Advanced Automation for Space Missions/Chapter 4.1
- 1 Chapter 4: Nonterrestrial Utilization Of Materials: Automated Space Manufacturing Facility
- 1.1 4.1 Introduction
Chapter 4: Nonterrestrial Utilization Of Materials: Automated Space Manufacturing Facility
The heavens have always been the subject of intense curiosity and longing, beckoning to our imaginations and, sometimes, to our desires for dominion over that which is not yet under human control. Recent American space exploration efforts represent only tentative steps toward increased human understanding of the Universe - indeed, lunar and planetary missions often have raised more questions than they have answered. Those in the forefront of space sciences believe that the ultimate horizons are as yet only dimly perceived. A substantial minority of the American public would like to see more effort devoted to deeper investigations of the planets, stars, and galaxies beyond Earth.
However, most people remain unconvinced that expanded activities in space gained apparently at the expense of other societal goals are worth the price (Overholt et al., 1975). Clearly, future large-scale American space projects should embody a fundamentally new perspective - an overall shift from the existing policy of (primarily) exploration to one of integrated and direct utility for mankind. Such a pragmatic space utilization program may demand extensive use of nonterrestrial materials and an ever-increasing dependence on automation in all its dimensions. The Nonterrestrial Utilization of Materials Team has explored the need for such a program, and has laid the foundation for future NASA technology planning by examining in some detail a space project having the potential for physical growth with continually decreasing net materials import from Earth.
A principal objective of the present study is to develop scenarios which show how, starting from current plans and capabilities, an extraterrestrial facility providing economic benefits for humanity can be established, maintained, and expanded in the near future. Ultimately, this permanent orbital factory will be dependent in large degree on nonterrestrial materials and autonomous robots programmed for advanced machine chapter 4 is to demonstrate the relationship between nonterrestrial utilization of materials and the growth of an orbital manufacturing facility beginning with a minimal "starting kit" of machines. The kit performs basic manufacturing processes necessary for facility expansion and the creation of a widening spectrum of the means of production.
This goal was chosen because only through the development of extraterrestrial resources can future space activities be pursued independently of terrestrial resource limitations and management constraints. The proposed scenarios for space facility maturation are essentially open-ended, so a variety of exploration and utilization options continuously become available once initial economic productivity is established.
The basic requirement explored in this approach to space industrialization is the establishment of two off-Earth facilities, one in space and one on the Moon. In this scenario, an Earth-orbital base will provide logistical support and production capability necessary for the creation of useful end products and its own expansion. A space platform should be established early, initially dependent on the Space Shuttle, as a demonstration of "starting kit" operation and advanced production methods. However, rapid factory growth necessitates the use of lunar or asteroidal resources. Therefore, a lunar processing and manufacturing facility (Dalton and Hohmann, 1972), possibly self-replicating (see chapter 5), is presupposed in the growth scenario.
The availability of nonterrestrial materials could make possible a decreasing dependence on Earth-based supplies. Growth of the Space Manufacturing Facility (SMF) subsequently would require no major additional Earth resource inputs. Given a supply of sufficiently inexpensive nonterrestrial materials, SMF output could be returned to Earth directly in the form of useful commercial products or indirectly in the form of solar power generation or satellite servicing.
The present analysis is explicitly guided by the goal of maximizing the use of automation and robotics during expansion of the processing and manufacturing facilities. Even in the early stages many operations can be conducted by remote teleoperators. As research in robotics continues, more and more system functions will be taken over by autonomous robots. While it is unlikely that the human presence soon can be completely eliminated, economic arguments favoring SMF deployment require the assumption of an increasing use of autonomous machine systems.
4.1.2 Rationale for the Utilization of Space
The American push into space, never fully backed by the public, appears in recent years to have slipped even lower on the list of national priorities (Lowman, 1975). The current unwillingness by the political leadership of the country to support space activities is reflected in the weakened budgetary position of NASA, the prime driving force behind the United States civilian space program. Major reasons for this lack of support include:
- A policy of piecemeal exploration
- An emphasis on limited-duration, "one-shot" projects
- Indirect rather than direct benefits achieved by space missions
- The view of human welfare as a byproduct rather than an explicit goal of space activity
- Too great an emphasis on purely scientific benefits
- "Selling" space to particular interest groups with insufficient regard for immediate public interests
- Too little public input in NASA planning.
The weak interest in NASA programs is, however, correctable. It must be established that major future NASA programs will be explicitly tied to the public welfare and that concrete, short-range benefits for individual members of society can and will be achieved. This may be accomplished either by demonstrating that an immediate threat to the American way of life can be averted through the implementation of a particular space program, or by showing that a mission will have a visible economic payback to the public.
Unquestionably the first method has the best chance of loosening the legislative purse strings. Indeed, the strongest public and legislative interest in space was expressed during the Sputnik crisis in 1958 (Overholt et al., 1975). A recent Woods Hole conference concluded that potential triggers for renewed efforts in space might be crisis-based. Among eighteen possibilities listed by panel participants were such events as impending asteroid collision with Earth, rapid changes in the polar icecaps, discovery of extraterrestrial life, some major accomplishment in space by another nation, or a credible military threat. Unfortunately, none of these possibilities suggest a positive planning process since by their very nature they occur unexpectedly (Sadin, private communication, 1980).
One externally generated crisis once thought to provide impetus for further space activities was the prediction by the "Club of Rome" of an impending shortage of critical terrestrial raw materials (Meadows et al., 1972; Laszlo et al., 1977). Subsequent researchers found significant flaws in the study, detracting from the Immediacy of the threat (Kahn, 1976: Science Applications, Inc., 1978) and eliminating an impending world food crisis as a major space mission driver.
Still, it must be recognized that "need" is a relative term. For instance, a country (such as the United States) fundamentally committed to economic growth and vitality can find its horizons of economic "need" closing in much faster than, say, a global community committed only to survival. This public perception may inspire a recognition of the connection between the profitability of space ventures and the impending decline of a way of life. The issue of "need" thus reduces to the question of how best to utilize both terrestrial and nonterrestrial resources to avert a fundamental threat to the American standard of living.
Consonant with the above motivational framework, major future space missions must be clearly directed toward the utilization of space for the distributive benefit of the American public, and be designed to avert erosion of national living standards. In addition, the existing economic climate of the U.S. must be taken into consideration: Each project must show a near-term, growing productive capability; it must take appropriate measure of national priorities; it cannot rely too heavily on capital investment; and, finally, national leaders and the public must perceive it as directly beneficial to their own interests. The proposed Space Manufacturing Facility is designed to meet each of the criteria established above.
The SMF mission utilizes resources not presently available for the clear and direct benefit of the American public. This benefit may include (1) construction of solar power satellite stations to generate energy for Earth, (2) manufacture of useful products on the Moon for terrestrial use predominantly from lunar materials, (3) eventual production of consumer goods in the SMF for Earth, employing the unique qualities of the space environment plus lunar or asteroidal materials, (4) utilization of processes unsuitable, unsafe, or otherwise desirable for application on Earth, and (5) using the SMF as a springboard for further space resource exploration and industrialization.
Near-term growing productive capability.
The Space Manufacturing Facility is intended to take full advantage of past, current, and future research in machine intelligence and robotics. Technological enablers now exist in automation, space transportation, and in the results from lunar research. Present competition in industrial robotics is intense, and rapid beneficial developments might be expected to occur even without NASA funding. Serious exploitation of robotics technology in an SMF scenario, however, will accelerate development and permit a growing productive capability from which immediate, near-term human benefits can be siphoned off. The proposed project is open-ended: Growth in productivity is expected with concurrent multiplication of the range of capabilities available, without infusing large amounts of additional capital.
The primary investment is for the establishment of two starting facilities, one on the Moon and one in Earth orbit. It is anticipated that near-closure (see chapter 5) will be achievable and that minimal human presence will be necessary. Interaction between lunar and Earth-orbiting components allows growth materials required by the orbital module to be supplied from lunar sources, thus greatly reducing supply costs. A major gain with respect to capital investment and production costs is that fewer materials must be flown up from Earth and that almost all the required on-site labor can be performed by automata.
Certainly the SMF generates a number of indirect benefits for the public. It opens new horizons of knowledge, advantages American industry in international competition, provides new technologies, and reasserts the U.S. position of leadership in space. However, the public relates only vaguely to such interests, if at all. The establishment of a solar power satellite, on the other hand, is of more direct and tangible value. This kind of SMF product could have direct impact on energy costs now borne by the public and could lead to a visible decrease of dependence on foreign energy supplies.
Standards of living and public perceptions.
If the capital investments required are accounted for, the proposed mission can help to stabilize the American standard of living and eventually permit it to continue to rise. Energy scarcity is widely perceived as the root cause of current economic difficulties, a viewpoint stressed repeatedly by the media. Rampant inflation and unemployment, justly or unjustly, are traced directly back to the cost of energy. Recently, however, it has become increasingly apparent that the issue is not simply energy supply but also energy cost. Given the education the public already has received, it should not require too much additional effort to make people aware that their own short- and long-term interests are well-served by the SMF. The poor economic climate actually may prove an added fiscal impetus for the mission rather than a restraint.
4.1.3 Summary of Chapter Contents
The study team focused its efforts on four areas related to the nonterrestrial utilization of materials:
- Material resources needed for feedstock in an orbital manufacturing facility (section 4.2)
- Required initial components of a nonterrestrial manufacturing facility (section 4.3)
- Growth and productive capability of such a facility (section 4.4)
- Automation and robotics requirements of the facility (section 4.5)
Section 4.2 presents an overview of energy and mass available in the Solar System, with special attention to those resources which may be available in the near future and to possible space materials processing techniques. A lunar-to-LEO shuttle system utilizing silane fuel and an Earth-based electromagnetic catapult are possible candidates for the transportation of raw' materials and feedstock to low Earth orbit.
Scenarios for establishing an initial orbiting manufacturing facility are developed in section 4.3. To provide some basis for determining the minimum number and types of machines which might be available for space manufacturing and for constructing an automated shop capable of creating additional industrial equipment, a survey of basic manufacturing processes was performed by the team. "Starting kits" were conceptualized which might be useful in creating an ever-widening set of manufacturing devices requiring minimal initial inputs and using solar energy, vacuum, zero-gravity, and robotics to best advantage.
Section 4.4 demonstrates the growth and production potential of the Space Manufacturing Facility using the material resources and starting kits described earlier. Near-, mid-, and long-term examples of product manufacture are developed. These outputs, including Shuttle external tank conversion to simple structures (near-term), electronics components fabrication (mid-term), and the creation of space platforms, pure glasses, satellites, and robots (long-term), are presented as representative samples of SMF growth possibilities.
Section 4.5 concentrates on mission automat;on and machine intelligence requirements for an SMF. Limitations and functional demands of robotics in space are detailed. with recommendations for future machine intelligence developments. Mission technology drivers in major areas other than automation and machine intelligence are briefly summarized. Finally, section 4.6 provides a general discussion of the implications for society, potential consequences. and necessary sociocultural and political prerequisites for implementation of a space manufacturing mission.