[Vo]: Re: Rocket Ideas
A rocket supplied with energy beamed from a space power transmitter should get as much momentum reaction from its fuel mass as possible so relativistic beams are suitable here if the accelerator is very light. The power transmitter can send out relativistic particle beams rather than light. It may work but if power is to be beamed from a power station then light seems better to me. Install a powerful laser source on the Moon and point it to the ship's solar sail. Same thing on Mars for the return trip. Or maybe an array of station-based solar reflectors pointed at the sail, the good old Archimedes way, would work too. This kind of stuff has probably been thoroughly researched already. Michel - Original Message - From: [EMAIL PROTECTED] To: vortex-l@eskimo.com Sent: Monday, January 08, 2007 5:43 AM Subject: [Vo]: Rocket Ideas A fusion power source converts only a small percentage of mass into energy so there may not be enough energy to accelerate all the fusion reaction products to relativistic speeds anyway. This suggests a plasma rocket engine which would have good thrust with adequate Isp, specific impulse. Extremely hot exhaust would be ejected through a magnetic nozzle. An antimatter fueled rocket would contain a lot of energy. The antimater needs to be synthesized from other energy sources. A lightweight particle accelerator producing relativistic thrust from a small amount of mass would be appropriate here. A rocket supplied with energy beamed from a space power transmitter should get as much momentum reaction from its fuel mass as possible so relativistic beams are suitable here if the accelerator is very light. The power transmitter can send out relativistic particle beams rather than light. The momentum of the matter beam may not be captured well by a thin sail, radiation may be generated, and the sail may disintegrate rapidly. A sail with aligned pores open to the impinging beam may work well. Maybe the spacecraft could use part of the drive out beam to synthesize antimatter so antimatter would be created far away going farther. Diode arrays would convert the ambient heat of an atmosphere into electrical power when leaving a planet or large moon with an atmosphere. An onboard energy supply is needed for continued acceleration between the high atmosphere and low space. Diode arrays would also convert the reentry heat of a rocket descending through an atmosphere into retrorocket power. Diode arrays may achieve suitcase gigawatt performance levels. They would convert heat into electricity for spacecraft propulsion and other needs. Diode arrays can recycle the losses of fusion reactors so the nuclear energy produced will appear as net output. Aloha, Charlie
Re: [Vo]: removing junk [Re moving satellites]
Good point, but the process may take longer than desirable. Michel - Original Message - From: Robin van Spaandonk [EMAIL PROTECTED] To: vortex-l@eskimo.com Sent: Monday, January 08, 2007 7:12 AM Subject: Re: [Vo]: removing junk [Re moving satellites] In reply to [EMAIL PROTECTED]'s message of Mon, 08 Jan 2007 05:41:53 +: Hi, [snip] I want to clear out space junk. Its a lot of dangerous objects dispersed in a huge volume. Earthpeople may rise to the responsibility of keeping space safe. Aloha, Charlie Most of the space junk we create is in Earth orbit, and it's orbit eventually decays with time, resulting in it burning up in the atmosphere. Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition provides the motivation, Cooperation provides the means.
[Vo]: Re: Re: Rocket Ideas
BTW such Moon station based light beams might also be useful to deviate space junk into, and threatening asteroids out of, an earth intersecting orbit. Not to mention earth uses such as night lighting of disaster areas. Michel - Original Message - From: Michel Jullian [EMAIL PROTECTED] To: vortex-l@eskimo.com Sent: Monday, January 08, 2007 9:29 AM Subject: [Vo]: Re: Rocket Ideas A rocket supplied with energy beamed from a space power transmitter should get as much momentum reaction from its fuel mass as possible so relativistic beams are suitable here if the accelerator is very light. The power transmitter can send out relativistic particle beams rather than light. It may work but if power is to be beamed from a power station then light seems better to me. Install a powerful laser source on the Moon and point it to the ship's solar sail. Same thing on Mars for the return trip. Or maybe an array of station-based solar reflectors pointed at the sail, the good old Archimedes way, would work too. This kind of stuff has probably been thoroughly researched already. Michel - Original Message - From: [EMAIL PROTECTED] To: vortex-l@eskimo.com Sent: Monday, January 08, 2007 5:43 AM Subject: [Vo]: Rocket Ideas A fusion power source converts only a small percentage of mass into energy so there may not be enough energy to accelerate all the fusion reaction products to relativistic speeds anyway. This suggests a plasma rocket engine which would have good thrust with adequate Isp, specific impulse. Extremely hot exhaust would be ejected through a magnetic nozzle. An antimatter fueled rocket would contain a lot of energy. The antimater needs to be synthesized from other energy sources. A lightweight particle accelerator producing relativistic thrust from a small amount of mass would be appropriate here. A rocket supplied with energy beamed from a space power transmitter should get as much momentum reaction from its fuel mass as possible so relativistic beams are suitable here if the accelerator is very light. The power transmitter can send out relativistic particle beams rather than light. The momentum of the matter beam may not be captured well by a thin sail, radiation may be generated, and the sail may disintegrate rapidly. A sail with aligned pores open to the impinging beam may work well. Maybe the spacecraft could use part of the drive out beam to synthesize antimatter so antimatter would be created far away going farther. Diode arrays would convert the ambient heat of an atmosphere into electrical power when leaving a planet or large moon with an atmosphere. An onboard energy supply is needed for continued acceleration between the high atmosphere and low space. Diode arrays would also convert the reentry heat of a rocket descending through an atmosphere into retrorocket power. Diode arrays may achieve suitcase gigawatt performance levels. They would convert heat into electricity for spacecraft propulsion and other needs. Diode arrays can recycle the losses of fusion reactors so the nuclear energy produced will appear as net output. Aloha, Charlie
Re: [Vo]: Optics question
A good idea but then it's a different beast altogether, it's a classical scanning laser display, and you must have only one steerable (or rotating multifaceted, one facet per line) mirror per laser source, not an array of micromirrors. The problem with scanning laser displays is that for a given display luminosity laser light is much more expensive than the light bulbs used in DLP displays. And less energy-efficient too I would think, even when taking into account the DLP's light dumping losses in question. Michel - Original Message - From: Robin van Spaandonk [EMAIL PROTECTED] To: vortex-l@eskimo.com Sent: Monday, January 08, 2007 3:20 AM Subject: Re: [Vo]: Optics question In reply to Hoyt A. Stearns Jr.'s message of Sat, 6 Jan 2007 17:41:40 -0700: Hi, [snip] In a digital light processing (DLP) display, a light source (soon to be a tri color laser) projects on an array of movable mirrors. The light for the dark parts of the image are sent to a beam dump. That seems wasteful. Is it possible to collect that light and re-introduce it into the primary source? Instead of using the mirrors to direct the beam to a beam dump, simply turn the laser off for a fraction of a second. This will require a change in the logic and electronics, but is much more efficient (instead of recovering the energy, it is simply not used in the first place). It also means that the mirrors can continue to scan the line, maintaining momentum. Then the mirrors need not be as easy to maneuver, which is technically simpler and cheaper to implement, as well as resulting in a more robust design that produces a better quality image. Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition provides the motivation, Cooperation provides the means.
[Vo]: On AlGoil and Corporate-Energy-Responsibility
Even Oil Drillers are getting into the ecology act ... http://www.petrosuninc.com/alternative-energy.html To paraphrase their corporate motivation for doing this (aside from potential profits down-the-road): Crops such as soybeans and sunflowers produce oil that can be used to make biodiesel, but no food-crop may be sustainable in the long term; and moreover any of them will deprive the world-at-large of food resources. The solution - no pun intended - is to be found in microalgae - now being called either Oilgae or Algoil (the later in homage to AlGore - the most responsible politician to come along (for alternative energy concerns) in decades. Where it nor for the 'chad' debacle in the Sunshine State (a prime area for growing Algoil) he might have been able to do something more substantive and political - instead of cinematic (although one cannot under-estimate how fast power corrupts - even corrupting well-meaning individuals - once they get inside the DC beltway). Independent studies have demonstrated that algae are capable of producing 30 times more oil per acre than corn or soybean crops; and can be harvest mechanically (robotically?) all year long. Biodiesel produced from algae contains no sulfur, is non-toxic, has high energy-density like petro-diesel but is even biodegradable (unlike petro-diesel). This IS solar energy conversion, done elegantly, since whereas solar panels are expensive and are around 20% efficient in converting solar to electricity (which is non easily stored), Algoil is up to 60% efficient (triple!) in converting solar into a storable transportation fuel. Plus algae are carbon-neutral, whereas solar panels use so much carbon-equivalent in their manufacture that it takes 5 years to just break even in an ecological sense. Plus, wind farms can be sited over algae ponds for an odd kind of synergy (such as aerating ponds to get more CO2 into the water), and saline ponds, particularly in desert areas work just as well or better than fresh water - so there is no overuse of drinkable water. It is win-win for Algoil. Too bad the same cannot be said for AlGore. And one of the biggest infrastructure advantages of biodiesel compared to other alternative transportation fuels like hydrogen or ethanol, is that it can be used in existing diesel engines, which relieves manufacturers of having to make costly engine modifications. Biodiesel can also be mixed, at any ratio, with conventional petroleum diesel or ethanol/methanol. As a result, the alternative fuel can be used in the current distribution infrastructure, replacing petroleum diesel as a diesel blend, with minimal integration costs. Hey Vo's - Let's have a round of symbolic-applause for Algoil - at least by investing in responsible companies like PetroSun Jones
[Vo]: Mini-Mag Orion rocket concept
Not CF, but impressive: http://www.andrews-space.com/images/videos/PAPERS/Pub-MMOJPLTalk.pdf - Jed
Re: [Vo]: Optics question
There is a misunderstanding of the nature of DLP technology. The active element is an array of tiny mirrors created by silicon machining techniques, one for each pixel. Each mirror can be tilted by a small angle under control from a TV signal. That tilt determines wihether the light falling on it goes to a location on the screen or to a dump. The average intensityof each pixel is determined by the fraction of time the mirror illuminates the screen. The individual mirrors do not scan, they only switch light to or away from one location on the screen. The optics, once fixed, are quite robust. The only variable is the lamp. which has finite life and must be changed. Mike Carrell --- In reply to Hoyt A. Stearns Jr.'s message of Sat, 6 Jan 2007 17:41:40 -0700: Hi, [snip] In a digital light processing (DLP) display, a light source (soon to be a tri color laser) projects on an array of movable mirrors. The light for the dark parts of the image are sent to a beam dump. That seems wasteful. Is it possible to collect that light and re-introduce it into the primary source? Instead of using the mirrors to direct the beam to a beam dump, simply turn the laser off for a fraction of a second. This will require a change in the logic and electronics, but is much more efficient (instead of recovering the energy, it is simply not used in the first place). It also means that the mirrors can continue to scan the line, maintaining momentum. Then the mirrors need not be as easy to maneuver, which is technically simpler and cheaper to implement, as well as resulting in a more robust design that produces a better quality image. Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition provides the motivation, Cooperation provides the means. This Email has been scanned for all viruses by Medford Leas I.T. Department.
Re: [Vo]: Mini-Mag Orion rocket concept
Robin van Spaandonk wrote: I have two questions: 1) How are they going to control direction of flight, and prevent off axis thrust from spinning the craft? I always wondered how that would work with the original Orion concept, but Dyson and others said they had that under control. With this gadget it should be easier because the explosive charges held in place with tape before it is exploded, so it should hit the center of the target. With the original Orian, they toss the bomb out and have it go off at just the right moment, which seems highly problematic, to say the least. At least with this thing they hold it in place. 2) Where is the Cf coming from to power it? (I presume they mean Cf, and not Cu as indicated on page 12.) Dunno. This is kind of like all those rockets people want to make with helium-3. Personally, I think anyone would have to be insane to sit that close to a nuclear explosion, let alone a whole series of them. The simulations and tests show that this would not be a problem, believe it or not. However, I would not want to be the first to ride in one. I think these gadgets would be better for deep space applications than Earth to orbit. First, because we do not want to pollution on earth. Second, because lift off from Earth, if the explosion misfires, or something goes wrong with the bomb ejector machine designed by the people who make Coca-Cola machines (really!) for the original Orion, you are toast. Whereas if something goes wrong in deep space, you coast along for a while, fix the problem and then restart. I wonder if you could have a sort of hybrid or half-hot fusion machine, where you position a standard inertial confinement pellet with strips of plastic, and then zap it with laser beams driven by CF. as far as I know, this kind of hot fusion has not produced more energy out than in, but if it produced a small explosion with very rapid ejecta it might be a way to convert CF electricity into thrust. When I discussed lasers previously, I had in mind that ordinary water would be heated to about 1000°C with ordinary CF, and then heated to around 10,000°C with lasers to increase momentum per unit mass of propellant (specific impulse, or ISP -- I believe it is called). Maybe you could even use the same CF engine for high thrust takeoff and low thrust, high ISP, deep space operation. Imagine a CF version of the Phoebus 2, with 5,000 megawatts output, 250,000 lb thrust. On takeoff it consumes ~200 kg of water per second, probably along with booster engines that stay behind on earth. An auxiliary laser system adds another 100 MW to the output steam, raising the temperature somewhat. Once it escapes earth's gravity the main engine throttles way down, and only 0.2 kg per second passes through it (10 kg per minute; 14 tons per day), but the lasers raise the temperature to 10,000°C which gives it a lot more umph. The generator and laser gadgets together might weight as much as the Phoebus 2, producing far less thrust overall, of course. I realize that other approaches are theoretically far more efficient, but I do not think any of them are practical -- or close to practical. Whereas high temperature CF might be close to reality, and generators and lasers exist. Perhaps microwaves or some other method could be used to heat the steam far beyond the melting point of the CF device. Whatever device is lightest would be best. - Jed
[Vo]: unsubscribe
-Original Message- From: Mike Carrell [mailto:[EMAIL PROTECTED] Sent: Monday, January 08, 2007 5:02 PM To: vortex-l@eskimo.com Subject: Re: [Vo]: Optics question There is a misunderstanding of the nature of DLP technology. The active element is an array of tiny mirrors created by silicon machining techniques, one for each pixel. Each mirror can be tilted by a small angle under control from a TV signal. That tilt determines wihether the light falling on it goes to a location on the screen or to a dump. The average intensityof each pixel is determined by the fraction of time the mirror illuminates the screen. The individual mirrors do not scan, they only switch light to or away from one location on the screen. The optics, once fixed, are quite robust. The only variable is the lamp. which has finite life and must be changed. Mike Carrell --- In reply to Hoyt A. Stearns Jr.'s message of Sat, 6 Jan 2007 17:41:40 -0700: Hi, [snip] In a digital light processing (DLP) display, a light source (soon to be a tri color laser) projects on an array of movable mirrors. The light for the dark parts of the image are sent to a beam dump. That seems wasteful. Is it possible to collect that light and re-introduce it into the primary source? Instead of using the mirrors to direct the beam to a beam dump, simply turn the laser off for a fraction of a second. This will require a change in the logic and electronics, but is much more efficient (instead of recovering the energy, it is simply not used in the first place). It also means that the mirrors can continue to scan the line, maintaining momentum. Then the mirrors need not be as easy to maneuver, which is technically simpler and cheaper to implement, as well as resulting in a more robust design that produces a better quality image. Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition provides the motivation, Cooperation provides the means. This Email has been scanned for all viruses by Medford Leas I.T. Department.
Re: [Vo]: Optics question
Mike Carrell wrote: There is a misunderstanding of the nature of DLP technology. The active element is an array of tiny mirrors created by silicon machining techniques, one for each pixel. Each mirror can be tilted by a small angle under control from a TV signal. That tilt determines wihether the light falling on it goes to a location on the screen or to a dump. The average intensityof each pixel is determined by the fraction of time the mirror illuminates the screen. The individual mirrors do not scan, they only switch light to or away from one location on the screen. The optics, once fixed, are quite robust. The only variable is the lamp. which has finite life and must be changed. Exactly right. About 10 years ago, when the practical application of DLP was in its infancy, I was asked to consult about methods of improving light usage in DLP systems. My suggestion, which sounds sophisticated, but is in fact very simple, was as follows: Each mirror facet, instead of being a plane mirror would be etched as a fresnel zone plate, the diffraction equivalent of a lens. At the focus of the zone plates would be a holographic optical element (HOE) that would represent a secondary pixel array much finer than the original mirror zone plate array. The light could then be directed to the proper section of the HOE to illuminate the pixels as needed. Hardly any light would be wasted except for losses due to having an extra element in the system. Naturally, an all black picture would still represent 100% light loss, but on the average, this system would require a much lower power lamp for the same image brightness. This sounds all very well and good, but the digital processing power necessary was not available at consumer prices at the time. As we all know, processor speed and power has increased geometrically in the last decade. I'm still waiting for that call-back. How may Rs in fat chance? M. ___ Join Excite! - http://www.excite.com The most personalized portal on the Web!
Re: [Vo]: Optics question
On 1/8/07, Mike Carrell [EMAIL PROTECTED] wrote: There is a misunderstanding of the nature of DLP technology. The active element is an array of tiny mirrors created by silicon machining techniques, one for each pixel. You forget the spinning light filter for RGB. Truly a rube goldberg technology: http://www.dlp.com/ Terry
