Check this out, Light powered propulsion is real!!

[rrl2]

Listen... In reply to everyone that said the lightcraft even needed to stay in orbit.<br /><br />Why does it even need to! I'm talking about an easy way to launch many satelites, no some form of space travel. The craft would only need to remain in space for a short amount of time to release the satelite before droppin back down to Earth, and did in any body even read the first post use of stam propulsion!<br /><br />STAGE ONE:<br />Now if the laser could stay on track it could power the craft into the upper reaches of the atmosphere. next a small ship with water as its fuel carrying a satelite will begin to launch.<br /><br />STAGE TWO:<br />The whole time the laser would be pointing at the mirrored surface the water will be reach superheating. There have been books when talking about the travel of the future have said that steam-powered rockets will be ideal for planet exploration.( a laser would point at the capsule yada yada, the water becomes superheated and the molecules get jumpy yada yada, the craft blast away at what they estimate could be mach 20). Now I just want o get the satelite into orbit. When the steam-powered rocket takes off it would surely be able t achieve orbit.<br /><br />STAGE THREE:<br />The water rocket releases the satellite into orbit( Oh! by the way all of this is remote operated from earth).<br /><br />STAGE FOUR: the water heated craft could blow up in the atmospere for all I care, but the light craft parachutes safely back to earth to be reused.<br /><br /><br />mlorrey If a couple of hillbillies made the first nuclear bomb in Oak Ridge, Tennessee. Then I'm sure their be able to position a laser.<br /><br />Any questions?

 

[telfrow]

<font color="yellow">If a couple of hillbillies made the first nuclear bomb in Oak Ridge, Tennessee....</font><br /><br /><img src="/images/icons/rolleyes.gif" /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[tomnackid]

I think I'm actually speechless after reading that post RRL2!!! What the....???<br /><br />Anyway...<br /><br />Here is a link to a PDF of a 2004 presentation about Kare's most recent version of the laser launch system. It uses a vehicle with a heat exchanger and solid state diode lasers (off the shelf technology!) I guess he got frustrated with the slow pace of development of large pulsed lasers and developed the heat exchanger system instead. The beams don't need to be phase arrayed, as long as enough beams converge on the heat exchanger it will work. Cool idea. Anyway there are lots schematics that make the concepts clear (Although as a professional scientific illustrator I think some of his artwork could use a little sprucing up! <img src="/images/icons/wink.gif" /> )<br /><br />www.niac.usra.edu/files/library/meetings/fellows/mar04/897Kare.pdf

 

[tap_sa]

<font color="yellow">"I think I'm actually speechless after reading that post RRL2!!! What the....??? "</font><br /><br />Alas, a troll keeps trolling and the mods abide.

 

[mlorrey]

mcbethcg, <br />Do you understand what a major fraction of orbital velocity is needed to circularize highly eccentric orbits?

 

[baktothemoon]

Here's something that no one has mentioned so far: use the light craft as a first stage that would lift the vehicle up to an acceptable altitude where a rocket engine could then take over. The first stage would just be the bottom half of the craft in the image. The laser would be positioned on the pad and would lift the craft off the ground until the rocket starts to head downrange. At that point the rocket engine would ignite and propel the craft all the way to orbit. This would solve both problems: since the lightcraft stage would operate as a first stage there would be enough oxygen for it to use, and since the first stage travels relatively straight up you wouldn't need to worry about the angle of the beam.<br /><br /><br />Now I will talk totally experimental. (you have been warned, no trolling accusations)<br /><br />How about the laser be placed inside the engine with a mirror at the bottom of the engine that would reflect the laser beam into the ring of the light craft. This way the laser could always be pointed at the proper angle to propel the craft. Also, you could add a turbine from a jet engine into the lightcraft stage that would force air into the ring to increase the pressure of the air inside the ring so that you would achieve greater thrust. This would yield a much more powerful and practical lightcraft since with the laser onboard you would have no aiming, angle, or tracking problems. Also, the thrust would be much greater. <br /><br />"Ask not what your country can do for you, ask what you can do for your country." John F. Kennedy

 

[annodomini2]

<blockquote><font class="small">In reply to:</font><hr /><p>Here's something that no one has mentioned so far: use the light craft as a first stage that would lift the vehicle up to an acceptable altitude where a rocket engine could then take over. The first stage would just be the bottom half of the craft in the image. The laser would be positioned on the pad and would lift the craft off the ground until the rocket starts to head downrange. At that point the rocket engine would ignite and propel the craft all the way to orbit. This would solve both problems: since the lightcraft stage would operate as a first stage there would be enough oxygen for it to use, and since the first stage travels relatively straight up you wouldn't need to worry about the angle of the beam. <p><hr /></p></p></blockquote><br /><br />I believe this is the intention for this technology.<br /><br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Now I will talk totally experimental. (you have been warned, no trolling accusations) <br /><br />How about the laser be placed inside the engine with a mirror at the bottom of the engine that would reflect the laser beam into the ring of the light craft. This way the laser could always be pointed at the proper angle to propel the craft. Also, you could add a turbine from a jet engine into the lightcraft stage that would force air into the ring to increase the pressure of the air inside the ring so that you would achieve greater thrust. This would yield a much more powerful and practical lightcraft since with the laser onboard you would have no aiming, angle, or tracking problems. Also, the thrust would be much greater. <p><hr /></p></p></blockquote><br /><br />Interesting idea, though I doubt it would be beneficial in a turbine as i would guess (I am only guessing), that you may risk stalling the turbine. (increasing the pressure behind the blades).<br /><br />However, for a concept using the same idea on a scramjet, possibly increasing the flow through the engine <div class="Discussion_UserSignature"> </div>

 

[why06]

you probably want to reverse your steps it would take an enourmous amout of power to bost the ship into orbit, use the rocket for this. the laser can blast you away from earth<br /><blockquote><font class="small">In reply to:</font><hr /><p> How about the laser be placed inside the engine with a mirror at the bottom of the engine that would reflect the laser beam into the ring of the light craft. This way the laser could always be pointed at the proper angle to propel the craft. Also, you could add a turbine from a jet engine into the lightcraft stage that would force air into the ring to increase the pressure of the air inside the ring so that you would achieve greater thrust. This would yield a much more powerful and practical lightcraft since with the laser onboard you would have no aiming, angle, or tracking problems. Also, the thrust would be much greater. <p><hr /></p></p></blockquote><br /><br />I'm sorry but the main reasons no one has done tis is the enourmous amount of power you would need to keep onboard. <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>

 

[annodomini2]

<blockquote><font class="small">In reply to:</font><hr /><p>you probably want to reverse your steps it would take an enourmous amout of power to bost the ship into orbit, use the rocket for this. the laser can blast you away from earth<br /><br /> In reply to:<br /><br /> How about the laser be placed inside the engine with a mirror at the bottom of the engine that would reflect the laser beam into the ring of the light craft. This way the laser could always be pointed at the proper angle to propel the craft. Also, you could add a turbine from a jet engine into the lightcraft stage that would force air into the ring to increase the pressure of the air inside the ring so that you would achieve greater thrust. This would yield a much more powerful and practical lightcraft since with the laser onboard you would have no aiming, angle, or tracking problems. Also, the thrust would be much greater.<br /><br /><br /><br />I'm sorry but the main reasons no one has done tis is the enourmous amount of power you would need to keep onboard.<p><hr /></p></p></blockquote><br /><br />Given there is no air in space you would have to add fuel, increasing the mass of the ship. Possibly removing any benefit.<br /><br />The benefit of using something like this in the atmosphere is the fuel is coming from outside the craft.<br /><br />Yes you would need a good lightweight power source, so you're definitely looking at nuclear.<br /><br />But the main reason its not currently in use is that the materials currently available don't provide enough longevity. <br /><br />I've seen a tv program covering this guys research and the main problem is the reflector ring burning out under the intense heat generated. <div class="Discussion_UserSignature"> </div>

 

[qso1]

They were being tested several years back. I thought it a promising concept but back then I wondered what they planned to do once an orbital design would have had to go into orbit. The craft at some point has to angle itself to achieve a proper orbital insertion. The laser would at the very least, have to be in some kind of tiltable mount but would be inneffective once the craft itself went below the horizon of the laser beam.<br /><br />Adding chemical rocket stages seemed to sort of defeat the purpose of LLC technology but there seemed to be no other way around the problem of getting to orbit.<br /><br />I have not seen any recent data on it and recall that the power required to pump a laser for a manned system was enormous. Still, it seemd promising but probably encountered the cost barrier.<br /><br />http://www.lightcrafttechnologies.com/news.html<br /><br />Note the latest news was late 2000 in the link provided.<br /><br />RRL2:<br />mlorrey If a couple of hillbillies made the first nuclear bomb in Oak Ridge, Tennessee. Then I'm sure their be able to position a laser.<br /><br />Me:<br />Almost forgot, it wasn't a couple of hillbillies that developed the bomb. Not to mention it appears hillbillies, rednecks, trailer trash are the only groups left that someone can make fun of without fear of political correctness backlash. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[rocketman5000]

an asymetric craft design could help to counter act the skewed beam. providing a moment due to differences in its COM compared to the center of pressure

 

[nexium]

Average (RMS?) multimegawatt laser arrays are presently operational. They can propel somewhat larger and faster models. A gigawatt of lasers will be optimumly positioned for space elevators by 2020 if the space elevators stay on schedual. The positioning should also be suitable for "light craft" www.liftport.com has a great forum. My guess is; this is a costly way to get tiny payloads half way to orbit, but we won't know for sure unless we try. Present lasers are too heavy and power hungry to instal in the craft. Neil

 

[qso1]

Sounds like at least one of the reasons I haven't seen much activity on LLC recently.<br /><br />I did some research into LLC 5 or 6 years ago and somewhere I found the following data:<br /><br />A 1 megawatt laser is required to lift a vehicle with a 2.2 pound payload presumably to LEO. 1 Gw is required to lift 1 ton to LEO and 100 Gw to lift 100 tons to LEO. <br /><br />Data I ended up not using and have since lost the link but its not what I'd call a technical showstopper (Except where payloads over perhaps 20 tons are concerned) but maybe, as you point out, a cost one.<br /><br />I'd say currently, the only way to be cost effective is to come up with a way where even if chemical upper stages are used, that the laser is used to the maximum extent possible. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[spacelifejunkie]

Here are a couple of websites that have been neglected for a number of years that seem to be the latest information on lightcraft. Also, check out the TheSpaceShow.com for interviews with Leik Myrabo. Myrabo's latest book is currently for sale (still waiting on my copy) and should provide the latest and greatest. <br />The end goal of this project is not necessarily laser but microwave powered craft. It still seems way out there but fascinating nonetheless. It will take a lot of power.<br /><br />SLJ<br /><br /><br /><br />http://www.lightcrafttechnologies.com/media.html<br />http://www.eng.rpi.edu/mane/lightcraft/Curriculum/TAVD/