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THE HIGH FRONTIER® NEWSLETTER
VOLUME XV ISSUE l JANUARY/FEBRUARY 1989
Power From Space
Gerard K. O’Neill
(Reprinted from The Washington Times, Wednesday, December 7, 1988)
Our space program was at its best when given strong direction to reach a clear national goal. For 15 years it has lacked that direction and, with the exception of some fine space science, we have lost those years.
We scrapped our excellent fleet of rockets and spent our effort on the highly experimental Space Shuttle. While the Shuttle is a technological triumph, it can loft only 20 percent of the weight to orbit that our Saturn 5 could in 1968.
We are in danger of losing decades more. The space station would repeat our Skylab, 25 years later, somewhat bigger and better and at vast expense.
There is also talk of a US-Soviet manned mission to Mars, a mission whose every scientific value could be achieved at far less cost by robotic spacecraft. The political experiment has already been tried and failed. The ApolloSoyuz linkup in 1975, much heralded, helped not at all to improve US-Soviet relations then or since.
Either alternative might be acceptable if the United States enjoyed unchallenged economic supremacy and could afford unlimited waste. But the real world of today is harsh, and the US space program must be judged in that reality. Japan’s gross national product per capita has already achieved rough parity with our own. If we continue to lose the race to increase industrial productivity, even the total GNP of our nation will fall behind Japan’s. Meanwhile, our industries are sold abroad.
In that real world it makes no sense for us to spend billions on empty political gestures. The space.program of the United States must be constructed with clear economic goals. It must be designed to address the critical problems of US economic survival and growth in a competitive, clever, hard-working world.
As responsible citizens of the world, we should also press for technologies that are clean, safe, productive and peaceful.
The most insidious global environmental problem is the dumping of more than 5,000 megatons of carbon dioxide into our atmosphere every year, from the ever-increasing burning of fossil fuels. The greenhouse effect of that burning is already close to producing worldwide climate changes.
There is just one space goal which addresses both our national economic needs and the most pressing worldwide environmental threat. It is the construction in space of solarpowered satellites to supply clean electric energy for the Earth. High technology is required,but no scientific breakthroughs. Arrays of solar cells would be assembled in the 24-hour, equatorial orbit. Each station would remain above a fixed point on the ground, as do communications satellites.
In that orbit, sunshine is nearly permanent, so energy storage is unnecessary. Solar energy would be converted to electricity by the solar cells, and from electricity to low density radio waves for transmission to the ground. There, antennas in fenced-off regions would convert the radio waves to ordinary electricity, to be fed into national electric grids.
The power-satellite concept has been studied in detail for more than 20 years. A demonstration system transmitted more than 30 kilowatts of power over a mile. Laboratory tests showed that power can be transmitted from space to Earth at an efficiency above 54 percent, quite high enough for economic success.
Satellite power would substitute for the burning of fossil fuels. It is not nuclear and would not produce radioactive wastes. Analyses over the past 10 years have shown that satellite power is environmentally sound and can compete economically with coal-burning or nuclear plants, on one condition: that the materials for the power satellites come from the Moon, whose gravitational grip is less than 5 percent of the Earth’s. The right materials are there: aluminum, silicon, oxygen and iron.
A US industry in space to build power satellites for all nations would tap a world market which could exceed $250 billion a year. That figure is based on the cost of ordinary power plants, and on the annual needs for power plants wordwide.
Government endorsement of a commercial program to reach that goal would draw private capital investment, would justify expanding space science and NASA’s technology programs, and would deserve the continuing support of the public, Congress and successive administrations.
Gerard K. O’Neill
VICE PRESIDENT’S COLUMN
I am pleased to report a very successful trip to the Soviet Union in late December. The trip culminated in the execution of two agreements between the Space Studies Institute and the Moscow Aviation Institute, which will lead to eventual joint projects between our organizations. We will have more details on the trip and our new relationship in future issues of Update.
In This Issue
This month’s issue of Update is devoted primarily to a summary of the new NASA Office of Exploration Report entitled “Beyond Earth’s Boundaries.” The Office of Exploration (known in NASA as ‘Code Z’) looked at four scenarios last year for future manned space activity.
While we are pleased to see this forward thinking report, it seems to us that our space program should have a definite objective and purpose, in addition to, “boldly going where no man has gone before.”
Dr. O’Neill’s accompanying article entitled “Power From Space,” which appeared as an op-ed piece in the Washington Times, provides a good summary of our feelings in this matter.
NASA also has an interest in space power as a goal for future missions and is now assembling a “Lunar Energy Enterprise” case study which will look at three types of power from the Moon, including collecting energy at the Moon’s surface for transmission to Earth, mining Helium-3 for terrestrial fusion and constructing solar power satellites from lunar materials.
Congratulations to Senior Associates, Peter Diamandis, Todd Hawley, Christopher Mau and Robert Richards. They recently received a “Laurel” in the annual awards issue of Aviation Week and Space Technology magazine. Peter, Todd, Chris and Bob received
their award for their work in creating the International Space University. All of us at SSI join in commending them on a job well done.
Lunar Prospector Special Report
Along with this issue is a special document detailing SSI’s Lunar Polar Prospector research and plans. 1989 will be a pivotal year for this work, and it is appropriate that you who have made it possible should get a thorough briefing on the subject.
Thank you for your support.
A copy of the complete report, “Beyond Earth’s Boundaries,” is available free of charge by contacting Beth Craig, NASA Headquarters, Code Z, Washington, DC 20546. Note: the first printing of this report was exhausted. It is in its second printing and there may be a delay in getting the report to you.
Pathways to Human Exploration Beyond Earth’s Boundaries
The following is a summary of a report prepared by NASA’s Office of Exploration.
An extensive range of possibilities exists for human exploration and development ofthe Moon and Mars. To organize and systematically examine a full spectrum of options, we identified three strategies, or alternative pathways, for study this year. Each strategy presents particular opportunities for satisfying defined exploration themes and objectives. In the coming years, additional pathways will be developed to expand the set of options.
The first strategy addresses human expeditions, emphasizing a significant, visible, successful effort to establish the first human presence on another body in the solar system. The expeditionary pathway would lead to exploration without the burden and overhead associated with lasting structures and facilities. This pathway has been explored for missions to Mars and its moons.
Establishing a science outpost, the second strategy, emphasizes advancing scientific knowledge and gaining operational experience by building and maintaining an extraterrestrial outpost as a permanent observatory. Such a facility, located far from the obscuring effects of Earth’s turbulent atmosphere, would tremendously enhance our long-term astronomical studies. The experience gained in the process would serve as foundation for establishing a permanent human base on another planetary body. This pathway has been explored for a mission to the Moon.
The third pathway, evolutionary expansion, would sustain a methodical, step-by-step program to open the inner solar system for exploration, space science research, extraterrestrial resource development, and ultimately, permanent human presence. This strategy would begin with an outpost on the Moon and progress to similar bases of operations on Mars and its moons.
Phobos Case Study Scenario
An expedition to Phobos would employ a ‘split/sprint’ transportation approach: a cargo transport carrying the Phobos exploration equipment, Mars rovers, and the crew’s return chemical propellant would be launched on a minimum-energy trajectory early in the 21st Century, perhaps in 2001. In approximately nine months, the cargo vehicle would be placed in Mars orbit to await the piloted spacecraft. About 10 months later, a second spaceship carrying a crew of four would be launched from Earth on a high-energy, sprintclass trajectory, which requires about nine months to reach Phobos.
The piloted spacecraft would rendezous with the cargo transport in Mars orbit. Two crew members would then transfer to an ‘excursion’ vehicle and depart to explore the surface of Phobos. During that time, the crew on Phobos would make observations, conduct experiments, explore, and gather samples. The two crew members who remain in the orbiter would teleoperate, or remotely control, rovers which would explore and gather samples from the surface of Mars. After spending about 20 days at Phobos, the excursion crew would rendezvous with the orbiting vehicle. The Mars surface samples would be launched for return as well, and after 30 days in the Mars system, the entire crew and their supplies (using fuel transferred from the cargo vehicle) would return to Earth. The total length of the mission would be a little more than 14 months.
Mars Surface Scenario
Three separate expeditions to Mars are envisioned; for each, a split/sprint transportion approach would be employed. For the first expedition, a cargo transport carrying the landing vehicle (including the Mars surface habitat, exploration equipment, and the ascent vehicle) and the Earth-return chemical propellent would be launched on a minimumenergy trajectjory early in the 21st Century, perhaps in 2005. Upon arrival, this vehicle would be placed in Mars orbit to await the piloted spacecraft. About three months later, a spaceship carrying eight crew members would be launched to Mars on a high-energy, sprint-class trajectory.
After an eight-month journey, the piloted craft would rendezvous with the cargo transport in Mars orbit. Four crew members would transfer to the Mars landing vehicles and depart for a 20-day exploration on the Martian surface. The other four crew members would perform the propellant transfer from the cargo piloted spacecraft, conduct Marsorbital science, and monitor and assist the activites under way on the surface of Mars. After approximately 30 days in the Martian system, the surface crew would rendezvous with the orbiting parent spacecraft and subsequently depart for Earth, arriving six months later. The total length of the mission would be a little more than 14 months.
Cargo/piloted vehicle pairs would again set out for Mars during the next two launch opportunities. Piloted excursions to Phobos and Deimos would also be part of the threemission set. Each of the three Mars missions would include human and teleoperated robotic exploration, and each is planned to visit a different landing site on the Martain surface.
Case Study Requirements
The Earth-to-0rbit transportation needs for expeditions to Mars are significantly greater than those required to travel to Phobos (Case Study 1). Because of the large scale of these missions, a low-Earth orbit transportation depot would be needed to assemble and fuel spacecraft, to transfer crew members to the Mars vechile, and to recover them upon return to Earth orbit. Technologies for in-0rbit assembly operations, long-term storage of cryogenic propellant, and methods for transferring propellant while in the orbits of both Mars and Earth must be developed. Mars expeditions would also require significant new technologies, such as advanced propulsion systems and aerocapture techniques at both Mars and Earth.
After a long journey, the crew would land on Mars, which has a gravity field that is about one-third that of Earth; they will need to be physically fit and ready to explore. The length of the mission and the variation in gravitational conditions raise important life sciences issues. A program of research is required to lead to a decision on whether the mission can be carried out safely within a zero-gravity spacecraft, or whether the provision of an artificial gravity environment is necessary. Ifartifical gravity is required, the acceptable characteristics (gravity level,rotation rate) must be predetermined.
Robotic precursor missions are required to better understand the Martian environment for reasons of human safety, lander safety and operations, optimizing the scientific return, and providing end-to-end technology demonstrations for human missions.
This case would require a fast-paced development schedule in order to allow an expedition by the later part of the first decade of the 21st Century. Research for determining whether zero gravity or artificial gravity should be used may be the major pacing item for the schedule.
Astronomers have long been frustrated by the fact that, even with the most sophisticated telescopes on Earth, many of the objects that they wish to observe are extremely difficult to see because of the impediments generated by Earth,s atmosphere. Telescopes in Earth orbit offer substantial improvements in viewing conditions, but an observatory on the Moon could be orders of magnitude more sensitive, as larger, more stable instruments and arrays can be emplaced.
The objective of this case study is to understand the effort required to build and operate a long-duration human-tended astronomical observatory on the far side of the Moon. The Moon,s far side, which is quiet, seismically stable, and shielded from Earth’s electronic noise, may be the solar system,s best location for such an observatory. The facility would consist of optical telescope arrays, stellar monitoring telescopes, and radio telescopes, allowing near-complete coverage of the radio and optical spectra. The observatory would also serve as a base for geologic exploration and for a modest life sciences laboratory.
Background and Strategy
The Lunar Observatory would build on the legacy of the Apollo Program, through which we learned that human beings can visit and work on the surface of the Moon. This case represents a substantial step forward, to build and operate new and larger types of instruments and extend the range of exploration.
The Moon is a keystone for planetary science. Understanding gained from Apollo investigations forms the basis for interpreting the history of other planetary bodies that have only been studied remotely by robotic missions. That history is an essential element in understanding the early history of Earth, as well as providing insight into the process of evolution of all the solid bodies of the solar system. As we continue to refine our case studies, we will work intensively with the scientific community to validate and refine our understanding of the opportunities to advance science through an observatory on the Moon.
This case attempts to maximize scientific return using a minimum amount ofpermanent support facilities. In addition, it would provide an opportunity to gain experience in building and operating surface science systems, specifically as interim steps toward establishing a permanent human base.
Building up the observatory would include both robotic and piloted missions, with the robotic spacecraft delivering equipment and supplies to the lunar surface. The number of set-up missions per year was limited to two, in order to minimize infrastructure requirements and associated investments.
The scenario for the Lunar Observatory assumes that four missions to the Moon’s far side would be required to set up an operational facility. The four flights would consist of one cargo and one piloted mission per year, in two successive years, perhaps beginning as early as 2004. These four missions would be followed by one combined crew I cargo mission per year thereafter.
Each piloted spacecraft would carry a crew of four. The round trip would be fewer than 20 days, including a maximum of 14 Earth days spent by the crew on the lunar surface. No permanent habitat would be set up; because of the short stay time, and also because of the fact that non-servicing missions will visit different sites, the crew would live in and work out of the lander vehicle on each mission.
The base would be crew-tended, but not permanently occupied. Using one or more unpressurized rovers capable of traversing 10 kilometers, the crew would set up experiments and service and maintain equipment during one lunar day (14 Earth days) per visit, with no requirement to occupy the facility during the lunar night. The number of instruments, and their level of sophistication, could increase with time as our experience grows and the outpost is furbished and maintained.
Nominally, the astronomical facilities would require human-tended servicing only once every three years after they become operational. In the off-servicing years, two crew members would make several exploratory trips in the unpressurized rover, while the other two crew members would remotely control automated rovers traveling larger distances.
Case Study Requirements
A facility in low-Earth orbit would be necessary to support transfer vehicle and payload assembly operations, including element construction and checkout, propellant storage and transfer, and payload servicing. The transportation strategy also calls for the use ofaerodynamic braking (aerocapture) into Earth’s orbit as the crew vehicle returns to the transportation depot.
For the most part, the technology requirements for the Lunar Observatory focus on activities on the surface of the Moon. Vehicles for transporting the crew on their IO-kilometer trips must be developed. (Such vehicles will be larger than, but functionally similar to, the Apollo lunar roving vehicle.) Some of the telescopic systems would require specialized equipment for their emplacement. To operate the facilities and the rover, an electrical power plant must be constructed and maintained.
To establish the Lunar Observatory, an adequate far-side site must be characterized and certified for landing. This would require a precursor robotic mission such as the Lunar Observer already under study by NASA’s Office of Space Science and Applications.
Lunar Outpost to Early Mars Evolution
One of the recommendations of the National Commission on Space was that a ‘bridge between worlds’ be built in the inner solar system to establish human presence on the Moon and Mars, combining a number of different objectives in the process. An underlying goal is to learn to live, first off the lunar land, and eventually the Martian land as well. This case study seeks to realize that goal, by building a capability that would lead to a nearly self-sufficient, sustained human presence beyond low-Earth orbit. The evolutionary approach would provide the impetus for a broad range of technology advancement, evolutionary experience in outpost construction and habitation, use of local resources, and the development of facilities that would stimulate further growth.
Background and Strategy
This approach to expanding human presence into the inner solar system addresses a variety of objectives: science, resource development, technology stimulation, and commercial benefits. Through a series of progressive steps, Earth’s Moon, and then Phobos, Deimos, and Mars would be thoroughly explored and exploited.
The intent of the missions proposed in this case study is to develop and sustain a human presence beyond Earth orbit; this would be accomplished in two parts. First is the establishment of a permanently staffed facility on the lunar surface. This outpost would provide a living environment in which to conduct partial-gravity research, gain experience in long-duration human planetary missions, and initiate the use of local resources. Lunar oxygen, for example, could support the lunar base life-support system, and could be used for rocket fuel for further expansion of exploration. Another interesting possibility is that helium-3, which is available in commercially useful quantities on the Moon, may be a potential fuel for future nuclear fusion reactors on Earth. This possibility bas been initially examined and found to be promising, and will be pursued more intensively in the future.
When the lunar propellant production is secure, the strategy would progress to human flights to Mars and the establishment of an outpost there. A capability for producing fuel from extraterrestrial resources would then be developed on Phobos or Deimos in order to further reduce costly requirements for transporting propellant through space. After the first three expeditions, piloted flights could continue as frequently as every 26 months, the time cycle for Earth-Mars launch opportunities.
Beginning early in the next century (approximately 2004), a series of piloted and cargo flights would embark for the Moon. The crews would travel to the Moon aboard chemically propelled transfer vehicles, whereas the surface equipment would be transported by a cargo vehicle that uses nuclear electric power. Several years would be spent in constructing a permanently staffed surface facility. Experience would be accumulated in all aspects of longduration human planetary habitation: life sciences, psychological effects and human dynamics, exploitation of natural resources, and scientific exploration. One goal of the base would be to produce, from the lunar soil, liquid oxygen needed as rocket fuel for subsequent Mars flights.
Although each case possesses its own unique attributes, some characteristics can be compared directly. For example, the annual mass to low-Earth orbit delivery requirement is important, since it directly affects the nature of necessary Earth-to-orbit transportation systems and Earth-orbital support facilities; furthermore, it is a first-order indicator of cost. Figure 1. (see page 4) illustrates this requirement for all four case studies, along with the approximate annual number of separate heavylift launches. The figure demonstrates that large peaks in mass, corresponding to the year chosen for launch, characterize expeditions. In contrast, both the Lunar Observatory and the Lunar Outpost to Early Mars Evolution cases are characterized by steady rates of much lower magnitude. All cases, however, require large total amounts of mass to be lifted to a low-Earth orbit.
Lunar Outpost to Early Mars Evolution
The evolutionary case study demonstrates the benefits to be accrued by using extraterrestrial resources in a long-term, sustained program. Both Mars cases – the expedition and this evolution – send three piloted flights to Mars, but this evolutionary case could accomplish a Mars mission using 30 percent less mass to low-Earth orbit. The evolutionary approach appears feasible with a sustained annual mass investment that is much lower than the surge required for a direct Mars expedition; however, this savings may be offset by the required investment in facilities on the Moon.
Much detailed analysis and refinement of this concept are required, especially concerning the necessary investments in technology, advanced transportation vehicles, and surface systems, before the true benefits of extraterrestrial resource use can be accurately evaluated.
The Moon can also be used as a “learning step” for exploring Mars. The lunar environment provides an opportunity to learn to live and work on another world, and to adapt to the confined, hostile environment of space. With all the unknowns associated with longterm human exploration, the Moon offers a partial-gravity extraterrestrial research base only three days’ journey from Earth, and can be used as a base for developing knowledge of what is required for a long-duration mission to Mars.
Although we have really only begun to develop and analyze this case, it shows considerable promise for scientific and exploration benefits and opportunities, as well as having the budgetary and policy advantages of a reduced and essentially constant annual requirement of resources. In the coming year, this evolutionary strategy will be analyzed in greater detail.
• A HEAVY-LIFT TRANSPORTATION SYSTEM must be pursued and targeted for operational readiness by the turn of the century. The capability to transport large quantities of mass (equipment, propellant, and personnel) to low-Earth orbit is essential. To meet our launch needs in the middle to late 1990s, some level of interim augmentation to our existing capabilities is required as well.
• AN ARTIFICIAL ORAVITY RESEARCH PROGRAM must be initiated in parallel with our zero-gravity countermeasure program if we are to maintain our ability to begin exploration in the first decade of the next century. If an artificial gravity environment must be provided, the accommodation of such facilities will have a significant impact on mission configuration. Therefore, this augmentation to our life sciences research program must be made by 1990, providing an answer by 1998, to allow human spaceship design to commence.
• AN ADVANCED DEVELOPMENT/FOCUSED TEST PROGRAM must be planned for initiation with the selection of the program pathway. It is essential to understand the performance and capability of selected new technologies, such as aerobraking, cryogenic fluid handling in space, closed ecological life-support systems, advanced fractional gravity spacecraft prototypes, and nuclear power systems. Experience and proof of concept in these areas are critical to a decision to proceed with the development of a specific initiative.
America’s civilian space program stands at the threshold of a new era of exploration, discovery, and enterprise. We can, and must cross that threshold, and begin to build the foundation that will allow us to break free of Earth’s boundaries and soar into the worlds beyond.
©space studies institute
NEXT: 1989 March-April (Space Debris, Soviet SSI)
SSI Newsletters: 1989 January February
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