some concern that NASP was falling into a common set of overspecialized
activities, which some called "paper airplanes," without enough systems-level
reality testing. The author remembered what Dana Andrews had said about TAV,
and wondered. In retrospect, he wishes he had done more than just wonder. He
wishes they had worked harder with Kelley to solve the problem back when it
would have been easier.
Back
in
White was able to imagine one possible way out.
With a complex system of smaller scale valves (such as nanotechnology valves
discussed by Ken Gabriel at the time), and a very advanced form of neural
network control, it seemed possible to reduce the TPS weight dramatically.
Tests were just starting of this option at about the time when NASP was
cancelled. Perhaps it would have succeeded, but it involved new technologies
far more aggressive and risky than others that were discussed, and it would
have introduced many unnecessary risks.
Just
this past year, a colleague in NSS pointed the author to the official NASA
history of the NASP era [17]. It was a great shock to learn that the people who
implemented NASP began, as a first stage, to cancel the TAV program. If the
author had expected that, with what he knows now, he would probably have
skipped NASP altogether. Valuable as it was, NASP was not worth the
cancellation of TAV.
6. Traditional
Hypersonic After NASP
The cancellation of NASP, after the
cancellation of TAV, marked a low point in US activities in hypersonic.
In
the last stages of NASP, when there was pressure to demonstrate some kind of
holistic vehicle, people looked around to see who had been working on NASP, who
had been trying to integrate the pieces. Ironically, AAC suddenly occupied a
central role for a short time, because that was the
direction the author had been pushing them into.
At
one point, Pap put together a kind of bottom-up hypersonic program, by
combining small grants, mainly from Small Business Innovation Research (SBIR)
from multiple agencies, to add up to an entire vehicle. His LoFlyte vehicle was
briefly the flagship of active, operational hypersonic in the
LoFlyte
was a scaled down (1/3 size?) flying version of a "wave rider" airframe, based
on work and guidance from Isaiah Blankson of NASA headquarters and his grantee,
Prof. Mark Lewis of the University of Maryland. Pap could only manage a small
engine for this airframe, but he argued that the main control challenge here is
to overcome the instabilities which a Mach 5.5 airframe would have at low
speeds. He demonstrated that he could overcome those instabilities by using
neural network control, both in simulation and in a whole suite of test flights
out of Edwards Air Force Base and elsewhere. Reporting on his NSF grant, he sent
success story videos to NSF which was presented at the highest level of the
agency.
Some
of the further developments at this stage would be somewhat embarrassing to key
people. As a result, the author has posted the most important (and amusing)
details on the web [18], with important names shifted or deleted.
Hypersonic
research has certainly continued after that time, especially in relation to
research on scramjet engines all over the world. There are some efforts whose
primary objective is simply to keep the money flowing, without so much serious
attention to the coupling between funding and ultimate outcomes. Scramjet
engines and wave rider design may be necessary parts of air-breathing RLVs, but
they are not sufficient for overall success. Overall success is now very much
in doubt, for many reasons, some of which will be discussed.
7. The
Circa 2000, there
was growing interest in the
Three
government agencies sent people both to AIAA conferences and then to
quite as hard as they might have.
After extensive peer review, and rejection of some proposals by people widely
respected in the DOD funding community, the program the author run funded two
important and successful efforts: (1) a small effort to Stevens University,
with a subcontract to AAC; and (2) a large effort to ANSER corporation, under
Ramon Chase, with a major subcontract to Richard Miles of Princeton and a
number of smaller subcontracts, including one to Mark Lewis. The latter program
hosted quarterly technical review workshops, with presentations from other centers.
The author has previously published a
paper in this journal [2] summarizing the main technical lessons learned, and
new opportunities, towards the late stages of these projects. Chase himself had
acquired incredibly important unique knowledge of hypersonic through the years,
in part from his role in successful on-budget earlier efforts to develop the
highest speed air breathing vehicles in human history.
The
work by Stevens and by ANSER was both important and successful, but the two
groups had very competing visions and personalities, which made cooperation
difficult. Ganguly of WPAFB achieved the greatest success that the author knows
of in core
The
ANSER work ended in a less graphic way. The award received a small follow-on
from WPAFB, which took over management. Some of the technical issues which they
had been probing in their term no longer received the same attention. In
October 2003, funding rates in the division the author worked at in NSF dropped
very abruptly to only 10%, forcing abandonment of a number of key technologies,
from plasma hypersonic to quantum learning. But technical factors also entered
the story, as will be now explained.
8. From Joint Investigation of Enabling Technologies for SSP
(JIETSSP) to the Challenges of the Present
While all this work on hypersonic was
going on, there was also renewed interest in space solar power (SSP). In the
1990s, perhaps in part due to the efforts of Congressman Rohrabacher, NASA was
funded for a "fresh look" study of SSP, led by John Mankins of NASA
Headquarters. Mankins' program, SERT, checked some of the issues raised in the earlier DOE evaluation, and verified that the
earlier Reference Designs would have failed if they had been naively funded
(just as NASP had failed).
However, SERT also developed an entire
suite of more viable designs, which passed extensive testing.
In
the late 1990's, the author contacted Mankind on behalf of NSF, and proposed
that they hold a joint workshop on the use of advanced learning technologies
like neural networks as a possible enabler for low-cost SSP. The NSF-NASA
workshop on that topic was held in April
The key need for machine learning in
earth-launched SSP is to allow greater use of robots in assembling large space
structures, to hold down cost. It is too early to make certain key technical
decisions on the details. In general, we now envision human operators in warm
space stations, each controlling about ten semiautonomous robots, through teleautonomy, to perform assembly and maintenance, building
on what has been learned from real-world mining and construction robotics.
By 2002, more information had become
available [19] supporting hope for SSP. Jerome Glenn, then the director of the
UN University Millennium Project (www.stateofthefuture.org,
not to be confused with the later UN Millennium Project), had been commissioned
to do a study of science and technology policy world wide. When asked to name
the most important new contribution that science and technology might make in
the coming century, the most votes went to the topic: "affordable large-scale
nonfossil, nonfission source of base load electricity." SSP was by far the most
serious candidate for that particular requirement. Also, the National Academy
of Sciences conducted an extensive review of the new SSP concepts from SERT,
and published a report (publicly available on the web) supporting the area.
Building on that support in 2002, the
Engineering Directorate of NSF authorized the author and a colleague (Dr. James
Mink, a leading expert in microwave technology) to visit NASA and propose a new
joint funding program, to carry on past the recently cancelled SERT program.
NSF did not endorse SSP as such, but agreed that basic research aimed at
developed the required enabling technologies would be of great value in any
case. The author then led this activity [19], in a 50-50 partnership with NASA,
with him taking on the actual operational leadership.
The great funding collapse of 2003
prevented a continuation of this activity, but many important things were
learned from it. Above all, the author learned that the chances of success in
getting to affordable energy from SSP would be much greater than he had guessed
before he looked deeper into it, IF the right things are done. One of the most
important of these things would be truly competent work on reusable launch
vehicles (RLV).
In
this period, Ramon Chase provided the author with a kind of final report on the
activity that had been funded through ANSER on plasma hypersonic. In order to
show how much Ajax would really be worth, he developed a kind of final
assessment of cost to orbit under proper Ajax varieties, under conventional air
breathing hypersonic, and under a "near term" rockets with almost no risk representing
the lowest costs.
The
main conclusions at the end of this work were electrifying to the author:
1. With a best practice use of
rockets (using design principles from high speed aircraft), it would have been
possible to build "near term vehicles" able to reach $400/kg-LEO, within about
5 years, with at least 90% chance of success, relying entirely on proven
off-the-shelf technology for which a substantial database already exists. That
figure, $400/kg-LEO, is the same as Ivan Bekey's target from our 2000 workshop
for affordable SSP.
2. One key requirement for the
near term vehicle would be the use of a specific "hot structures" technology
developed by Boeing under the TAV and RASV programs. That was the only
technology ever developed on earth (that we knew about) which passed the
stringent three-way tests of ability to withstand re-entry conducted by the
only test facility in the US capable of such tests, located at WPAFB.
This eliminates the need for active TPS.
Furthermore, the serious CFD evaluations of air-breathing hypersonic at
3. The Boeing hot structures technology would soon become
seriously endangered. The key test article was already lost. Many key people
had retired, and many key designs were probably now just technical papers
stored in people's garages at risk of being lost forever.
4. The systems level design
developed by Chase himself also relied on unique skills and background and concepts,
which the author later checked in many ways. In the ANSER/Princeton project, it
was essential that the author be there to ask key questions, but he has often
worried about the implications of Chase aging and possibly retiring before the
world receives the full benefit of his understanding of this design.
Given
these facts, and given the funding situation at NSF, he decided not to fund a
penny more on hypersonic until and unless a way is found to rescue the hot
structures technology.ššš It is probably
best that the author does not describe all the follow-on discussions here.
Chase published a brief summary of his design in Aerospace America [20], but
also wrote many AIAA papers and technical reports with extensive details.
Perhaps one of those later discussions really
should be mentioned. On a visit to WPAFB, to hand off the final stages of the
ANSER project, the author had an opportunity to visit the testing lab there,
run by a prominent member of the IEEE Control Society. There were hundreds and
hundreds of test articles in view, including the latest advanced materials
under development by and for NASA. There was also a big "black room" of
materials the author could not see. The lab director was quite proud that this
is the test facility in the
The
author asked him: "Ray Chase tells me that out of all the many thousands of
articles you have tested here, there was only one which passed all the tests
for ability for repeated re-entry to earth - the Boeing RASV hot structures
article. Is that true?"
The lab director replied: "Yes, it is
true. Only one has passed the test. And any really serious candidate in the
In
September 2002, the Ohio Aerospace Institute hosted a joint technical
interchange meeting for JIETSSP. Among other things, SAIC presented a full
life-cycle cost analysis for various SSP designs previously developed under
Mankins' SERT program. The lowest cost design was projected to cost 17 cents
per kWh, if Ivan Bekey's technology parameters were achieved. This highlights
the importance of getting to $400/kg-LEO. But it also highlights the importance
of continued work to improve the designs, such as what we funded through
JIETSSP. At that time, it seemed that the best design involved the use of
lightweight lenses developed (and well tested) by Entech to concentrate light
up to 500X in space, and to focus it onto "sandwiches" of solar cell and
heat-to-electricity layers of new chips. Neville Marzwell of NASA JPL had
played a key role in developing that concept. Mankins felt that the cost could
be reduced to 10 cents per kWh by taking advantage of new heat pipe technology;
however, the funding ran out before the new design concept could be worked out,
tested and evaluated. About half the weight of those designs was for power
management and distribution; there have been huge breakthroughs in power
electronics in recent years, based on new chips and higher frequency power
transmission [14], butš there has been no
funding to go back and see how that could reduce the weight and cost of the
earlier designs.š At the time of JIETSSP,
the author also proposed a version of Space Fusion Systems (SFS) as an
alternative to develop in parallel with SSP; this would carry higher risk, but
would offer hope of much lower costs per kWh, if we meet the Ivan Bekey
technology specifications such as $400/kg-LEO. Kaya of Japan has developed
another interesting option, using well-tested phased array power beaming, which
is receiving serious funding in
In
2009 and 2010, more and more people in Congress began to understand that the
Apollo program for NASA was leading to vast cost overruns for expendable
rockets, which would be too expensive to allow us to afford a vigorous space
program. The Obama Administration cancelled these rockets. Lori Garver, a
former Executive Director of NSS, played a central role in representing the
Administration on these issues. Unfortunately, many
Of
course, the
The initial press coverage of the X37B seemed
very exciting to the author at first, but certain realities then intruded. The
vehicle is covered with a combination of "second generation shuttle tiles" and
of very hard carbon-carbon parts developed by ATK of Utah (perhaps essentially
the same company that Richard Nixon worked with). For the leading edges, they
are relying on a MATERIAL rather than a STRUCTURE, which means that the
material must do more work, and must be more expensive. The author does not
know how expensive it is to produce these materials in quantity, but he does
remember how even the easier thermoplastic C-C parts were extremely expensive
to fabricate before our breakthrough using technologies which ATK probably does
not understand [1]. The ideal path would perhaps be to combine the best passive
STRUCTURES - as in the Boeing TAV technology - with the best materials, and
even insert some Ajax-like fuel reformation in later stages of development. But
for now, cost per vehicle is just as important as reusability. It appears that
once again the dynamics of powerful lobby groups has intruded to eliminate what
had been the last best hope of humans in space.
There
is something very strange and ironic about the role of powerful forces from
Naturally,
the author has tried at times to discuss this with people he knows in Boeing,
but Boeing is a very large corporation. To a first approximation, it seems to
be a loosely coupled combination of two companies, one of which sells airplanes
to the private sector and leads the world in efficient low-cost mass production
of advanced vehicles, and another company, Federal Systems, which is
essentially a cost-plus contracting firm grounded in Washington. Chase has
estimated that it would cost only about $30 million to reconstruct the
successful hot structures test article, and to train new people and archive the
technology such that it would not be endangered again soon. In informal
discussion, Boeing has said that it would cost more like $150 million to do it
right, by exploring how it could best be upgraded by inserting new materials
(and of course infusing it all with modern mass manufacturing technology). But
that kind of support simply has not been forthcoming from anywhere. People the
author knows in other parts of Boeing have said that the key people remaining
in the TAV and RASV groups were scattered to the four winds just this year; we
are very close to losing the capabilities.
A
few months ago, the author was asked a question: "If Chinese investors and
Boeing were to agree to establish two really well-designed new consortia, one
for space solar power and one for launch services, what is the probability that
the launch services group could get to $400/kg-LEO within 5 to 10 years?" (Of
course, this assumes Chinese money, tight control of the launch services group
to respect US ITAR laws and Boeing IP, and benefits to all parties.) The
author's estimate was "70% now, and a lower probability for every year we wait.
It WAS 90% in 2002, but key people and documents have been lost or moved".
The author was also asked: "What about
the new China National Aerospace Plane project, CNASP, with design leadership
from Yong Yang of the
However, some technology has advanced,
and they have shown a remarkable ability to learn from the experience of
others. The current effort seems weak on the kind of bold, creative and
rigorous 'yang thinking" needed for success in this venture on their own, but
there is some possibility that help from
In
addressing the issue of international partnerships (like Boeing/China), the
author has said: "I hope we will not be like those proud people who beat their
chests, and say they will insist on having 100% of nothing rather than 50% of
something. That is a good way to become bankrupt".
But
at present, unless something new happens, humanity does seem to be on a path to
bankruptcy in this sector. There have been many times in the past when great
civilizations slowed down, could not keep up with new challenges, and then went
downhill. This time, if we do not develop this and other key technologies soon
enough, the author sees a substantial likelihood of a global downward course
which, because of new interdependencies and nuclear effects, might well result
in extinction of the entire species. Slow and well-considered paper studies
through the usual deliberative processes are on course to providing nothing but
an amusing inscription for our tombs.
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