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Re: It's not rocket science--we need a better way to get to space

From Sylvia Else <sylvia@not.at.this.address>
Newsgroups sci.physics
Subject Re: It's not rocket science--we need a better way to get to space
Date 2015-11-09 16:39 +1100
Message-ID <daapslFfvo9U1@mid.individual.net> (permalink)
References <gtidndfpWbFpkaPLnZ2dnUU7-UOdnZ2d@giganews.com> <da4f0200-a740-4d56-8f7a-85b1732f848f@googlegroups.com>

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On 8/11/2015 5:27 PM, nuny@bid.nes wrote:
> On Saturday, November 7, 2015 at 6:38:47 AM UTC-8, Sam Wormley
> wrote:
>> It's not rocket science--we need a better way to get to space
>>> http://phys.org/news/2015-11-rocket-sciencewe-space.html
>>
>> Rockets are a terrible way of getting to space.
>
> (nothing-new article snippet snipped)
>
> To paraphrase Churchill:
>
> "It has been said that rocketry is the worst way to get to space
> except all the others that have been tried."
>
> Not all that many "other ways" have actually been tried, but
> conceptually, they've been pretty well explored. I don't just mean in
> research labs, either.
>
> In some science fiction, actual scientists have been known to field
> thought experiments they can't propose among other scientists about
> the kinds of engineering that often descends from the sciences.
> Science fiction has depicted many other ways of getting to space;
> some feasible, some possible but infeasible (for various reasons) and
> some completely impossible.
>
> Multifunctional engines (turbojets that switch to various supersonic
> modes and or to pure rocket) are old hat in SF but are very hard to
> implement in real life, and are not likely to provide the benefits
> usually claimed- not because of unreliability, but because no
> multipurpose tool can be as efficient in any one of its functions as
> a purpose-specific tool. In other words, the Skylon system can not be
> as efficient as a standard airbreather in that phase of its operation
> as an ordinary, optimized turbojet, nor can it in its other modes
> (ignoring for the moment that hypersonic jets are not exactly mature
> enough tech to determine their efficiency or reliability). There's
> also that pesky issue of having to accelerate and decelerate empty
> fuel tanks for much of a given flight.

It's worth noting that the Sabre engine does not function as a turbo jet 
(or ramjet) at any stage of its operation. Propulsion is achieved by 
means of rockets throughout. During the air breathing phase, the rockets 
receive hydrogen from the tanks, and oxygen (and nitrogen) from the air. 
In non air-breathing mode the rockets receives all their propellants 
from the tanks.

As for having to accelerate the tanks, that reduces the payload 
fraction, but you get the tanks back intact. So you need a larger 
vehicle for a given payload, but you don't have to keep rebuilding it. 
One needs to do the sums before one can form a view about whether that's 
worthwhile.

Sylvia.

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It's not rocket science—we need a better way to get to space Sam Wormley <swormley1@gmail.com> - 2015-11-07 08:38 -0600
  Re: It's not rocket science—we need a better way to get to space Poutnik <poutnik4nntp@gmail.com> - 2015-11-07 16:01 +0100
  Re: It's not rocket science—we need a better way to get to space gilber34 <fafa@invalid.com> - 2015-11-07 09:22 -0600
    Re: It's not rocket science—we need a better way to get to space Wally W. <ww84wa@aim.com> - 2015-11-07 10:39 -0500
      Re: It's not rocket science—we need a better way to get to space Edgardo Alcantara <edgardoalcantara@carosseryrepair.org> - 2015-11-07 15:44 +0000
        Re: It's not rocket science—we need a better way to get to space Wally W. <ww84wa@aim.com> - 2015-11-07 11:00 -0500
        Re: It's not rocket science—we need a better way to get to space Fabian Russell <root@localhost.localdomain> - 2015-11-07 21:47 +0000
          Re: It's not rocket science—we need a better way to get to space Edgardo Alcantara <edgardoalcantara@carosseryrepair.org> - 2015-11-08 00:49 +0000
            Re: It's not rocket science—we need a better way to get to space Fabian Russell <root@localhost.localdomain> - 2015-11-08 01:40 +0000
              Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-08 03:27 +0000
                Re: It's not rocket science?we need a better way to get to space Fabian Russell <root@localhost.localdomain> - 2015-11-08 03:43 +0000
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-08 04:10 +0000
                Re: It's not rocket science?we need a better way to get to space Fabian Russell <root@localhost.localdomain> - 2015-11-08 04:42 +0000
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-08 06:23 +0000
                Re: It's not rocket science?we need a better way to get to space Edgardo Alcantara <edgardoalcantara@carosseryrepair.org> - 2015-11-08 16:01 +0000
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-08 17:33 +0000
                Re: It's not rocket science?we need a better way to get to space Ludwig Böhm <ludwb@widespectrum.com> - 2015-11-11 23:56 +0000
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-12 00:29 +0000
                Re: It's not rocket science?we need a better way to get to space Ludwig Böhm <ludwb@widespectrum.com> - 2015-11-12 00:38 +0000
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-12 01:11 +0000
                Re: It's not rocket science?we need a better way to get to space Ludwig Böhm <ludwb@widespectrum.com> - 2015-11-12 16:07 +0000
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-12 18:47 +0000
                Re: It's not rocket science?we need a better way to get to space kefischer <emoneyjoe@iglou.com> - 2015-11-12 16:06 -0500
                Re: It's not rocket science?we need a better way to get to space Ludwig Böhm <ludwb@widespectrum.com> - 2015-11-12 21:22 +0000
                Re: It's not rocket science?we need a better way to get to space Ludwig Böhm <ludwb@widespectrum.com> - 2015-11-12 16:08 +0000
                Re: It's not rocket science?we need a better way to get to space kefischer <emoneyjoe@iglou.com> - 2015-11-11 20:55 -0500
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-12 02:09 +0000
                Re: It's not rocket science?we need a better way to get to space kefischer <emoneyjoe@iglou.com> - 2015-11-11 23:08 -0500
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-12 04:45 +0000
                Re: It's not rocket science?we need a better way to get to space kefischer <emoneyjoe@iglou.com> - 2015-11-12 03:28 -0500
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-12 18:58 +0000
                Re: It's not rocket science?we need a better way to get to space kefischer <emoneyjoe@iglou.com> - 2015-11-12 16:11 -0500
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-12 21:43 +0000
              Re: It's not rocket science—we need a better way to get to space kefischer <emoneyjoe@iglou.com> - 2015-11-07 22:53 -0500
                Re: It's not rocket science—we need a better way to get to space Fabian Russell <root@localhost.localdomain> - 2015-11-08 04:14 +0000
                Re: It's not rocket science—we need a better way to get to space kefischer <emoneyjoe@iglou.com> - 2015-11-07 23:43 -0500
                Re: It's not rocket science—we need a better way to get to space Edgardo Alcantara <edgardoalcantara@carosseryrepair.org> - 2015-11-08 16:25 +0000
                Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-08 06:24 +0000
          Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-08 03:29 +0000
            Re: It's not rocket science?we need a better way to get to space Fabian Russell <root@localhost.localdomain> - 2015-11-08 03:40 +0000
              Re: It's not rocket science?we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-08 04:11 +0000
      Re: It's not rocket science—we need a better way to get to space Sam Wormley <swormley1@gmail.com> - 2015-11-07 09:58 -0600
        Re: It's not rocket science—we need a better way to get to space gilber34 <fafa@invalid.com> - 2015-11-07 10:01 -0600
        Re: It's not rocket science—we need a better way to get to space Wally W. <ww84wa@aim.com> - 2015-11-07 11:21 -0500
          Re: It's not rocket science—we need a better way to get to space Sam Wormley <swormley1@gmail.com> - 2015-11-07 10:23 -0600
            Re: It's not rocket science—we need a better way to get to space Wally W. <ww84wa@aim.com> - 2015-11-07 11:27 -0500
              Re: It's not rocket science—we need a better way to get to space Sam Wormley <swormley1@gmail.com> - 2015-11-07 10:29 -0600
                Re: It's not rocket science—we need a better way to get to space gilber34 <fafa@invalid.com> - 2015-11-07 10:35 -0600
                Re: It's not rocket science—we need a better way to get to space Sylvia Else <sylvia@not.at.this.address> - 2015-11-08 14:01 +1100
        Re: It's not rocket science—we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-07 18:53 +0000
          Re: It's not rocket science—we need a better way to get to space Sam Wormley <swormley1@gmail.com> - 2015-11-07 14:09 -0600
            Re: It's not rocket science—we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-07 20:22 +0000
              Re: It's not rocket science—we need a better way to get to space Sam Wormley <swormley1@gmail.com> - 2015-11-07 14:41 -0600
                Re: It's not rocket science—we need a better way to get to space jimp@specsol.spam.sux.com - 2015-11-07 21:19 +0000
            Re: It's not rocket science—we need a better way to get to space Wally W. <ww84wa@aim.com> - 2015-11-07 18:58 -0500
  Re: It's not rocket science--we need a better way to get to space "nuny@bid.nes" <Alien8752@gmail.com> - 2015-11-07 22:27 -0800
    Re: It's not rocket science--we need a better way to get to space Sylvia Else <sylvia@not.at.this.address> - 2015-11-09 16:39 +1100
      Re: It's not rocket science--we need a better way to get to space "nuny@bid.nes" <Alien8752@gmail.com> - 2015-11-09 00:41 -0800
        Re: It's not rocket science--we need a better way to get to space Sylvia Else <sylvia@not.at.this.address> - 2015-11-09 23:16 +1100

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