tag:blogger.com,1999:blog-8150340806781551727.post3754621134306518035..comments2024-03-29T07:43:40.648+00:00Comments on ToughSF: Laser Launch into OrbitMatter Beamhttp://www.blogger.com/profile/16721504049578296529noreply@blogger.comBlogger36125tag:blogger.com,1999:blog-8150340806781551727.post-90207622728931992612019-02-14T22:33:02.853+00:002019-02-14T22:33:02.853+00:00It depends on the scale you're going for. RKKV...It depends on the scale you're going for. RKKVs are on a completely different scale. Even at 10% of the speed of light, you're talking about energies over 2 million times greater per kg than my example. 'Relativistic' usually means when relativistic effects start becoming significant, so it's actually about 80% of the speed of light. <br /><br />To get to those velocities, you are best served by a laser or particle beam. The problem is that they get very low thrust per watt. So, for a decent acceleration, you need stupendous power levels.<br /><br />To get just 1 kg to 80% of the speed of light within one hour, you'd need a laser with an average output of several dozens of terawatts!. Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-43907878067282877462019-02-14T18:34:46.193+00:002019-02-14T18:34:46.193+00:00Sry not dean drive any drive which uses charged pa...Sry not dean drive any drive which uses charged particalsThe Librarianhttps://www.blogger.com/profile/01646848861149556379noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-49321769762864021202019-02-14T13:52:21.539+00:002019-02-14T13:52:21.539+00:00Thats impressive but its too heavy.
Actually i w...Thats impressive but its too heavy. <br /><br />Actually i want my RKKVs to at least look like the torpedos from The Expance. <br /><br />I know they are torch missiles so my missiles can never compete with them but as close as possible. <br /><br />What about a dean or m2p2 drive missile powered by partical beam from the ship, that should have more acclerarion and no propellant at all! Only the magnet. How could be the performance of this thing The Librarianhttps://www.blogger.com/profile/01646848861149556379noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-57270728114747277452019-02-09T20:41:58.966+00:002019-02-09T20:41:58.966+00:00Yes, you can.
For a torpedo, you would want to sac...Yes, you can.<br />For a torpedo, you would want to sacrifice some exhaust velocity to increase your thrust and acceleration. A torpedo that is two thirds propellant and with an exhaust velocity of 20km/s would have a deltaV of 21,900m/s. If we assume a 90% efficiency for its engine, each MegaWatt of laser power would give it 100 Newtons of thrust. <br /><br />We can therefore imagine a 10 ton torpedo with 6.66 tons of propellant, being driven by a 1,000 MW laser. It would accelerate at an average of 15m/s^2 and would reach a final velocity of 21.9km/s in 24 minutes. Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-33700566471840803972019-02-07T12:08:58.608+00:002019-02-07T12:08:58.608+00:00So the pellit ablation can give the highest perfor...So the pellit ablation can give the highest performance. Can this be made into a ship to ship torpedo using a much lower power laser(like which can be used in point defence). If yes then what could be the delta v and accleration of it. The Librarianhttps://www.blogger.com/profile/01646848861149556379noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-18877058974505888152017-09-19T14:32:15.411+01:002017-09-19T14:32:15.411+01:00There are many real world situations where countri...There are many real world situations where countries are forced to pick up the pieces and rebuild after a conflict blows up vital industrial and transport infrastructure. A lot of the money used to rebuild comes from insurance companies and debt made against the population and allies and/or 'vulture investors' who come to buy things while they're cheap. Examples include the WWII reconstruction effort, the collapse of Soviet Russia or more recently, Irak.<br /><br />Colonies are very likely to be self-sufficient with regards to life support, because it makes no economic sense to ship water and oxygen across interplanetary space when it can be made in-situ. What they're going to lack is spare parts, microprocessors and machinery needed to rebuild. <br /><br />Launch lasers doubling as the laser generators for a laser transport web, being converted into a laser weapon web by a military focusing 'terminal' was described in the Laser Weapon Web post as the most cost effective way of setting up the whole system. <br /><br />The launch laser will be tuned to whatever the atmosphere absorbs least. If it is a vacuum laser, there's still the problem of the mirrors being tuned to a specific wavelength, with reflectivity dropping rapidly outside of the allowed range. Turning it into a weapon will rely mostly on increasing the focus to destructive intensities. <br /><br />"I'm not trying to say any of this is inevitable, merely pointing out feasible and interesting situations for tough sci-fi.": That's what this is all about!Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-16298658194798551382017-09-19T03:58:39.820+01:002017-09-19T03:58:39.820+01:00I'm more concerned with the economic impacts o...I'm more concerned with the economic impacts of losing the biggest piece of infrastructure. They might not starve, but losing your very expensive launch facility might doom the colony in the long run if you can't find investment to rebuild. Perhaps somebody two continents down still has their launch facility, just found a great new vein of phosphorous, and has no record of pissing off people with warships. Colonies are unlikely to be self-sufficient and cheap surface to orbit/orbit to orbit is everything. <br /><br />I don't see why you wouldn't design your launch laser to be easily convertible for military use (if you have any safety/security concerns at all). Keep a secondary military optics array around that can focus the beam to a more useful spot size and voila, instant weapons platform that serves a useful function in peacetime. If you're using something broadly tunable like a free electron laser, you could destroy dangerous craft you are pushing by switching to a frequency that their engine will absorb destructively. You could hook such a system up to a laser web easily enough, cooling capabilities are vastly higher on a planetary surface. It's especially attractive for places without atmospheres to soak up beam energy, though that rules out air breathing propulsion. <br /><br />Yes, the "screaming in" is more a problem than the "GW plumes", I'm well aware. The tremendous amounts of energy involved in interplanetary travel make me think any polity will want strong control over craft that travel nearby. This could be beamed propulsion schemes, an Orbital Guard with serious firepower, government controlled "harbor pilot" software, or some combination of the three. It's a bit like if every plane flying today carried nuclear weapons that detonated in the event of a crash. Nobody much cares if you crash yourself in the Pacific, but if you're landing at an airport the government is going to watch you very carefully.<br /><br />I'm not trying to say any of this is inevitable, merely pointing out feasible and interesting situations for tough sci-fi.Final Iron Godnoreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-65338264484149240102017-09-17T23:14:54.645+01:002017-09-17T23:14:54.645+01:00You are right about every laser launch station dou...You are right about every laser launch station doubling as an ASAT weapon in a pinch, but I'm not sure that space colonies will become so dependent on laser launches.<br /><br />It might end up resembling modern global shipping. You need access to the sea and cock facilities to trade, make money and keep everyone happy. Destroying it will stop trade, but you can still be resupplied by seaplanes and helicopters. The SF analogy is a colony that has its laser launch system destroyed but is still connected to the rest of the solar system by rough-landing shuttles. <br /><br />If you have an enemy at your front door, whatever they really do doesn't matter as trade cannot continue in such a hostile environment. At the same time, slowly launching ships on a laser beam can't happen when enemies are in orbit. It's like fighter jets being shot down on the runway - they can't take off!<br /><br />The real problem with 'tramp freighters' is not the exhaust plume or even the output of their propulsion. It is the fact that even the slowest freighter can pack enough kinetic energy to rival nuclear weapons - a small 100 ton ship making a 'small' trip from the Earth to the moon can hit a lunar colony with 0.5*100000*3500^2: 612.5GJ of kinetic energy. It doesn't even need malicious intent. If the engines fail on a landing attempt, it'll smack down on the launchpad and the crater will gouge out the spaceport and surrounding colony! <br /><br />Nevermind the larger ships making faster journeys at 10, 20, 100km/s... Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-39291733384687036692017-09-17T02:15:13.519+01:002017-09-17T02:15:13.519+01:00Atomic Rockets pointed it out, I think, but this c...Atomic Rockets pointed it out, I think, but this concept has interesting strategic implications. Every spaceport is also a powerful defensive battery, tuned to dump GW of power on high altitude/orbital targets. This means its also likely to be the most valuable single target in a surface colony. They'd be dependent on laser launch for the import/export that makes the colony possible. This is a good plot hook for justifying surface combat. As an attacker, you want the spaceport, but its tough to attack from space (all equipment possible to bury would be buried deep underground or underwater and it can fry you) and too valuable to glass anyways. To take it, you need to land ground forces over the horizon and take the spaceport conventionally. Alternatively, you can sneakily sabotage the spaceport before approaching. This could be spies, bribed locals, Stuxnet-like industrial worms, timing your offensive for hurricane season, commando teams, etc. A great MacGuffin opportunity!<br /><br />These systems would also appeal to governments, who'd be happier with a system where they hold the throttle for every launch and landing and can vaporize offenders if need be. Sounds less risky than tramp freighters screaming in on GW plumes of possibly radioactive fire.Final Iron Godnoreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-19033173386275893102017-05-18T22:32:06.418+01:002017-05-18T22:32:06.418+01:00You know, I was thinking... what if we combined th...You know, I was thinking... what if we combined this system with the non-rotating skyhook? Then we can reduce the length of the skyhook and still get away with ridiculous payload mass fractions...BillPhilhttps://www.blogger.com/profile/01843292941195258105noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-90507045608272239512017-05-14T10:02:21.195+01:002017-05-14T10:02:21.195+01:00I don't really follow UFO theories. ToughSF tr...I don't really follow UFO theories. ToughSF tries to keep it within hard (realistic) science fiction, so everything I write is based on proven science.<br /><br />For example, boundary layer is just the closest layer of air to the vehicle, that interacts with its surface through viscosity. How can you 'take advantage' of it?<br /><br />Types of charge: positive, negative. There is no 'exotic' charge. <br /><br />Ultra speeds: how fast is that? <br /><br />Anti-gravity: .<br /><br />WIMPs: weakly interacting means that they barely affect anything. Using them for thrust is like trying to huff-puff your way into space. They don't form bubbles either.<br /><br />Inertially-independent: cancelling or lowering your inertia is strictly within the domain of 'soft' science fiction. Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-55668801864830560182017-05-13T21:02:16.825+01:002017-05-13T21:02:16.825+01:00Did Billy Meier call the Pleidian saucers "be...Did Billy Meier call the Pleidian saucers "beamships" for a reason? If you postulate a "beam forming in space" rather than on the ground you have some very different technological options. 1. Boundary Layer vehicles or vessels capable of taking advantage of the ionic nature of the atmospheric layers at extremely high altitude (50 plus kilometers) so that the "type of charge" around the vehicle as well as inside the vehicle's 'effective engine'..becomes pronounced. 2. Consider that Meier's friends may have had more than "simple electronic charges" on their surfaces...allow for the possibility of "exotic charge"...with everything that researchers in the 1950's like Thomas T. Browne were claiming...ultra speeds and anti-gravity capabilities. 3. With Terajoule beams...WIMP (weakly interacting massive particles) charges and special materials on the first few layers of a "saucer" (read 'inertially independant shapes')...then 40,000 mph in 2-3 seconds becomes possible...zero gravity stress inside that WIMP bubble. <br /><br />Looks good on paper anyway<br /><br />WWAnonymoushttps://www.blogger.com/profile/06567516623772479872noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-73901365347967012662017-04-08T16:45:21.372+01:002017-04-08T16:45:21.372+01:00Hi Nut Job!
1) I'm sorry, I could not find an...Hi Nut Job!<br /><br />1) I'm sorry, I could not find any recent cost per watt figures for high efficiency high power lasers.<br /><br />2) Since the pellet ablative rocket is a thermal rocket, its exhaust velocity depends on the square root of temperature over molar mass. Gold is 196g/mol, hydrogen atoms is 1g/mol. This means that exhaust velocity with hydrogen is 14 times lower than with gold, at the same temperature. <br /><br />I only mentioned gold as it was physically tested in laboratories for ablative propulsion, so we have 'hard' data on it. Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-13043162306587559632017-04-08T14:54:32.853+01:002017-04-08T14:54:32.853+01:00(1) Is laser price per Watt $10? you are quoting a...(1) Is laser price per Watt $10? you are quoting a decade old article. Arguably, this beamed power becomes attractive when cost goes below 1 $/W<br />(2) Pallet ablation sounds promising - but I doubt the switch from gold to hydrogen will give you the as much Isp as you hope: you quoted a table showing aluminum (atomic number 13) is not better than gold in this regard. Why would hydrogen do differently? And why not use carbon (6)?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-87720577943393822282017-03-25T13:15:53.533+00:002017-03-25T13:15:53.533+00:00A version extended into interstellar space? Excell...A version extended into interstellar space? Excellent! <br />I've been watching his videos recently. Slowly, because each one is quite long, but soon I'll be able to comment directly on a recent video. Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-55911573005435802512017-03-25T04:22:46.236+00:002017-03-25T04:22:46.236+00:00Issac Arthur takes the idea to "11": htt...Issac Arthur takes the idea to "11": https://www.youtube.com/watch?v=oDR4AHYRmlkThucydideshttps://www.blogger.com/profile/09828932214842106266noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-2261562419524495662017-03-14T07:07:49.982+00:002017-03-14T07:07:49.982+00:00I thought it was more like 2 seconds. I can't ...I thought it was more like 2 seconds. I can't imagine a laser can stay in that sail for two minutes. Yet still one zap is all we get. If it's not exact, then hello Banard's Star, or wind up in the middle of lost in space. Planetwatcherhttps://www.blogger.com/profile/14449027801037636448noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-77769941081782558252017-03-13T08:19:51.357+00:002017-03-13T08:19:51.357+00:00You're missing a critical point: the probe rea...You're missing a critical point: the probe reaches its final velocity in two minutes. 60000G-force applied by a 100GW laser to a 1 gram micro-chip.Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-77940682451860837142017-03-13T08:06:53.940+00:002017-03-13T08:06:53.940+00:00This conversation reminds me of Starshot. The conc...This conversation reminds me of Starshot. The concept seems sound, but yet very power consuming, and would require almost microscopic accuracy. Can we be so accurate to have something moving with Earth, blast a ray at an object in space moving differently? Then have it launch said object in a desired direction at a desired speed, compensating for fluctuations and weather in the atmosphere. Then where to locate the ground based lasers. I read that starshot will do it from the Equator, but if you're going celestial south (to Alpha C.) that's a lot more atmosphere to penetrate, compared to shooting it from New Zealand. Wouldn't putting that laser on a rocket be far better, and fire from much closer? How nice it would be if it worked. Planetwatcherhttps://www.blogger.com/profile/14449027801037636448noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-48120179229355706942017-03-13T07:36:24.940+00:002017-03-13T07:36:24.940+00:00Took some searching, but I found an article on the...Took some searching, but I found an article on the concept: http://www.nextbigfuture.com/2017/01/bae-wants-to-enhance-reflective.html<br /><br />BAE trusts that they can do it, so I think it is possible.Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-27009023925273763462017-03-11T22:47:00.258+00:002017-03-11T22:47:00.258+00:00How possible is it for a laser to produce an atmos...How possible is it for a laser to produce an atmospheric distortion? Diffraction for anti- laser work, for example. Geoffrey S Hnoreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-88898826993571123922017-03-08T19:42:13.747+00:002017-03-08T19:42:13.747+00:00Thank you for clarification!Thank you for clarification!Dilanduhttps://www.blogger.com/profile/18106983467449117490noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-37126517738180188052017-03-08T18:21:03.030+00:002017-03-08T18:21:03.030+00:00http://ieeexplore.ieee.org/document/1073096/
An o...http://ieeexplore.ieee.org/document/1073096/<br /><br />An old concept with maximum theoretical efficiency of 0.2%.... it won't ever be cost effective if electrical power stations are sitting on the ground, just 100km away.Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-89246658070323584922017-03-08T16:29:05.139+00:002017-03-08T16:29:05.139+00:00True... Hm. I'm not laser expert by any means,...True... Hm. I'm not laser expert by any means, but I could recall the concept of solar-pumped laser on iodine. I wonder: would such kind of laser be more cost-effective as orbital launch facility than more "conventional" solar-to-electricity lasers?Dilanduhttps://www.blogger.com/profile/18106983467449117490noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-35939739193855792992017-03-07T14:04:28.057+00:002017-03-07T14:04:28.057+00:00Quite true. However, it will be the most expensive...Quite true. However, it will be the most expensive to set up. Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.com