tag:blogger.com,1999:blog-7494544263897150929.post2540336854694064471..comments2024-03-18T13:11:39.192-07:00Comments on Rocketpunk Manifesto: Temperate and Indecisive ContestsRickhttp://www.blogger.com/profile/16932015378213238346noreply@blogger.comBlogger236125tag:blogger.com,1999:blog-7494544263897150929.post-43255900559368694702010-11-15T21:46:39.437-08:002010-11-15T21:46:39.437-08:00Would the 50s era Soviets conceptualize a gun capa...<i>Would the 50s era Soviets conceptualize a gun capable of firing a 4000 kg shell over intercontinental range?</i><br /><br />Given the Soviet (and Russian) interest in the gargantuan, something along these lines might have been arranged.Thucydideshttps://www.blogger.com/profile/09828932214842106266noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-77990921351373907572010-11-15T16:26:20.474-08:002010-11-15T16:26:20.474-08:00Not a whole lot to add!
Would the 50s era Soviets...Not a whole lot to add!<br /><br />Would the 50s era Soviets conceptualize a gun capable of firing a 4000 kg shell over intercontinental range?Rickhttps://www.blogger.com/profile/16932015378213238346noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-23820974177113558472010-11-15T12:34:24.262-08:002010-11-15T12:34:24.262-08:00Thinking of contrafactuals
Rocket artillery is fa...Thinking of contrafactuals<br /><br />Rocket artillery is fairly old (the Chinese and Koreans used a form of rocket artillery against the Japanese in the 1500's), but has never had a reputation for accuracy. The "Rocket's red glare" over Fort McHenry must have looked pretty impressive, but rocket artillery was only an area weapon, and even today, most rocket artillery is designed to blanket a grid square with fire and destruction rather than hit pinpoint targets.<br /><br />Gun artillery, OTOH, is relatively accurate "out of the box", and has multiple virtues, including relatively cheap ammunition, quick response time and a high degree of flexibility. If the Paris gun was linked to a forward observer, it might have been far more devastating. A rocket, OTOH, needs expensive and sophisticated guidance equipment on board to have a high degree of accuracy, which wasn't possible until the early 1940's.<br /><br />If weapons like the Paris gun had not been specifically banned by the Treaty of Versailles, then the German Army might not have had any incentive to look at the VfR and von Braun's work. Weapons like the V3 (High Pressure Gun, AKA millipede) would have been developed instead and the war might have been marked by sieges using such weapons to devastate London, Moscow, Leningrad etc. The idea of using developed versions of these guns to launch some sort of small satellite package into orbit might have occurred to someone, and the Space age would have been born on the blast of super artillery pieces rather than a rocket.Thucydideshttps://www.blogger.com/profile/09828932214842106266noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-46932030197423852332010-11-15T07:15:21.199-08:002010-11-15T07:15:21.199-08:00Forgot about Gerald Bull - too clever for his own ...Forgot about Gerald Bull - too clever for his own good.<br /><br />Rockets always had a place in the artillery picture, but I think artillerists regarded them as basically self propelled mortar rounds, not remotely a substitute for long range precision fire.<br /><br />Orbital guns would be totally unsuited to human spaceflight, but that is just the point. We got orbital rockets instead of orbital guns basically because of space geeks.Rickhttps://www.blogger.com/profile/16932015378213238346noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-86939340434234515822010-11-14T22:22:40.371-08:002010-11-14T22:22:40.371-08:00The Scottish group ASTRA did research into hyperso...The Scottish group ASTRA did research into hypersonic waveriders and published some papers which indicated that a form of parafoil might be the best and most economical means of using the waverider form for high speed flight (especially reentry.)<br /><br />Since the ship resembled a Rogallo wing hang glider it could be essentially packed up in folded configuration during launch, and also adjust the shape to meet different flight regimes (since waveriders are very sensitive to speed, the mach 25 re-entry shape would not work very well at mach 6). The light weight and low wing loading would give it better flight performance.<br /><br />As for long range weapons, there is a chance that without von Braun and others, long range artillery would actually <b>be</b> artillery. The Paris Gun of WWI fame could fire giant shells to a maximum design range of 130km, and even railway cannons of WWII had effective ranges as far as 50km. Gerald Bull was hoping to achieve actual orbital launch using a gun, and there is no particular reason to think this is impossible.<br /><br />Of course, manned spaceflight would be effectively impossible if giant tube artillery was the means of launching spacecraft into orbit...Thucydideshttps://www.blogger.com/profile/09828932214842106266noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-40690393864183201082010-11-06T20:47:16.449-07:002010-11-06T20:47:16.449-07:00The first generation ICBMs weren't built as sp...The first generation ICBMs weren't built as space boosters, but they applied concepts and solutions initially worked out for space access. <br /><br />Von Braun is the premier embodiment of this whole process. <br /><br /><i>'Ze rockets go up; who knows vere they come down: Zat's not my department,' says Wehrner von Braun.</i> <br /><br />He would build anyone a rocket to do anything, but what HE was interested in was outer space. <br /><br />Counterfactuals are untestable, but I think the use of rockets to hit targets hundreds or thousands of km distant would have emerged without that human catalyst.Rickhttps://www.blogger.com/profile/16932015378213238346noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-37768819972556774042010-11-06T20:00:46.461-07:002010-11-06T20:00:46.461-07:00I know that. However, you won't launch in adv...I know that. However, you won't launch in adverse weather, and you can control where you come down to avoid it. I was suggesting it as an alternative to parachutes (light, small, uncontrollable) and wings (large mass penalties). It might be better for reentry vehicles than the first stage, though.Byronhttps://www.blogger.com/profile/07778896782683765138noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-23099312817617670072010-11-06T19:51:37.603-07:002010-11-06T19:51:37.603-07:00Byron:
The X-38 used a parafoil for its landing m...Byron:<br /><br />The X-38 used a parafoil for its landing mechanism. Automated, even. The drop test went well, but the program was cancelled anyway due to budget cuts.<br /><br />IIRC, though, parafoils don't have the tolerance of weather conditions that winged vehicles do. It may be a good place to start, but I think the additional flexibility and cross-range of wings would be better suited to a recoverable first stage in the longer term.Raymondhttps://www.blogger.com/profile/18103471451043461302noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-7307065062986885302010-11-06T09:58:50.075-07:002010-11-06T09:58:50.075-07:00They weren't built that way because that was t...They weren't built that way because that was the best way of building space boosters. They were built like that because that was the fastest way of getting a workable ICBM. An ICBM must be close to being able to achieve orbit, and initially, they had to use liquid fuel because that was what was available. Later, they switched to missiles that were solid-fueled because that was better for ICBMs. However, it's not as good for space launch, except when you get it surplus.Byronhttps://www.blogger.com/profile/07778896782683765138noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-28238248999005277912010-11-06T09:55:42.698-07:002010-11-06T09:55:42.698-07:00Pulling up a comment of Tony's from a few days...Pulling up a comment of Tony's from a few days ago to make an important quibble:<br /><br /><i>And, BTW, ICBMs would have existed without spaceflight. They were developed without anything to do with space in mind. They were simply an extension of artillery, going all the way back to the V-2.</i><br /><br />But would there have been a V-2 without Oberth, the VfR, and von Braun? Left to themselves I think the artillery people would have gone much more the direction of the Katyusha than the V-2 ... and for good reason, since the Katyusha was a FAR more useful weapon system.<br /><br />The idea of building enormous multistage rockets was a creation of space geeks, and might not have emerged without them. It is highly indicative that the first generation Russian and American ICBMs were liquid fueled and thoroughly unsatisfactory as missiles, but descendents of both are still in use as space boosters.Rickhttps://www.blogger.com/profile/16932015378213238346noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-13970738706400365002010-11-06T09:38:36.337-07:002010-11-06T09:38:36.337-07:00Gemini was originally planned to land on runways w...Gemini was originally planned to land on runways with a paraglider, but that got cut during development. More information can be found <a href="http://www.astronautix.com/craft/gemlider.htm" rel="nofollow">here</a>. I personally think that paragliders are underrated as a way of recovering stuff. It allows many of the advantages of an airplane without the enormous design penalties.Byronhttps://www.blogger.com/profile/07778896782683765138noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-89482031520461491582010-11-06T08:40:14.001-07:002010-11-06T08:40:14.001-07:00What Ferrell said. Anyway we have a much more rele...What Ferrell said. Anyway we have a much more relevant contemporary example, the recovery of the SRBs. Here's a <a href="http://www-pao.ksc.nasa.gov/kscpao/nasafact/ships.htm" rel="nofollow">fact sheet</a> with a few details. There are 2 recovery ships, one per booster; each is 1000 tons and has a crew of 24.<br /><br />These are solids, so the rest of the refurbishment process is very different, but this should provide some baseline on the cost of the recovery operation, and the effect of splashdown on the booster.<br /><br />In principle this is a straightforward tradeoff between the additional mass penalty (and development cost) of putting wings and landing gear on a first stage, versus the recovery cost and added refurbishment cost.<br /><br />I think there is a subtle bias against parachute recovery (especially of crews, more than boosters, etc.) because of its association with bailing out of crippled planes - only skydivers and paratroops deliberately hit the silk. But for spacecraft it is a simple way to soft land on a planet with a dense atmosphere, and wings don't really add that much.<br /><br />I would also think that our ability to guide parachute descents is much greater than in the 1960s, though maneuver may be problematic for heavy payloads under giant chutes.Rickhttps://www.blogger.com/profile/16932015378213238346noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-18280944323124443922010-11-05T17:38:55.302-07:002010-11-05T17:38:55.302-07:00Tony said:"Just a boat, huh? I suggest you go...Tony said:"Just a boat, huh? I suggest you go back to your readings and pay a little closer attention to the size and composition of the naval task forces considered necessary to ensure the safe and timely recovery of three men in one module, even if they landed in roughly the right spot."<br /><br />Most of that was showmanship and national prestige; we not only sent men to the moon, but we could afford an entire Carrier Battle Group to retreve them...<br /><br />FerrellAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-90014686902775556942010-11-05T12:55:29.984-07:002010-11-05T12:55:29.984-07:00Jim Baerg:
"I just finished pointing out tha...Jim Baerg:<br /><br /><i>"I just finished pointing out that with 1960s technology they could land within a few km of the desired location. There is no reason re-entries can not be timed so that all your vehicles splash down in the same small region & you only need one boat regularly traveling from a nearby harbour to that region."</i><br /><br />Just a boat, huh? I suggest you go back to your readings and pay a little closer attention to the size and composition of the naval task forces considered necessary to ensure the safe and timely recovery of three men in one module, even if they landed in roughly the right spot.Tonyhttp://blogs.echofiveecho.comnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-88948873137809304052010-11-04T22:09:40.790-07:002010-11-04T22:09:40.790-07:00"Parachute recovery requires a recovery force..."Parachute recovery requires a recovery force and acceptance of landing in a semi-random location"<br /><br />I just finished pointing out that with 1960s technology they could land within a few km of the desired location. There is no reason re-entries can not be timed so that all your vehicles splash down in the same small region & you only need one boat regularly traveling from a nearby harbour to that region.Jim Baergnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-67855829351709456762010-11-04T19:37:49.897-07:002010-11-04T19:37:49.897-07:00Jim Baerg:
"If you have a 2 stage to orbit r...Jim Baerg:<br /><br /><i>"If you have a 2 stage to orbit rocket the extra mass of a heat shield to allow reentry & recovery may mean you are better off keeping the 2nd stage in orbit for use there. The notion of turning propellant tanks into extra living & working space on a space station has always sounded good to me."</i><br /><br />Conversion of launch vehicle tankage to pressurized volume on orbit may not be that economical. It's not properly insulated, it doesn't have docking interfaces, it doesn't have an electircal power, it doesn't have intercommunications capability, etc. Of course, one could design tankage that could be converted with a simple toolkit and supply an interior outfitting kit as part of the payload -- but that just eats up payload.<br /><br />Also, who's going to use such converted volume? Space stations have even less economic validity in the future than they do today. People are going to be going to Mars to explore and maybe live, and to the rest of the solar system to explore. And it's going to be that way for the next two or three hundred years, maybe longer. So they're not going to need space stations. They're going to man spacecraft assembled by docking separately launched modules from Earth. Stations are wasted launch capacity. Maybe a case could be made for incorporating upper stage tankage in interplanetary spacecraft, if a way can be found to make the conversion process, safe and reliable.<br /><br /><i>"According to this wikipedia article all the Apollo capsules landed within 10 km of the intended point. So for anything you want to get from space (eg: returning people, platinum mined from the moon, stuff needing zero gee for manufacture) something like Apollo capsules & parachutes could be aimed at a patch of ocean close to a good harbour for the recovery vessel."</i><br /><br />Parachute recovery requires a recovery force and acceptance of landing in a semi-random location. (Not always at sea.) Winged or lifting body recovery enables smaller recovery forces (only needed for an emergency) and larger cross-range capability, in exchange for some payload mass.<br /><br />BTW...<br /><br />"[S]tuff needing zero gee for manufacture" is a myth. Gravity is actually one of our most useful tools. Microgravity has yet to be proven to be a unique manufacturing environment for <b>anything</b>, even in theory. The whole idea, like satellite recovery, was just speculative nonsense dreamed up to justify Shuttle and Space Station Freedom.<br /><br />Platinum from the Moon? How rare do we suppose platinum (ore or recycled) needs to be on Earth to economically justify that?Tonyhttp://blogs.echofiveecho.comnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-57328552190994032142010-11-04T18:18:54.680-07:002010-11-04T18:18:54.680-07:00Raymond:
I'll concede you may have a point for...Raymond:<br />I'll concede you may have a point for the bottom stage of a rocket, since the extra mass doesn't have to be accelerated to quite such a high speed as the upper stages.<br /><br />If you have a 2 stage to orbit rocket the extra mass of a heat shield to allow reentry & recovery may mean you are better off keeping the 2nd stage in orbit for use there. The notion of turning propellant tanks into extra living & working space on a space station has always sounded good to me.<br /><br />According to <a href="http://en.wikipedia.org/wiki/Splashdown_(spacecraft_landing)" rel="nofollow">this</a> wikipedia article all the Apollo capsules landed within 10 km of the intended point. So for anything you want to get from space (eg: returning people, platinum mined from the moon, stuff needing zero gee for manufacture) something like Apollo capsules & parachutes could be aimed at a patch of ocean close to a good harbour for the recovery vessel.Jim Baergnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-25444703532328315532010-11-03T20:15:40.718-07:002010-11-03T20:15:40.718-07:00Raymond:
"Wings, landing gear etc allow for ...Raymond:<br /><br /><i>"Wings, landing gear etc allow for self-recovery, saving the cost of specialized barges and tranfer equipment. The booster can land at a convenient airstrip. And extra mass in the first stage is more easily compensated for without substantial performance penalties."</i><br /><br />Well, there are all sorts of technical tradeoffs to be made, but on a first approximation it certainly seems like wings make more sense than parachuting into the sea. Wings are also more operationally flexible for a launch vehicle component you might want to actually market worldwide -- not everybody launches from the Atlantic Missile Range.Tonyhttp://blogs.echofiveecho.comnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-29296222334546612062010-11-03T19:33:23.263-07:002010-11-03T19:33:23.263-07:00Wings, landing gear etc allow for self-recovery, s...Wings, landing gear etc allow for self-recovery, saving the cost of specialized barges and tranfer equipment. The booster can land at a convenient airstrip. And extra mass in the first stage is more easily compensated for without substantial performance penalties.Raymondhttps://www.blogger.com/profile/18103471451043461302noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-37640588790752168312010-11-03T19:23:18.913-07:002010-11-03T19:23:18.913-07:00I doubt the usefulness of wings on reusable rocket...I doubt the usefulness of wings on reusable rocket stages. They are a lot of extra mass to boost. Parachuting to a splashdown seems to me to be the lowest mass way to have a sufficiently soft landing that the rocket stage suffers negligible damage.Jim Baergnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-31429357007676802272010-11-03T15:49:42.624-07:002010-11-03T15:49:42.624-07:00Rick:
"By flyback boosters do you just mean ...Rick:<br /><br /><i>"By flyback boosters do you just mean putting wings on the 1st stage and gliding it back? Or airdropping at Mach 3 instead of Mach 0.75?"</i><br /><br />Wings, flight controls, landing gear, etc. on a liquid-fueled, vertical take-off first stage. It's a concept <a href="http://buzzaldrin.com/space-vision/rocket_science/starbooster/" rel="nofollow">Buzz Aldrin has been promoting</a> for a decade now, at least.<br /><br />Since the booster's job is simply to get the upper stages above most of the atmosphere and impart the first few thousand kph of velocity, its required performance envelope is relatively limited and compact. It's also the first thing to go on the way up. Adding recoverability to the booster increases the mass and complexity of the booster, but that's all it does in mass terms. It may take a bigger booster to get to a nominal altitude and velocity, because the booster has to lift the mass of it's recovery gear as well as everything else. But when you get there, the upper stages and the payload don't need to be any bigger than they would have been with a single-use first stage.Tonyhttp://blogs.echofiveecho.comnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-88634411127995681212010-11-03T14:46:58.026-07:002010-11-03T14:46:58.026-07:00By flyback boosters do you just mean putting wings...By flyback boosters do you just mean putting wings on the 1st stage and gliding it back? Or airdropping at Mach 3 instead of Mach 0.75?<br /><br />Back in the 50s the von Braun proposal had winged lower stages, and I vaguely recall talk of putting wings on the Saturn V first stage.<br /><br />Pretty much all the alternative launch strategies have the same scaling problem. They all require enormous front end investment, justified only if you can count on an enormous launch traffic.Rickhttps://www.blogger.com/profile/16932015378213238346noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-15392368375437229532010-11-03T08:51:10.892-07:002010-11-03T08:51:10.892-07:00Re: beamed launch vehicle power
The problem with ...Re: beamed launch vehicle power<br /><br />The problem with beamed power is that it's not downscalable. To lift your first payload of a given mass, you have to build an entire integrated system that only makes economic sense for hundreds or even thousands of payloads a year. After Shuttle, your investors (even government investors) are going to want to see a confirmed manifest of hard-to-escape launch service contracts, equivalent to at least half of the break-even volume for five to ten years.<br /><br />That's not realistic, Tony. That's not fair. Sorry, guys, we're not in business to lose our shirts pursuing your dream. Show me the money.Tonyhttp://blogs.echofiveecho.comnoreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-44388745405720431012010-11-02T21:46:53.410-07:002010-11-02T21:46:53.410-07:00The only thing I would consider as potential "...The only thing I would consider as potential "IC" technology for spaceflight in the plausibel mid future (tm) would be beamed power, and even then I would add the caveat that we are talking about Liek Myrabo's "Lightcraft" which use a simple(?) annular mirror to focus laser energy on the air (while the spacecraft is accelerating to orbit) and remass once in vacuum.<br /><br />While the spacecraft would be made to very high tolerances for the laser focus to perform as advertised, the overall concept is far lighter, simpler and has fewer moving parts etc. to go wrong. The heavy and complex part is on the ground where the crew can get to it for maintainance and repair.<br /><br />Massive momentum exchange tethers are more like railroads, and other things like the JP Aerospace balloon spacecraft are rather implausible (although not impossible [I don't think]). Myrabo's other projects involving MHD accelerators driven by high energy microwave beams might be possible, but are much more complex and don't fall under "IC" tech.Thucydideshttps://www.blogger.com/profile/09828932214842106266noreply@blogger.comtag:blogger.com,1999:blog-7494544263897150929.post-3224526071380979922010-11-02T18:31:51.149-07:002010-11-02T18:31:51.149-07:00Ferrell:
"So...a late 21st century rocket ma...Ferrell:<br /><br /><i>"So...a late 21st century rocket made with graphene and fueled by metastable metallic hydrogen might just be the breakethroughs that are needed to bring the cost-of-launch down enought to bring it withing reach of people other than large coporations or the super-rich...to bad I'll probably be dead by then...:("</i><br /><br />No reason to fret. All credible macro applications of graphene involve attachment to substantial substrates. Monolithic graphene structures, like fuel tankage, are simply magitech. The same goes for metastable metalic hydrogen.Tonyhttp://blogs.echofiveecho.comnoreply@blogger.com