PHASE-CHANGE MICRO-THRUSTERS
To: [EMAIL PROTECTED] From: "J. R. Molloy" [EMAIL PROTECTED] Mailing-List: list [EMAIL PROTECTED]; contact [EMAIL PROTECTED] Delivered-To: mailing list [EMAIL PROTECTED] Date: Tue, 16 Jan 2001 10:03:56 -0800 Reply-To: [EMAIL PROTECTED] Subject: [Htech] MICRO-THRUSTERS PHASE-CHANGE MICRO-THRUSTERS http://sec353.jpl.nasa.gov/apc/Micropropulsion/01.html MEMS (Micro-Electromechanical Systems) based phase change thruster concepts are currently under investigation matching Class I and II microspacecraft requirements. Among the concepts considered are subliming solid micro-thrusters and vaporizing liquid micro-thrusters, currently under development at JPL. Fabrication of both thruster types relies on micro-machining methods similar to those used in the micro-electronics industry in order to obtain nozzle throat sizes small enough to obtain the required low thrust and impulse bit performances. Both thruster types also use non-gaseous propellants in order to reduce leakage problems. Currently, no suitable flight qualifiable microvalve concept exists to reduce leakage rates. In the case of the subliming solid microthruster, a solid propellant (ammonia salts) is sublimated by heating the tank until a suitable tank pressure is reached. Then a microvalve is opened (due to solid propellant storage the leak rate requirements for this valve are not very stringent) and the gaseous phase of the propellant is vented to produce thrust. In the case of the vaporizing liquid thruster, a suitable liquid propellant (e.g. water, ammonia, hydrazine) is fed into a micro-thin film heater assembly that vaporizes the propellant just prior to exiting the nozzle. Both concepts are in the early development stage at JPL. Hardware fabrication has begun and thrust stand tests are expected to be performed in 1997. Many feasibility issues, however, remain with these and other potential micro-thruster concepts. **Article includes excellent graphics** Stay hungry, --J. R. 3M TA3 Useless hypotheses: consciousness, phlogiston, philosophy, vitalism, mind, free will -BEGIN TRANSHUMANTECH SIGNATURE- Post message: [EMAIL PROTECTED] Subscribe:[EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] List owner: [EMAIL PROTECTED] List home:http://www.egroups.com/community/transhumantech/ Alt archive: http://www.planetx.com/majordomo/transhumantech/ Old archive: http://www.planetx.com/transhumantech/threads.html -END TRANSHUMANTECH SIGNATURE- (u are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
Vacuum powered micro-machines
To: [EMAIL PROTECTED] From: "J. R. Molloy" [EMAIL PROTECTED] Mailing-List: list [EMAIL PROTECTED]; contact [EMAIL PROTECTED] Delivered-To: mailing list [EMAIL PROTECTED] Date: Tue, 16 Jan 2001 10:20:27 -0800 Reply-To: [EMAIL PROTECTED] Subject: [Htech] Vacuum powered micro-machines Quantum Fields LLC Quantum Vacuum Forces Project http://www.quantumfields.com/projects.htm Quantum electrodynamics (QED) is probably the best verified theory in physics. It makes some startling predictions about the importance of quantum fluctuations of the electromagnetic field in empty space. It predicts a near infinite vacuum energy density. Quantum fluctuations have been linked to particle mass, to spontaneous emission, to the speed of light, and to the topology of the universe. The presence of surfaces changes the energy density in the vacuum fluctuations. The ability to alter these parameters could be of significant benefit to the Breakthrough Propulsion Physics (BPP) objectives. We will perform a theoretical investigation of the use of surfaces and cavity structures in order to alter vacuum energy. A Micro Electro Mechanical System (MEMS) interferometer structure is planned to measure the index of refraction in a cavity, which will serve as a test of QED predictions. The variations in vacuum energy produced by surfaces can also result in vacuum forces, such as the recently verified Casimir force between two parallel conducting plates. Very few other geometrical structures have been investigated, and our understanding of the role of surfaces in altering vacuum energy and generating vacuum forces rudimentary. For rectangular cavities, forces are predicted on the walls that may be inward, outward or zero depending on the ratios of the sides. Such forces may be of use in operating MEMS devices, including resonant cavities. We propose to model and build a MEMS cavity structure, to verify the QED prediction of repulsive forces, and to study the properties of these cavities and the energy balance in a static and in a vibrating mode. When we have gained a greater understanding of cavities and vibrating structures, a second generation MEMS structure will be designed, modeled, fabricated and tested. We will investigate the possibility of fluctuation driven engines that operate between two regions of different energy density, in a similar manner to which heat engines operate at different temperature. Two types of engines will be considered: one in which one set of surfaces moves relative to another, akin to an electric motor, and a second type in which a working fluid, perhaps consisting of atoms or electrons, passes between the two regions of different vacuum energy. We will develop several candidate structures for fluctuation engines and fabricate the most promising. In all theoretical and experimental work, care will be taken to understand energy balance requirements and conservation laws, and to determine what is possible and what is not. QED computations will be used as the guide. This effort will answer many of the basic questions about the role of vacuum fluctuations, and lay a solid foundation of knowledge about vacuum energy, vacuum stress and how to control them using surfaces and what their limitations are. Researchers will be able to build upon this knowledge to build more complex ideas and structures involving vacuum fluctuations. The program represents a unique collaborative effort involving strong QED theorists, experts in propulsion, gravitation, and other relevant technologies, coupled with highly qualified and experienced developers of MEMS devices. The Principle Investigator, an experienced researcher who is trained in QED and Casimir phenomena, and who has worked for over 15 years in microfabrication technology and experimental measurements, is uniquely qualified to lead this effort. The effort will answer questions about the energy in the vacuum and if and how we might be able to utilize it in the BPP mission. -BEGIN TRANSHUMANTECH SIGNATURE- Post message: [EMAIL PROTECTED] List owner: [EMAIL PROTECTED] List home:http://www.egroups.com/community/transhumantech/ Alt archive: http://www.planetx.com/majordomo/transhumantech/ Old archive: http://www.planetx.com/transhumantech/threads.html -END TRANSHUMANTECH SIGNATURE- == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
New Space Technology Guide Omits Nuclear Power
NEW SPACE TECHNOLOGY GUIDE OMITS NUCLEAR POWER The Department of Defense has published a new "Space Technology Guide" that responds to a legislative requirement "to identify the technologies needed ... to take full advantage of use of space for national security purposes." The Guide covers the familiar gamut of "enabling technologies" for national security space activities from propulsion to communications to materials, and so forth. With one exception. Unlike practically every other survey of military space technologies over the past few decades, the new Guide conspicuously omits any mention of space nuclear power. Space nuclear reactors have long been on the military's wish list because they would offer an exceptionally high power to mass ratio in a compact, survivable form. Just what you need to drive your orbital weapons platform. But for that reason, they have also been a lightning rod for public concern and criticism. In 1988, a proposal for a ban on nuclear reactors in Earth orbit was developed by the Los Angeles-based Committee to Bridge the Gap and advanced as an arms control measure by U.S. and Russian scientists, including the Federation of American Scientists. Other forms of nuclear power for civilian space exploration have also been opposed by anti-nuclear activists. A Pentagon spokesman did not immediately respond to a request for an explanation of the omission of space nuclear power from the latest planning documents. The U.S. launched one 500 Watt space nuclear reactor in 1965. Dozens of reactors were deployed in orbit by the former Soviet Union between 1967 and 1988. The last major U.S. space nuclear reactor development program, known as the SP-100, was canceled nearly a decade ago. The new DoD Space Technology Guide is posted here: http://www.fas.org/spp/military/stg.htm == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
Re: New Space Technology Guide Omits Nuclear Power
Of course, if the "official" guide omits any mention of nuclear powered craft, that could be because they are keeping sensitive military information to themselves. I don't think there were too many corporate memos circling around about the Manhattan project. On Tue, 6 Feb 2001, Larry Klaes wrote: NEW SPACE TECHNOLOGY GUIDE OMITS NUCLEAR POWER The Department of Defense has published a new "Space Technology Guide" that responds to a legislative requirement "to identify the technologies needed ... to take full advantage of use of space for national security purposes." The Guide covers the familiar gamut of "enabling technologies" for national security space activities from propulsion to communications to materials, and so forth. With one exception. Unlike practically every other survey of military space technologies over the past few decades, the new Guide conspicuously omits any mention of space nuclear power. Space nuclear reactors have long been on the military's wish list because they would offer an exceptionally high power to mass ratio in a compact, survivable form. Just what you need to drive your orbital weapons platform. But for that reason, they have also been a lightning rod for public concern and criticism. In 1988, a proposal for a ban on nuclear reactors in Earth orbit was developed by the Los Angeles-based Committee to Bridge the Gap and advanced as an arms control measure by U.S. and Russian scientists, including the Federation of American Scientists. Other forms of nuclear power for civilian space exploration have also been opposed by anti-nuclear activists. A Pentagon spokesman did not immediately respond to a request for an explanation of the omission of space nuclear power from the latest planning documents. The U.S. launched one 500 Watt space nuclear reactor in 1965. Dozens of reactors were deployed in orbit by the former Soviet Union between 1967 and 1988. The last major U.S. space nuclear reactor development program, known as the SP-100, was canceled nearly a decade ago. The new DoD Space Technology Guide is posted here: http://www.fas.org/spp/military/stg.htm == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/ == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
CCNet 9/2001 - 17 January 2001
From: Peiser Benny [EMAIL PROTECTED] To: cambridge-conference [EMAIL PROTECTED] Subject: CCNet, 17 January 2001 Date: Wed, 17 Jan 2001 12:49:04 - CCNet 9/2001 - 17 January 2001 -- "The project also aims to see if scientists can alter the orbit of a comet to protect theEarth from falling matter. The impact would alter the comet's orbit by a "just barely measurable" 62 to 620 miles (100 to 1,000 km), [Mike] A'Hearn said." --The New York Times, 17 January 2001 "My research has been one disaster after another. [...] You need to have one interestingidea every day. Just like James Bond has a license to kill, I had a license to depart from the normal path of a scientist." --Richard A. Muller, 16 January 2001 (1) NASA AIMS TO BLAST COMET TO STUDY SOLAR SYSTEM Oliver Morton [EMAIL PROTECTED] (2) ONE DISASTER AFTER ANOTHER Scientific American, 17 January 2001 (3) LUSTING AFTER A LANDING ON EROS Weired Magazine, 16 January 2001 (4) ICE CHANNELS ON MARS Harvey Leifert[EMAIL PROTECTED] (5) SYNCHRONOUS PLANETARY ORBITS FOUND IN NEW SOLAR SYSTEM UniSci, 16 January 2001 (6) DISASTER DIPLOMACY Ilan Kelman [EMAIL PROTECTED] (7) WHERE DID SOLAR-SYSTEM LIFE BEGIN? Oliver Morton [EMAIL PROTECTED] (8) WHERE DID SOLAR-SYSTEM LIFE BEGIN? Steve Drury [EMAIL PROTECTED] == (1) NASA AIMS TO BLAST COMET TO STUDY SOLAR SYSTEM From Oliver Morton [EMAIL PROTECTED] Benny -- this is the first time I've seen Deep Impact talked of -- albeit in passing -- as having some implications for planetary defence. Maybe I just haven't been paying attention. oliver morton [EMAIL PROTECTED] NASA Aims to Blast Comet to Study Solar System http://www.nytimes.com/2001/01/17/science/science-space-chile-d.html January 17, 2001 By REUTERS SANTIAGO, Chile - NASA scientists aim to blast a comet with a copper projectile to learn about the formation of the solar system as part of a $270 million project funded by NASA, the head of the project said on Tuesday. The project, called Deep Impact and which will cause an explosion capable of destroying a small town, would be the first space mission to probe inside a comet, whose primitive core could reveal clues about evolution of the solar system. "All our studies of comets look only at the surface layer. Our theoretical models tell us the surface has changed, and only the interior has the original composition. So our main goal is to compare the interior with the surface," the project's director, Michael A'Hearn, told reporters. Scientists chose copper, Chile's No. 1 export, because it is less likely to interfere with the materials inside the crater. In January 2004, a rocket would launch from Cape Canaveral, Florida, a spacecraft that would orbit the sun. In July 2005 the spacecraft would separate from a battery-powered, copper projectile that would collide with the comet 24 hours later at a velocity of 6 miles (10 km) per second. It would produce a crater the width of a football field and up to 100 feet (30 meters) deep. The spacecraft would observe the composition of the crater's interior, while telescopes on Earth would monitor the impact. The project also aims to see if scientists can alter the orbit of a comet to protect the Earth from falling matter. The impact would alter the comet's orbit by a "just barely measurable" 62 to 620 miles (100 to 1,000 km), A'Hearn said. The project would blast the Comet Tempel 1, which was discovered in 1867 and is a little less than Earth's distance from the sun, he said. It was chosen because its size, rotation and trajectory favor the project and because the collision would be observable from Earth. In February, NASA will carry out a preliminary design review to see if the project can succeed. Copyright 2000 The New York Times Company == (2) ONE DISASTER AFTER ANOTHER From Scientific American, 17 January 2001 http://www.sciam.com/2001/0201issue/0201profile.html The father of the idea that a sibling of the sun periodically wreaks havoc on Earth finds inspiration in catastrophes BERKELEY, CALIF.--I first meet Richard A. Muller during a record-breaking heat wave. The astrophysicist is on his way to get a refreshment. Bottles of his favorite cold dairy drink--mocha milk--are stacked in a nearby vending machine. Through the clear front, the scientist notices something out of place: a juice can trapped obliquely against the glass. "I'll get either two drinks or none," he predicts playfully, inserting his change and selecting the beverage he thinks is most likely to knock the can free. Muller is unconcerned (or perhaps oblivious) that this selection is vanilla, not the flavor he came for. His purchase grazes the target but fails to knock the bottle down. Gambles like this one typify the life of Richard Muller--although usually the stakes are higher. The restless researcher loves to
Re: New Space Technology Guide Omits Nuclear Power
In a message dated 2/6/2001 11:46:22 AM Alaskan Standard Time, [EMAIL PROTECTED] writes: Of course, if the "official" guide omits any mention of nuclear powered craft, that could be because they are keeping sensitive military information to themselves. I don't think there were too many corporate memos circling around about the Manhattan project. Alternatively, such an 'official guide' is merely popcorn for the public -- looks pretty, but doesn't satisfy. It wouldn't do to mention nuclear power in an official guide that is supposed to drum up public support. Ergo, lots of pretty pictures, and a few unworkable 'space age' ideas. As the fellow above suggests, nuclear powered propulsion units are noteworthy as the exception, and that really says something beyond their substantive value as technology. In the event of a real, pressing need, however, I have no doubt that nuclear power would be developed for space propulsion. From what I've gleaned, however, more than half of a space mission is public relations. -- JHB == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
Martian Ice Puts Arizona Scientist In The Groove
X-Recipient: [EMAIL PROTECTED] Date: Wed, 17 Jan 2001 09:44:26 -0800 (PST) From: [EMAIL PROTECTED] Subject: Martian Ice Puts Arizona Scientist In The Groove Reply-To: [EMAIL PROTECTED] To: undisclosed-recipients:; http://www.spacedaily.com/news/mars-water-science-01b.html Martian Ice Puts Arizona Scientist In The Groove SpaceDaily Flagstaff - Jan. 17, 2001 Some channels visible on the surface of Mars may have been gouged by ice, rather than by catastrophic flooding, as is generally believed. That is the view of Dr. Baerbel K. Lucchitta of the U.S. Geological Survey in Flagstaff, Arizona, who compared the Martian features with strikingly similar ones on the Antarctic sea floor. Her findings are reported in the February 1 issue of Geophysical Research Letters, a publication of the American Geophysical Union. Full story here: http://www.spacedaily.com/news/mars-water-science-01b.html == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
