Long cables to power "ioncraft" to orbit?

[exoscientist]

Posted to sci.astro:<br /><br />Newsgroups: sci.astro, sci.space.policy, sci.physics, sci.electronics.design, sci.electronics.misc <br />From: "Robert Clark" <rgregorycl...@yahoo.com /> <br />Date: 17 May 2005 12:53:31 -0700 <br />Local: Tues,May 17 2005 3:53 pm <br />Subject: Long cables to power "ioncraft" to orbit? <br /><br /> The ioncraft is a method proposed for decades for aircraft and <br />spacecraft propulsion: <br /><br /><br />Ioncraft. <br />http://www.markwilson.com/ionc­raft/ioncraft.html <br /><br /><br /> It works by ionizing the air by electrical charge thereby creating an <br />air flow between the electrodes, generating thrust. There are several <br />examples of these, called "lifters", made by amateurs: <br /><br /><br />The Lifters Experiments home page by Jean-Louis Naudin. <br />http://jnaudin.free.fr/lifters­/main.htm <br /><br /><br /> The problem with them is their power supplies are much heavy than the <br />weight they can lift. But why not leave the power supply on the ground <br />and connect it to the craft by long power cables? <br /><br /><br /> There are carbon fibers that could support their own weight up to <br />hundreds of kilometer of altitude: <br /><br /><br />Carbon fiber (Dani Eder) <br />http://yarchive.net/space/exot­­ic/carbon_fiber.html <br /><br /><br /> And power transmission lines carry electrical power up to 250km away <br />at up to 600 megawatts of power: <br /><br /><br />Baltic-Cable. <br />http://www.answers.com/topic/b­altic-cable?method=5 <br /><br /><br /> This page calculates you can lift 3.91 grams using 7.681 watts of <br />power or about a ratio of 1 to 2: <br /><br /><br />Lifter Theory. <br />http://jnaudin.free.fr/ht</safety_wrapper <div class="Discussion_UserSignature"> </div>

 

[henryhallam]

Unfortunately the lifters do not work outside the atmosphere. I actually tried a small one a few months back, it was quite neat and great to play with if very fiddly to make, but it couldn't lift its own weight in my vacuum chamber when brought down below about half an atmosphere and wouldn't even deflect a lightweight wooden lever horizontally below 150 Torr (for comparison, pressure at airliner altitudes is around 80 Torr).<br /><br />Even just to lift its own weight at sea level is quite a challenge for a lifter. I think expecting them to lift a sizeable payload, long heavy wires and not only to lift all this weight but actually to give it a good acceleration, is asking too much - and the lack of air just makes it completely impossible! If you try to stay down in the denser atmosphere then you run into the same problem as with ramp launches and air launches: You can't give the spacecraft very much velocity or it will simply burn up.<br /><br />I would suggest that it would be better to use beamed microwave power with "rectennas" rather than long wires. I think the energy losses would be only slightly greater (and that doesn't matter much when you can just up the transmitter power). This was successfully demonstrated in the '60s by William Brown with a microwave-powered helicopter! It only hovered at a height of 60ft or so but since then other schemes have beamed power over several kilometers, albeit to stationary receivers.

 

[vogon13]

When working at Sundstrand ATG, I proposed VLEC as an alternative technology to the companies premier product, the Constant Speed Drive aircraft electrical generator.<br /><br />VLEC stands for Very Long Extension Cord.<br /><br />Humorless bunch of twits they were.<br /><br /><img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[exoscientist]

Take a look at the numbers for the power requirements for lifting a payload at the links I cited, Henry. Obviously, the power you would get from the small, portable electrical generators used in these homebuilt lifters would only lift grams to fractions of a gram. I'm suggesting using generators millions of times more powerful.<br /> You're right about the lifters only working in the atmosphere. You could have them operate at a higher acceleration than normally used for rockets to get them to sufficient velocity for orbit quickly. <br /> You're idea about lasers is one that has been suggested often. The problem is getting lasers that have that power output. In contrast there do exist electrical generators (power stations really) that operate at the megawatt and gigawatt scale.<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[henryhallam]

Thanks, I managed to get the links to work now by removing the hyphens that appeared in the URLs (perhaps the fault of my browser). The page by Barsoukov is very informative but Naudin's is talking about things like<br /><i><br />The Possibility of Strong Coupling Between Electricity and Gravitation by Takaaki Musha- Infinite Energy Magazine Issue 53 ( Jan-Feb 2004 ) page 61-64<br /></i><br />and as far as I'm concerned such things are just crackpottery, I don't wish to debate them here.<br /><br />The corona theory seems to give a very solid explanation<br />of the thrust generated, and it deserves more work. I would love to see a complete simulation of a lifter using fluid- and electrodynamics but this is certainly far beyond my maths skills at the moment.<br /><br />More power will get you more lift but there is a limit to how much power you can put through a given mass of "engine" before the corona destroys it. Lack of power supply was not an issue with my model, it was difficult to prevent flashovers and even if you could manage that, the current can only get so high before the coronal action itself starts eating away at the plates. Of course proper research and development could improve them enormously but it just seems a pretty big challenge to me.<br /><br />Having seen the necessary fragility of these things to be able to lift their own weight, it just seems very farfetched that you could get up to decent velocities with them without aerodynamics tearing them apart (since they must necessarily be physically large and would present a great surface area to the air).<br /><br />You don't need enormous lasers for a microwave power transmission system. Ordinary magnetrons work fine with a parabolic antenna. (There is an 800W magnetron in every household microwave oven). If you want greater aiming precision over long distances, a maser can be used and these are easier to build than lasers. <br /><br />Admittedly microwave power transmission has not been tried at levels o