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#31
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Towards routine, reusable space launch.
In article , droleary@
2017usenet1.subsume.com says... For your reference, records indicate that Jeff Findley wrote: Sure, sure, Star Trek style transporters with infinite range. I'll get right on that. No, you won?t. But you apparently *will* use it as a straw man to avoid actually addressing the likelihood that new technologies developed in the future will change the economies of space launches. Hell, that?s essentially what SpaceX is demonstrating today. Bull****. SpaceX is not demonstrating any new technologies. They've combined existing technologies in novel ways to solve the problems involved in building Merlin engines and Falcon launch vehicles. There is zero new tech in them. If you believe differently, name a new technology they're using in their engines, launch vehicles, Dragon, and etc. The fact is that any other engine manufacturer, launch vehicle provider, and spacecraft manufacturer could have done the same things. In fact, Blue Origin *is* doing much the same with New Glenn. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
#32
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Towards routine, reusable space launch.
Doc O'Leary wrote on Sat, 9 Jun
2018 17:19:39 -0000 (UTC): For your reference, records indicate that Fred J. McCall wrote: Doc O'Leary wrote on Fri, 8 Jun 2018 13:10:48 -0000 (UTC): What are the actual numbers when it comes to savings from a reusable rocket? That depends on a lot of things. Well, sure, but it always helps to have some data to work with before beginning an optimization process. Best/worst cases or averages or whatever. What the savings is related to the total cost of the launch is going to be guiding factor on how much effort it makes sense to expend to re-use different parts of the system. When I say it depends on a lot of things, I meant exactly that. You can't 'invent' data. Space Shuttle was supposedly 'partly reusable', but it was MORE expensive than throwing away hardware with similar capabilities. SpaceX seems to think that they can reduce the cost of a launch by a third by reusing first stages (and that was before they were optimized for reuse). They think that BFR/BFR Spaceship will cost less than 1% of the hardware price per flight (a fully reusable system good for 100 launches before servicing). Pick your poison. It?d also be interesting to know how new technologies might impact the economics of launching items into space (including just making disposable launch vehicles much cheaper). Real reuse will always be cheaper. If you can make disposable launch vehicles much cheaper, the same technologies allow making reusable launch vehicles much cheaper. That is non-obvious. Ideally, I would think a “zero waste” system would be cheapest; every kg of mass that gets sent up either stays up (doing something useful) or was the fuel. All this booster landing (and subsequent refurbishing for relaunch) we’re seeing, while cool, is definitely *not* the most efficient use of resources. Yes, magic would be more efficient, but we don't have magic. Once you start to contemplate the need for multiple daily launches, even recovering boosters to reuse them seems like a slow and labor-intensive process. But orders of magnitude faster than throwing them away and building a new one. But that’s still assuming old technologies rather than new ones. You don’t “throw away” a space elevator. You also can't build one without 'magic' because it is impossible for materials to be strong enough. Nor a mag-lev cannon. Now the payload needs to be 'magic' to withstand the launch. I’m not sure how viable a high-altitude balloon launch would be, but it may also be cheaper than traditional first-stage rockets. I'm sure. It doesn't accomplish what a first stage accomplishes, so it doesn't really matter if it's cheaper or not. What it's not is 'effective'. On the path to a space elevator, it seems like there should be many more ways to reach escape velocity that do a better job than what Musk is doing today. You've discovered a good supply of unobtainium, have you? Otherwise, rockets are your man for getting stuff to orbit for the foreseeable future. It’s always a good idea to noodle around with other technologies, no matter how impossible they appear to be today. Building a tether on Earth requires materials that are stronger than materials can theoretically be. Noodle all you like. Basic laws of physics aren't going to change no matter how hard you wish. Because, yes, rockets are the way to get to orbit, but I’m most interested in the *unforeseeable* future that has humans on other planets around other stars. Just being satisfied with rockets is not going to make that happen. When you're in entirely the wrong newsgroup. You need something that starts with 'alt' or 'rec'. -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
#33
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Towards routine, reusable space launch.
On Jun/12/2018 at 5:36 PM, Fred J. McCall wrote :
Doc O'Leary wrote on Tue, 12 Jun 2018 15:00:13 -0000 (UTC): For your reference, records indicate that Fred J. McCall wrote: Doc O'Leary wrote on Mon, 11 Jun 2018 22:35:20 -0000 (UTC): Chicken and egg. The fact is that we *do* sometimes have to elaborately engineer spacecraft in order to make them small enough to fit into a nose cone or payload bay of a rocket. Head and ass. Cite for such payloads? Be specific. You're posting into a 'sci' newsgroup. Handwavium is not sufficient. Then I must say I note a lack of citations for your own claims. I haven't made any claims. Mine are easy enough to demonstrate. I can literally link to just about *any* payload that unfolds to deploy as evidence. Let’s start with the obvious: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#/media/File:JWST_launch_configuration.png Not a good example. Things like solar arrays are launched folded because they can't take acceleration without snapping off, not because they're 'too bulky'. Try again? The telescope is folded, not only the solar arrays. Alain Fournier |
#34
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Towards routine, reusable space launch.
Alain Fournier wrote on Tue, 12 Jun 2018
20:08:10 -0400: On Jun/12/2018 at 5:36 PM, Fred J. McCall wrote : Doc O'Leary wrote on Tue, 12 Jun 2018 15:00:13 -0000 (UTC): For your reference, records indicate that Fred J. McCall wrote: Doc O'Leary wrote on Mon, 11 Jun 2018 22:35:20 -0000 (UTC): Chicken and egg. The fact is that we *do* sometimes have to elaborately engineer spacecraft in order to make them small enough to fit into a nose cone or payload bay of a rocket. Head and ass. Cite for such payloads? Be specific. You're posting into a 'sci' newsgroup. Handwavium is not sufficient. Then I must say I note a lack of citations for your own claims. I haven't made any claims. Mine are easy enough to demonstrate. I can literally link to just about *any* payload that unfolds to deploy as evidence. Let’s start with the obvious: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#/media/File:JWST_launch_configuration.png Not a good example. Things like solar arrays are launched folded because they can't take acceleration without snapping off, not because they're 'too bulky'. Try again? The telescope is folded, not only the solar arrays. And THAT is because you cannot make a single mirror that large to adequate precision, so once it's in pieces you might as well fold the sucker up. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
#35
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Towards routine, reusable space launch.
JF Mezei wrote on Wed, 13 Jun 2018
02:15:38 -0400: On 2018-06-12 19:00, Jeff Findley wrote: Bull****. SpaceX is not demonstrating any new technologies. Is friction fit welding for the tanks a first for rockets? I know it isn't "new" since it was used by Airbus and others, but wondering if it was first use in rockets/tanks. I suspect it was used for wheels on rail cars and other similar things long before it was used on aircraft (and frankly it seems a poor fit for aircraft use). Since SpaceX is developping composite tanks for BFR, was there any though of puttting composite tanks for Block 5 Falcon 9? Just wondering if there would be a big payback in weight or if the difference not worth the trouble of developping/testing/certifying such a tank. I doubt it. They were more interested in fixing the existing COPV design than grounding waiting for a whole new technology. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
#36
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Towards routine, reusable space launch.
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#37
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Towards routine, reusable space launch.
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#38
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Towards routine, reusable space launch.
For your reference, records indicate that
Jeff Findley wrote: In article , droleary@ 2017usenet1.subsume.com says... For your reference, records indicate that Jeff Findley wrote: Sure, sure, Star Trek style transporters with infinite range. I'll get right on that. No, you won?t. But you apparently *will* use it as a straw man to avoid actually addressing the likelihood that new technologies developed in the future will change the economies of space launches. Hell, that?s essentially what SpaceX is demonstrating today. Bull****. SpaceX is not demonstrating any new technologies. They've combined existing technologies in novel ways to solve the problems involved in building Merlin engines and Falcon launch vehicles. There is zero new tech in them. If you believe differently, name a new technology they're using in their engines, launch vehicles, Dragon, and etc. Sigh Of *course* there’s no “new technology” in *anything* that’s in the world today. Your engineering mindset has you in a motivated reasoning spiral. The fact remains that, over the course of time, new technologies have been developed that have made their way into space programs. SpaceX is taking advantage of some of those technologies today. It is a safe bet that such innovations will occur in the future, and somebody will take advantage of them. -- "Also . . . I can kill you with my brain." River Tam, Trash, Firefly |
#39
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Towards routine, reusable space launch.
Doc O'Leary wrote on Wed, 13 Jun
2018 12:57:19 -0000 (UTC): For your reference, records indicate that Jeff Findley wrote: In article , droleary@ 2017usenet1.subsume.com says... For your reference, records indicate that Jeff Findley wrote: Sure, sure, Star Trek style transporters with infinite range. I'll get right on that. No, you won?t. But you apparently *will* use it as a straw man to avoid actually addressing the likelihood that new technologies developed in the future will change the economies of space launches. Hell, that?s essentially what SpaceX is demonstrating today. Bull****. SpaceX is not demonstrating any new technologies. They've combined existing technologies in novel ways to solve the problems involved in building Merlin engines and Falcon launch vehicles. There is zero new tech in them. If you believe differently, name a new technology they're using in their engines, launch vehicles, Dragon, and etc. Sigh Of *course* there’s no “new technology” in *anything* that’s in the world today. Your engineering mindset has you in a motivated reasoning spiral. The fact remains that, over the course of time, new technologies have been developed that have made their way into space programs. SpaceX is taking advantage of some of those technologies today. It is a safe bet that such innovations will occur in the future, and somebody will take advantage of them. And it's an even safer bet that none of those 'new technologies' are going to replace "throwing stuff aft to move forward". A space elevator on Earth requires not 'new technology', but 'new physics'. -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
#40
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Towards routine, reusable space launch.
Jeff Findley wrote on Wed, 13 Jun 2018
06:41:27 -0400: In article , says... Because, yes, rockets are the way to get to orbit, but I?m most interested in the *unforeseeable* future that has humans on other planets around other stars. Just being satisfied with rockets is not going to make that happen. When you're in entirely the wrong newsgroup. You need something that starts with 'alt' or 'rec'. Unfortunately, rec.arts.sf.science is in the stupid distribution list of the posts in this thread. I've removed it from this reply. I know where the git is posting from. I'm trying to make the point that he shouldn't be posting HERE. -- You are What you do When it counts. |
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