Domain: rotaryrocket.com
Stories and comments across the archive that link to rotaryrocket.com.
Stories · 3
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Improved Composites Manufacturing
JoeSilva writes: "I immediately thought this cheaper and faster process for manufacturing composite materials could really lend a hand to the goals of HyperCars a-la the Rock Mountain Institute folks, and Reusable Space Launchers a-la X-33/VentureStar, Roton, and others. The RMI folks have been advocating use of carbon fiber composites, but have noted that Aluminum has seen some favor with the Auto manufacturers, and one reason for that has been cost. The X-33 program was set way back due to a manufacturing failure in making what they claimed was the worlds largest carbon fiber composite fuel tank...in fact I recall reading that there was no AutoClave in the world big enough for the tank size for VentureStar. The X-33 was a smaller scale test vehicle...not a launcher. The new process can make whole boats and airplane fuselages." -
The High Frontier
Reader apsmith contributed this review of Gerard O'Neill's The High Frontier, a book now nearly a quarter century old. The author's dream of an upwardly mobile Earth population remains largely unrealized, though if O'Neill were alive today, he might be gladdened that there is at least one long-term orbiting home in place. The High Frontier author Gerard K. O'Neill pages 326 publisher (1989 edition) Space Studies Institute Press rating 10 reviewer apsmith ISBN 0962237906 summary O'Neill outlines how to colonize near space with little more than boring 1970s materials and engineering know-how, with boot-strap colonies of thousands of peopleprocessing moon and asteroid dust in high-earth orbit. The Big Idea Continued growth in material well-being and freedom for humanity is only possible through colonization of space; O'Neill outlines how to do it with little more than boring 1970's materials and engineering know-how, via boot-strap colonies of thousands of people processing moon and asteroid dust in high-earth orbit. The only problem is the seed capital to get started; his initial $100 billion was clearly an over-estimate - a later estimate brought the startup costs closer to $7 billion. Even more important we really should now have the resources and motivation (global warming!) to make it happen. There is a new 2000 edition with additional material from other authors.
The Scenario: In 1969 Princeton physicist Gerard O'Neill organized a weekly seminar for the advanced students in his freshman physics class. It was Apollo's heyday, but also a time of deepening skepticism in the benefits and relevance of science and technology. Both the Cold War with the Soviets and the hot war in Vietnam were at their height; pollution seemed to be worsening everywhere; serious people were arguing that humankind was already overstepping Earth's carrying capacity, and it was time to retrench. In this climate O'Neill asked his students:"Is a planetary surface the right place for an expanding technological civilization?"
And despite what Isaac Asimov called our "planetary chauvinism", O'Neill and his little group came up with strong arguments and designs for artificial colonies in high orbit or free space, well away from planetary surfaces. O'Neill was so taken with their enthusiasm for this that he committed a good deal of his spare time over the next several years to developing the ideas and trying to get them published. Along the way he enlisted a young MIT student named Eric Drexler, and colleague Freeman Dyson, among a small group of supporters. Worldwide publicity finally arrived in May 1974, when the NY Times sent a reporter to the small conference O'Neill had organized on this new topic of "space colonization".
Three years later came "The High Frontier", O'Neill's main publication for a popular audience on the subject. In his 1993 obituary Freeman Dyson said, "The High Frontier... established O'Neill as a spokesman for the people in many countries who believe that the settlement of space can bring tremendous benefits to humanity ...."
Repeated throughout the book is O'Neill's goal: "the humanization of space", by which he means in part the capacity to move the bulk of humanity off this planet and into colonies with resources vastly greater than what the Earth can provide. These colonies would be more than self-supporting; their first great contribution would be in construction of solar power satellites from lunar materials, allowing the nations of Earth to vastly expand their energy resources in the most environmentally sound fashion possible. Earth's surface captures only a tiny fraction of the solar energy available; something like 30 times what Earth receives comes through even the relatively narrow confines of geosynchronous orbit; another factor of 100 times as much energy is available inside the Moon's orbit where the "L5" or "high" orbits for the colonies are suggested.
O'Neill goes through in some detail what it would take, using the capacity of NASA's then-planned space shuttle, to first set up an initial mining station on the moon, which would then launch hundreds or thousands of times more mass to high orbit. The one new technology O'Neill relied on was his "mass driver", an electromagnetic acceleration system used both on the lunar surface to dump raw materials into space, and as a propulsion system somewhat similar to the electromagnetic "ion drive" NASA is now using on its Deep Space 1 mission, and of course related to the electromagnetic particle accelerators O'Neill worked with at his real job. O'Neill and colleagues even put together several "mass drivers" out of spare parts to test what accelerations were feasible -- even the first model achieved over 30 g's.
The centerpiece of the book is the design of the colonies themselves, constructed for the most part out of lunar material. These are the hollow spheres or cylinders, which O'Neill refers to as "Islands", rotated so as to provide a land area with artificial gravity. There's no fancy technology needed, despite what you might expect reading Clarke's Rama novels, or Greg Bear's Eon, or countless others. The magnitude of Island One, a colony designed for some 10,000 people, is well within the scale of many artifical structures we have built here on earth; O'Neill compares it to shipbuilding in particular. O'Neill's materials are aluminum alloys or even steel; no need for carbon fiber composites here (and the Moon is a little low on carbon anyway). The colonies provide comforts similar to home, with terraced apartments, rooftop gardens, forests and rivers and recreational areas. Lighting is provided through a somewhat complex system of mirrors, baffles, and ordinary glass windows - no need for a central "plasma tube"! Radiation shielding is the usual six feet of slag or lunar dirt.
The book is chock-full of great ideas that seem to make the whole scheme obviously practical. Did you know the space shuttle cargo bay has roughly the same capacity as a DC-9 airliner? In principle our current space shuttles could be used to ferry over a hundred passengers into space at a time; O'Neill estimates that even a limited shuttle fleet could get close to a hundred thousand people into low earth orbit every year (of course that was back when NASA thought it would be doing 60 shuttle missions a year). O'Neill was sure that other better ways of getting into low earth orbit would come along; the next few years should be very interesting in this regard with new launch systems from Kistler Aerospace, Rotary Rocket, etc. supposedly in the works. With O'Neill's reasonably optimistic scenario, we would have hundreds of millions of people in these colonies in 35-50 years. Sounds outrageous? A hundred years ago most people thought it was impossible to fly something heavier than air, but now airlines routinely handle hundreds of millions of passengers every year.
What's Good? Just about everything -- I'd heard about this book probably since I was in grade school, but never got around to reading it until now. It's the clear foundation for any logical expansion of humanity into space; all we need to do is get with the program! O'Neill founded the Space Studies Institute to gather private donations to spur further research into the whole scheme, which it has done very extensively. What's Bad? Why hasn't it all happened yet? The 1989 edition contains a newer appendix by O'Neill with the following quote that sums up at least part of the problem: "In 1973 the U.S. space program had been fifteen years ahead of all others. By 1988 that lead had been thrown away." But O'Neill's prophesying was somehow also at fault. With such huge untapped resources, why hasn't Exxon or Mobil, or General Electric, been leaping at the chance to invest some of their spare capital to make a killing? Maybe they're just too clueless about the possibilities here? Or maybe they've made a rational judgment to be second or third, not first on something as apparently risky as this? Somebody has to do it first, and O'Neill in his 1989 comments at least seems to have lost faith in NASA and its over-cautious contractors to get the thing started. So who will it be? What's in it for me? There seems a good chance space development will be "the next big thing" after the Internet has run its course through our lives. After all, we still need material resources to do the things we want to do. Earth's population is still increasing, and its resources really are limited. The threat of global warming traces almost entirely to our burning of fossil fuels for energy. If we don't get started on a long-term solution now, when will we? This book is still the clearest rational outline of why, and how, space development makes sense. Plus, who wouldn't want an apartment on one of those "islands in the sky"?"
You can purchase this book at Fatbrain. -
Publicly Funded Competition For NASA?
Wigs writes: "There's a nice article on spaceprojects.com about NASA's current competition, or rather the lack of it. From the article: 'The Microsoft antitrust litigation, as well as the consumer benifits resulting from AT&T's break-up, have substantially raised public awareness about the negative impact that monopolies can have on society. Many people who know much about NASA distrust it as well ... It seems NASA would benefit from having publicly funded competition, resembling what Japan's two competing civilian space agencies have.' I've heard that companies like United Space Alliance have looked into the possiblity of purchasing a shuttle, but have been shot down by NASA officials. Other companies looking to get into the single stage to orbit competition are Rotary Rocket, Kelly Space, and Pegasus (actually 3-stage). However, these are all private companies. This article discussing public funding, namely the National Science Foundation."