SSI Update December 2007

January 10, 2008

Author: admin

The fourteenth SSI Conference on Space Manufacturing will be held at the Institute for Advanced Study in Princeton on April 19 and 20, 2008. The session chairs are responsible for the papers in their sessions. The sessions and chairs are:
Conference Chair: Prof. John S. Lewis
Space Manufacturing, Chair: Prof. Niklas Jarvstrat
Space Resources, Chair: Prof. John S. Lewis
Robotics, Chair: Prof. William “Red” Whittaker
Space Solar Power, Chair: Col. Michael “Coyote” Smith
Space Transportation, Chair: Prof. George Dyson
Closed Environment Life Support Systems, Chair: Dr. Lee Valentine
Economics, Chair: Dr. Klaus Heiss
Special Evening Session: Space Solar Power; the Space Solar Alliance for Future Energy
Poster session: Dr. Roger O’Neill
Recently the National Security Space Office of the Department of Defense, NSSO, under the leadership of General James Armor, began a serious study of Satellite Solar Power. The NSSO began the effort because the armed forces need to supply forward bases with electrical power and satellite solar power appeared likely to be economically competitive with the present cost of electricity at bases in Iraq. The NSSO is very interested in long term energy security for the United States and its allies. It would like to develop satellite solar power to prevent future wars over energy resources. No entity in the federal government has been charged with power satellite development and, excepting the NSSO, none has made any effort to promote it. The NSSO office would like to transfer responsibility for powersat development and construction to the private sector as soon as possible. They see the possibility that critical technologies will be classified secret and so become unusable for civilian purposes.

The study leader, Col. Michael Smith, asked for SSI’s input because our researchers have done much of the recent space solar power research and because SSI maintains the only full documentation of the extensive Satellite Solar Power studies performed by the government and its contractors from 1977 until 1981. Col. Smith is the chair of the Space Solar Power session at the upcoming Princeton Conference. SSI Senior Advisor John Mankins and SSI senior researcher Prof. Marty Hoffert have been major contributors to the ongoing study.
SSI is making an effort to have the space resources option considered as the prime beneficiary of any development money that may become available, since it still appears to offer the lowest cost option for energy supply to the Earth. This effort will be a tough battle, especially since the Earth-launched option clearly has the lowest technical risk and the benefits of using space resources are unclear without a demonstration. SSI will need to organize a study, like the “Low Profile Route to Space Manufacturing” study we performed in 1981, to reduce uncertainties in the cost and technical risk of using space resources to construct power satellites. There are many options for energy conversion in satellite solar power stations and many architectures. It is too early to specify an architecture because we do not know enough about costs and risks for various options to decide.
SSI is now in the unenviable position of shouldering the responsibility for the critical technology development for space industrialization and space settlement. Mike Griffin, the NASA Administrator, has lately been talking about space settlement and space resources but has no program to develop the technology necessary to achieve either. There are three critical areas of research for which no good solutions have yet been demonstrated. The first is cheap launch; another is the cost-effective conversion of space resources into economic goods, and the last is closed environment life support systems.
The elite engineering community has understood for decades that affordable space transportation is possible. Eugen Sanger analyzed the economics of low cost space transportation systems more than forty years ago. None of SSI’s plans to build clean satellite solar power stations and space colonies will be possible without a drastic reduction in launch costs. Assuming that all the power satellite components are launched from the ground, energy from space becomes economically competitive only at prices per pound to low Earth orbit of between one and two hundred dollars per pound. If the Moon is to be the source of the power satellite material, then it is possible that somewhat higher launch costs may allow economical power satellite construction.
A launch price below one hundred dollars per pound appears achievable with combustion rockets. An empiric rule is that a mature transportation system has total costs that are three to five times the cost of propellant. A fully reusable combustion rocket powered orbital transport should have propellant costs of about fifteen dollars per pound, for a total transportation cost of 45 to 75 dollars per pound. That cost per pound is well below that required to build a profitable power satellite system.
The likelihood of success in obtaining launch cost low enough to allow market elasticity to engage now appears great. SpaceX expects to cut the cost of launch by a factor of three within five years. The critical engine technology now seems to be in hand. By avoiding range services and using an aircraft first stage, AirLaunch, which has also had success in engine development, may offer an additional factor of two cost reduction. XCOR Aerospace plans an additional larger, reduction within ten years. XCOR has developed safe, very long life, high performance and reliable rocket engines as well as very lightweight highly reusable composite LOX tanks. There is a large amount of engineering development to be done in aerodynamics and thermal protection systems before flying a manned orbital system. The good news is that the suborbital space travel business appears to be lucrative enough to support the development of a fully reusable, manned orbital transporter. Much of SSI management’s time in the past sixteen months has been spent successfully helping such New Space companies raise investment capital. We are glad to see Armadillo, Blue Origin, Masten and XCOR flying low cost reusable rocket systems.
Next is the technology of closed environment life support systems. In the US, SSI has been alone in working on the most difficult of the technical challenges, that is recycling crop waste and sewage into plant nutrients. That is the critical technical challenge requiring solution before a fully closed life support system can be relied on to support human communities off the planet. With SSI support, Professor Bill Jewell spent most of last summer designing a CELSS system that relies on biological systems to recycle sewage and crop waste. He investigated the nitrogen cycle and designed and analyzed a concept using biological nitrogen fixation. The crop waste and sewage handling subsystem is designed to produce quantities of methane and other byproducts so that this system, if installed on a dairy farm with about five hundred cows, should be a profitable operation. (See Sustainable Water in Closed Biosystems: Preliminary Design Considerations by William J. Jewell – 2001.) It would be best from SSI’s point of view if we were able to pay for this critical subsystem of the CELSS project out of profits made on such an installation. Professor Jewell believes that there should be a substantial market for the energy provided by the crop waste disposal subsystem. His plan is to use the methane for process heat and to generate electricity with a fuel cell. We are still engaged in the search for a suitable farm.
Another critical path technology is obtaining engineering materials from space resources. We have known for thirty years that the critical missing technology for building power satellites and space settlements is process technology for lunar or asteroidal resources.Unless we develop suitable processes to yield cost effective engineering materials from space resources, the pace of space development will be slowed when we finally do have low cost access to space.There is little new work going on in this area. SSI sponsored much of the work done to date on obtaining engineering materials and propellants from non terrestrial sources. Professor John S. Lewis of the University of Arizona has taken the position of Vice President for research at SSI, beginning in June 2007. He is developing a research plan to devise methods for making materials for construction of space structures from space resources. Professor Lewis is particularly interested in asteroidal resources. These bodies do provide a wider array of potential materials than does the Moon, however, none has yet been discovered in an orbit that might render its resources cost effective given present space transportation options.
SSI co-sponsored the Planetary Defense Conference at George Washington University in March, 2007. SSI is interested in the discovery of asteroids in orbits that are economically accessible from Earth. None have been found so far, but the rate of discovery is about to undergo a radical increase as the Panoramic Survey Telescope And Rapid Response System (PANSTARRS) comes on line. SSI is monitoring NEO discoveries and expects to discover several suitable asteroids in orbits that allow economic use in the coming years. We still require a much deeper understanding of the physical structure and mineral composition of the twenty odd spectral types of asteroids known to plan materials extraction. SSI has a workshop planned to design asteroid probes to get that knowledge. Such a probe could provide ground truth for multiple spectral types of asteroid relatively cheaply.
Professor Dyson is analyzing the use of mass drivers to provide the thrust for a gravity tractor. The gravity tractor is a clever way to avoid the very time consuming and energetically costly operation of de-spinning an asteroid. SSI studied a mass driver system to transport asteroidal material in the past, however, the gravity tractor idea appears to provide a method to radically reduce costs compared to the earlier ideas.
SSI has identified several areas where broad public education is greatly needed. The potential for the use of space resources to solve mankind’s problems cannot be realized unless we can attract the needed human talent and political support for our efforts. First and foremost is the potential for radical cost reduction in space transportation using combustion rockets. NASA has given up on the development of low cost space transportation. Efforts to achieve it are now almost solely private.It is important that SSI let people know both that low cost space access is possible and why it is important. The second is the potential of various approaches to solar power from space. With oil at ninety dollars per barrel, politicians are looking for energy alternatives. Another is the advantage of space resources to economical space development; closely related, in terms of the technology needed to mitigate, is the threat of asteroid impact. The last is the potential of free space colonies.
SSI’s general public education goal for the next year is to create a web based resource treating those subjects. Thanks to the efforts of David Brandt-Erichsen, past conference proceedings on SSI’s website have been expanded to include abstracts of most of the papers. A follow on goal is to put selected papers deemed especially valuable on the web, free and complete. In the online virtual 3D world Second Life, Senior Advisor Robin Snelson is conducting a pilot research and outreach project on behalf of SSI.
SSI has four new Senior Advisors.
Dr. Klaus Heiss, who will be chairing the economics section at the 2008 Space Manufacturing and Space Settlement Conference, did the economic analysis that lead Congress to authorize the space shuttle program. Unfortunately, his good advice was ignored when selecting high level requirements for the system. Klaus has supported SSI’s space industrialization and space settlement program since the 1970’s.
Dr. Joe Carroll also joined the advisory board. Joe brings enormous energy and depth of experience to all aspects of space engineering. Joe designed and flew the first operational tether in space and was involved in the effort to save the Mir space station using an electrodynamic tether. Joe is known for highly innovative engineering and will be a valuable addition to the SSI family.
John Mankins, who lead the NASA Fresh Look Study of satellite solar power and the NASA space tourism study, joined the Senior Advisory Board in April. John has been leading efforts to revitalize power satellite development.
Dr. Niklas Jarvstrat, Professor of metallurgy and technology of UniWest in Trollhatten, Sweden and leader of the European Moon settlement team also joined the Advisory Board. He is chairing the Space Manufacturing Session at the conference.

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