Solar-pumped laser power transmission, a way to dramatically decrease launch costs?
in [Physics]
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From: Brad Guth on 6 Mar 2010 20:08 On Mar 6, 4:49 pm, Marvin the Martian <mar...(a)ontomars.org> wrote: > On Sat, 06 Mar 2010 11:43:21 -0800, William Mook wrote: > > Actually, I think Mr. Mook's idea has merit. > > The military has been working on delivery energy to moving rockets up to > the edge of space for about a decade, now. > > For example: > > http://www.youtube.com/watch?v=6w-ql8msl0U > > "Boeings Airborne Laser (ABL) will locate and track missiles in the boost > phase of their flight, then accurately point and fire the high-energy > laser, destroying enemy missiles near their launch areas." > > The technology to do what Mook proposes is slightly different: easier > because you know and control the telemetry of the target and can use a > ground based laser. A bit more difficult because it requires increased > accuracy and a method to convert it to impulse. > > The subject of using lasers to power rockets dates back back to the Post > Apollo NASA days; I have one reference to doing so, in Lewis' book IIRC, > to using this method. Yes, our Mook isn't always wrong, but instead he's just a couple decades too late to save what little is left of our NASA and DARPA. ~ BG
From: Marvin the Martian on 7 Mar 2010 11:53 On Sat, 06 Mar 2010 21:21:37 -0700, Fred J. McCall wrote: > Marvin the Martian <marvin(a)ontomars.org> wrote: > > :On Sat, 06 Mar 2010 11:43:21 -0800, William Mook wrote: : > :Actually, I think Mr. Mook's idea has merit. : > > Of course you do. Can you spell 'sock puppet'? Yeah, I thought you > could. You're an idiot, McCall. Another damaged ego posting drivel to Sci.physics in the hopes of feeling important. NASA has been looking into laser transfer of energy for propulsion since at least 1976. http://hdl.handle.net/2060/19760014427
From: J. Clarke on 7 Mar 2010 12:50 On 3/7/2010 11:53 AM, Marvin the Martian wrote: > On Sat, 06 Mar 2010 21:21:37 -0700, Fred J. McCall wrote: > >> Marvin the Martian<marvin(a)ontomars.org> wrote: >> >> :On Sat, 06 Mar 2010 11:43:21 -0800, William Mook wrote: : >> :Actually, I think Mr. Mook's idea has merit. : >> >> Of course you do. Can you spell 'sock puppet'? Yeah, I thought you >> could. > > You're an idiot, McCall. Another damaged ego posting drivel to > Sci.physics in the hopes of feeling important. > > NASA has been looking into laser transfer of energy for propulsion since > at least 1976. > > http://hdl.handle.net/2060/19760014427 Yep, and it doesn't address the main driver in launch costs. All these schemes aimed at saving gas are worthless until gas is the major cost driver.
From: William Mook on 7 Mar 2010 16:06 On Mar 7, 12:50 pm, "J. Clarke" <jclarke.use...(a)cox.net> wrote: > On 3/7/2010 11:53 AM, Marvin the Martian wrote: > > > > > On Sat, 06 Mar 2010 21:21:37 -0700, Fred J. McCall wrote: > > >> Marvin the Martian<mar...(a)ontomars.org> wrote: > > >> :On Sat, 06 Mar 2010 11:43:21 -0800, William Mook wrote: : > >> :Actually, I think Mr. Mook's idea has merit. : > > >> Of course you do. Can you spell 'sock puppet'? Yeah, I thought you > >> could. > > > You're an idiot, McCall. Another damaged ego posting drivel to > > Sci.physics in the hopes of feeling important. > > > NASA has been looking into laser transfer of energy for propulsion since > > at least 1976. > > >http://hdl.handle.net/2060/19760014427 > > Yep, and it doesn't address the main driver in launch costs. > > All these schemes aimed at saving gas are worthless until gas is the > major cost driver. Its cost of lift, not gas per se. Cost of lift has to do with the cost of the vehicle. That has to do with empty vehicle weight. So, you can see we're not talking about the cost of propellant, we're talking about the cost of the SYSTEM Consider; Here are the performance of some of the technologies we've either used or discussed in this group. First we list the exhaust speeds attainable, and then we list the thrust to weight of the engine, and then structural fraction of the airframe to carry the propellant Propulsion Technology: Solid Propellant Chemical Rocket: 2.5 km/sec exhaust speed, 100:1 T/ W, 5% structural fraction Hypergolic Propellant Chemical Rocket: 3.2 km/sec exhaust speed, 70:1 T/W, 7% structural fraction Cryogenic Propellant Chemical Rocket: 4.0 km/sec exhaust speed, 70:1 T/ W, 12% structural fraction Nuclear Thermal Rocket (Solid Core): 8.0 km/sec exhaust speed, 10:1 T/ W, 15% structural fraction Nuclear Thermal Rocket (Gas Core): 12.0 km/sec exhaust speed, 7:1 T/W, 15% structural fraction Nuclear Pulse Rocket: 20.0 km/sec exhaust speed, 5:1 T/W, 5% structural fraction Laser Pulse Rocket: 50.0 km/sec exhaust speed, 20:1 T/W, 5% structural fraction So, let's see what impact these figure have on the size and complexity of a vehicle that lofts 60 tonnes into LEO. The Shuttle masses 1,400 tonnes at lift off and carries 24 tonnes into LEO. So, a system 2.5x more massive would loft 60 tonnes into LEO and mass 3,500 tonnes - which corresponds with a 2.5 stage Cryogenic system described below (external tank is half stage). The Proton UR500 masses 540 tonnes at lift off, and lofts 12 tonnes into LEO. So, a system 5x more massive would weigh 2,700 tonnes at lift off and loft 60 tonnes into LEO - which corresponds with a 3 stage hypergolic system described below. Reference Vehicle: Payload: 60 tonnes, Ideal Delta Vee: 9.2 km/sec So, we construct the following table - Empty Weight Sizes the cost of the vehicle, Take off Weight sizes the cost of the launch center. Technology Propel Struct Stage Pay Vehicle Take Off Weight Empty Weight Solid 4 stage 0.601 0.060 0.338519 0.013132 4,568.98 274.14 3 stage 0.707 0.060 0.233269 0.012693 4,726.97 283.62 2 stage 0.841 0.060 0.098817 0.000965 62,179.99 3,730.80 1 stage 0.975 0.060 NOT POSSIBLE Hypergolic 4 stage 0.513 0.084 0.403075 0.065488 916.20 77.22 3 stage 0.616 0.084 0.299246 0.026797 2,239.07 188.72 2 stage 0.762 0.084 0.153235 0.003598 16,675.41 1,405.50 1 stage 0.944 0.084 NOT POSSIBLE Cryogenic 4 stage 0.437 0.134 0.428419 0.078633 763.04 102.46 3 stage 0.535 0.134 0.330273 0.036026 1,665.45 223.65 2 stage 0.683 0.134 0.182351 0.006064 9,895.24 1,328.79 1 stage 0.900 0.134 NOT POSSIBLE Nuclear Thermal (solid core) 4 stage 0.250 0.250 0.500137 0.125102 479.61 119.90 3 stage 0.318 0.250 0.431586 0.080390 746.36 186.59 2 stage 0.437 0.250 0.312705 0.030578 1,962.22 490.55 1 stage 0.683 0.250 0.066637 0.000296 202,772.68 50,693.17 Nuclear Thermal (gas core) 4 stage 0.174 0.293 0.532725 0.151185 396.86 116.22 3 stage 0.226 0.293 0.481629 0.111722 537.05 157.28 2 stage 0.318 0.293 0.388729 0.058741 1,021.44 299.14 1 stage 0.535 0.293 0.171702 0.005062 11,852.94 3,471.22 Nuclear Pulse 4 stage 0.109 0.250 0.641366 0.263826 227.42 56.86 3 stage 0.142 0.250 0.607844 0.224582 267.16 66.79 2 stage 0.205 0.250 0.544534 0.161463 371.60 92.90 1 stage 0.369 0.250 0.381284 0.055430 1,082.45 270.61 Laser Pulse 4 stage 0.045 0.100 0.855042 0.625118 95.98 9.60 3 stage 0.059 0.100 0.840510 0.593784 101.05 10.10 2 stage 0.088 0.100 0.812105 0.535595 112.02 11.20 1 stage 0.168 0.100 0.731936 0.392120 153.01 15.30 The laser pulse system has an empty vehicle mass 10 to 16 tonnes versus a 4 stage hypergolic system massing 78 tonnes empty. A four stage hypergolic system is the lowest cost existing technology, which is reflected in the launch costs of the Chinese and Russian systems. A three stage cryogenic system is 3x more expensive - which again is reflected in the experience of the USA, Europe and Japan. A laser system once developed will be 1/20th the cost of a Cryogenic system and 1/7th the cost of a Hypergolic system - assuming single use throw- away. A reusable system, reused 100x will be 1/700th the cost of the lowest cost system available today. You can see we're not talking about the cost of propellant, we're talking about the cost of the SYSTEM
From: William Mook on 7 Mar 2010 16:06
On Mar 7, 2:13 pm, Fred J. McCall <fjmcc...(a)gmail.com> wrote: > Marvin the Martian <mar...(a)ontomars.org> wrote: > > :On Sat, 06 Mar 2010 21:21:37 -0700, Fred J. McCall wrote: > : > :> Marvin the Martian <mar...(a)ontomars.org> wrote: > :> > :> :On Sat, 06 Mar 2010 11:43:21 -0800, William Mook wrote: : > :> :Actually, I think Mr. Mook's idea has merit. : > :> > :> Of course you do. Can you spell 'sock puppet'? Yeah, I thought you > :> could. > : > :You're an idiot, McCall. Another damaged ego posting drivel to > :Sci.physics in the hopes of feeling important. > : > > Coming from a nymskull sock puppet, that's really quite funny. > > : > :NASA has been looking into laser transfer of energy for propulsion since > :at least 1976. > : > :http://hdl.handle.net/2060/19760014427 > : > > Yes, I know they have, sock puppet. And they're still not even > considering building such a vehicle. That ought to tell you > something, if only you were sane. > > We now return you to your regularly scheduled Mookery of reality. > > -- > "Ordinarily he is insane. But he has lucid moments when he is > only stupid." > -- Heinrich Heine Marvin, you can't win! lol. |