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#41
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Towards routine, reusable space launch.
JF Mezei wrote on Wed, 13 Jun 2018
16:28:16 -0400: On 2018-06-13 06:46, Jeff Findley wrote: In article , Composite structures/tanks are also not new. Composites are heavily used in aerospace. For space specifically, the X-33 program designed and built cryogenic composite tanks. They failed during testing... Have cryogenic fuel/O2 tanks made solely of composites ever been sucesfully used in production rockets? If BFR manages to have all composite tanks that work, doesn't that constitute innovation? 'Innovation' using an existing technology. Composites were not new to airplanes. But Boeing (with NASA funding) developped the tech and knowledge of how to produce single piece sections of fuselages, complete with the stringers (787 programme). While the material was not new, its application was. So it was existing technology. -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
#42
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Towards routine, reusable space launch.
On Jun/13/2018 at 5:35 PM, Fred J. McCall wrote :
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'. It would be possible to build a space elevator using materials available today without any major new technology. But that wouldn't be economical. Not even remotely close to being economical. New materials would be needed to build a sane space elevator, but new physics isn't needed. See for instance http://space.nss.org/media/2000-Spac...A-CP210429.pdf Alain Fournier |
#43
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Towards routine, reusable space launch.
JF Mezei wrote on Wed, 13 Jun 2018
17:55:45 -0400: On 2018-06-13 17:35, Fred J. McCall wrote: And it's an even safer bet that none of those 'new technologies' are going to replace "throwing stuff aft to move forward". Now now. We already know we'll test drive warp drive in 2063. They've even already made a movie about it. (and on same day, we meet the Vulcans in northern USA (I think it was Montana). I'm sure that makes perfect sense to 'Doc'. Until then, the accelerate mass backwards" may remain primary mode of propulsion, but there could still be much innovation in how you do it. Out of curiosity, if you detonated an atomic bomb inside an engine bell (assume engine bell is infinitely strong). Not how you want to do it. does f=ma stll apply in terms of the mass being limited to the mass of the bomb? Or do many other factors kick in in a nuclear explosion because mass doesn't remain constant? Pretty much yes, although you'd probably get a decent 'photon drive' component. Is knowledge enough today that would allow micro nuclear explosions that can be focused in trhowing its mass backwards at very high speed? (aka: regular micro explosions to slowly accelerate ship) This technology was investigated over half a century ago. See? Existing technology. https://en.wikipedia.org/wiki/Projec...ear_propulsion) Or must one have critiocal mass of nuclear material to cause an exlosion so the smallest explosioon that can happen is HUGE ? Forty tons (the smallest bomb we built in the 1950's) is not particularly 'huge'. In fact, it was regarded as too small for anything but an orbital test program. -- "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 |
#44
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Towards routine, reusable space launch.
Alain Fournier wrote on Wed, 13 Jun 2018
19:39:10 -0400: On Jun/13/2018 at 5:35 PM, Fred J. McCall wrote : 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* theres no new technology in *anything* thats 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'. It would be possible to build a space elevator using materials available today without any major new technology. But that wouldn't be economical. Not even remotely close to being economical. New materials would be needed to build a sane space elevator, but new physics isn't needed. See for instance http://space.nss.org/media/2000-Spac...A-CP210429.pdf I recall reading at least some analyses that said that the tensile strength required exceeded atomic forces (in other words, an impossibly strong material). -- "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 |
#45
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Towards routine, reusable space launch.
On Thursday, June 14, 2018 at 6:53:56 AM UTC+2, Fred J. McCall wrote:
I recall reading at least some analyses that said that the tensile strength required exceeded atomic forces (in other words, an impossibly strong material). According to Wikipedia the best tensile strength measured to date for multi-walled carbon nanotubes in 63GP, well short of a highly theoretical 300 GP.. No one talking (writing) about this number seems to think that 300 GP will exceed atomic forces). If I recall the last time the 'Great Space Elevator' debate stomped across the Usenet, the maximum measured tensile strength of MWCN (in laboratories) was doubling every few months. Even if that has slowed to a couple of years that means the goal set in the aforementioned PDF (i.e. that the Space Elevator is a technical challenge for the latter half of the 21st century) is at least theoretically achievable. The same PDF does also claim that a Space Elevator is theoretically possible with much weaker material (a super variant of one of the Spectra or Kevlar materials - I think) but that the sheer size of the needed cable taper makes it UNECONOMICAL, even as a multi-nation supported vanity program. If the meantime any advance in material science (i.e. the availability of much stronger composites made possible by bulk MWCN) will make traditional TSTO even more attractive. It might even make SSTO practical. Take care. Regards Frank Scrooby |
#46
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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: 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. You're the one making the assertion. What new technologies did SpaceX develop? Be specific. 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. |
#47
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Towards routine, reusable space launch.
In article ,
says... On 2018-06-13 06:46, Jeff Findley wrote: In article , Composite structures/tanks are also not new. Composites are heavily used in aerospace. For space specifically, the X-33 program designed and built cryogenic composite tanks. They failed during testing... Have cryogenic fuel/O2 tanks made solely of composites ever been sucesfully used in production rockets? No, but it was a clearly existing technology applied in a new way, so it's not a new technology. Just because I fly something into space for the first time doesn't mean it's new technology. When the two Raspberry Pi single board computers flew to ISS for the first time, they weren't new technology. The only thing different between them and the ones in my own house were the fancy milled aluminum cases/heatsinks and the "sense HAT" add-on board that you can buy off the shelf. No new tech there. https://www.raspberrypi.org/educatio...mmes/astro-pi/ https://makezine.com/2015/12/01/raspberry-pi-iss/ If BFR manages to have all composite tanks that work, doesn't that constitute innovation? Innovation in terms of engineering, but not new technology. Composites were not new to airplanes. But Boeing (with NASA funding) developped the tech and knowledge of how to produce single piece sections of fuselages, complete with the stringers (787 programme). While the material was not new, its application was. NASA and Boeing weren't the first to put composites into aircraft. As you say, they were working on larger single piece composites. It was important R&D work to expand the use of composites, but they didn't invent carbon fiber composites and they weren't the first to try to use them to build complete fuselages (Scaled Composites certainly did this earlier than Boeing). the rise of carbon fiber reinforced plastics http://www.craftechind.com/the-rise-...rced-plastics/ From above: In the 1960?s, Dr. Akio Shindo at the Agency of Industrial Science and Technology in Japan developed a carbon fiber based on polyacrylonitrile (PAN). The resulting fiber contained 55% carbon. The PAN-based conversion process quickly became the primary method for producing carbon fiber. Ninety percent of carbon fibers today are made from polyacrylonitrile (C3H3N)n or PAN a synthetic, semi-crystalline organic polymer resin. So, those Boeing fueslages, and the upcoming tanks/structure of BFR/BFS, are both based on carbon fiber composite technologies that are well over half a century old. 3D printing is a newer technology now being applied to aircraft engines and liquid fueled rocket engines. It appeared in the late 20th century. Specifically selective laser sintering (SLS) was "developed and patented" in the mid 1980s. The original patents have since expired, so the technology is now seeing quite wide spread use. https://en.wikipedia.org/wiki/Selective_laser_sintering Yes, rocket engines with 3D printed parts are relatively new, but they're built using SLS technology which was developed in the 1980s, over 30 years ago. 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. |
#48
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Towards routine, reusable space launch.
On 14-6-2018 6:53, Fred J. McCall wrote:
Alain Fournier wrote on Wed, 13 Jun 2018 19:39:10 -0400: On Jun/13/2018 at 5:35 PM, Fred J. McCall wrote : 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* theres no new technology in *anything* thats 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'. It would be possible to build a space elevator using materials available today without any major new technology. But that wouldn't be economical. Not even remotely close to being economical. New materials would be needed to build a sane space elevator, but new physics isn't needed. See for instance http://space.nss.org/media/2000-Spac...A-CP210429.pdf I recall reading at least some analyses that said that the tensile strength required exceeded atomic forces (in other words, an impossibly strong material). There was a design for interstellar traffic, using a big protection plate behind the spacepod, using a spring loaded tube to connect them,and provide a bit of distance between ship and plate. Explode nuclear bombs behind that shield. Current technology could implement it, but it would be kind of expensive. |
#49
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Towards routine, reusable space launch.
Sjouke Burry wrote on Thu, 14 Jun
2018 15:15:59 +0200: There was a design for interstellar traffic, using a big protection plate behind the spacepod, using a spring loaded tube to connect them,and provide a bit of distance between ship and plate. Explode nuclear bombs behind that shield. Current technology could implement it, but it would be kind of expensive. Notional design, not a real design. 1950's technology could implement it, as that was when the idea was originally looked at (Project Orion). This is not 'interstellar traffic' in the sense 'Doc' means, since transit times would be measured in centuries. |
#50
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Towards routine, reusable space launch.
For your reference, records indicate that
JF Mezei wrote: Is knowledge enough today that would allow micro nuclear explosions that can be focused in trhowing its mass backwards at very high speed? (aka: regular micro explosions to slowly accelerate ship) Or must one have critiocal mass of nuclear material to cause an exlosion so the smallest explosioon that can happen is HUGE ? https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) -- "Also . . . I can kill you with my brain." River Tam, Trash, Firefly |
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