re: I believe it does get an L/D of 50, when forced to go hypersonic speed

Space/Science » in reply to There's no way you'll get an L/D of 50

re: I believe it does get an L/D of 50, when forced to go hypersonic speed

Success_Machine — 6/1/2004 11:06:48 AM (archived)

But only for an instant before it gets torn apart. It would be much lower at lower speed. It only has to exceed 1.0 slightly to gain altitude. The variation of total-to-static pressure ratio on Reynolds number is not linear, so although they would gain altitude at first, I don't know if they would gain sufficient altitude. Only a complicated computer program could extrapolate adequately. Hence I have no reason to expect them to succeed OR fail. I'd rather wait and see.

The whole thread (31 posts)

Airships to orbit - Tom Brosz - 5/27/2004 3:07:34 AM
- re: I don't understand why anyone would build all that hardware if they didn't do the numbers - Success_Machine - 5/31/2004 4:10:21 PM
  - There's no way you'll get an L/D of 50 - Gary - 5/31/2004 8:27:13 PM
    - re: I believe it does get an L/D of 50, when forced to go hypersonic speed - Success_Machine - 6/1/2004 11:06:48 AM
- There are exactly TWO practical ways of launching a payload into orbit. - David F Mayer - 5/30/2004 5:22:24 AM
  - Actually...... - Gary - 5/31/2004 8:31:49 PM
    - A scramjet won't get you into orbit (they flame out at Mach 10). - David F Mayer - 6/1/2004 1:03:18 AM
      - Scramjet 101 - Gary - 6/1/2004 4:35:26 AM
        
        re: Scramjet 101 - David F Mayer - 6/2/2004 12:32:24 AM
        
        Use a detonation wave analogy to understand this - Gary - 6/2/2004 3:27:55 AM
        
        You wrote: "You'll find that the detonation velocity for hydrogen-air at STP is 1968 m/sec" - David F Mayer - 6/2/2004 7:06:04 AM
        
        Yes, air for combustion is pre-heated by the bow shock - Gary - 6/2/2004 4:25:13 PM
        
        re: The only design for a scramjet that works in theory - Success_Machine - 6/2/2004 1:09:56 PM
        
        re: Controlled Flame Speed Limited to Mach 5 - Success_Machine - 6/2/2004 2:34:40 AM
- Do the numbers, Tom. Then forget it. - David F Mayer - 5/30/2004 5:09:45 AM
  - re: Do the numbers - Tom Brosz - 5/30/2004 6:22:58 AM
    - Look at the VOLUME of a balloon of ANY type required to lift a reasonable spacecraft to 30,000 meters. - David F Mayer - 5/30/2004 1:35:00 PM
  - I was only referring to using a balloon to lift a rocket here. (n/t) - DFM - 5/30/2004 5:19:50 AM
- re: Airships to orbit - Nathan Koren - 5/28/2004 3:12:12 AM
- It was me... - Adam - 5/27/2004 11:33:12 AM
- Low thrust to orbit for an airship has got to be bogus - Gary - 5/27/2004 5:52:06 AM
  - "Something is not right here." You are correct. The concept is bullshit! (n/t) - David F Mayer - 5/30/2004 5:17:07 AM
  - Color me skeptical - Larry J - 5/27/2004 6:12:43 PM
    - power sources... - Adam - 6/1/2004 11:19:27 PM
      - Still very skeptical - Larry J - 6/2/2004 2:33:32 PM
    - re: Skipping Over the Atmosphere on a Surfboard - Success_Machine - 5/27/2004 9:04:04 PM
  - re: Low thrust to orbit for an airship has got to be bogus - Adam - 5/27/2004 11:31:06 AM
    - Use VASIMR - phil - 5/27/2004 12:42:19 PM
      - For a large balloon, at any altitude, the air resistance even at low speed is comparable to its weight. I STILL say the idea is bullshit. (n/t) - David F Mayer - 5/30/2004 1:37:21 PM
- re: Airships to orbit - Raoul - 5/27/2004 5:35:39 AM
  - Visible Horizon... - Adam - 5/27/2004 11:30:18 AM

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