On Thursday, July 2, 2020 at 12:22:15 AM UTC+2, David Spain wrote:   
      
   > What you are saying about the Hindenburg: That's like saying gasoline    
   > will extinguish a match. In absence of air that is true. In fact it's    
      
   Google 'don't paint your zeppelins in rocket fuel', its bound to lead you to a   
   rather exhaustive study done by a NASA scientist (worked on the SRB dev   
   program I think).   
      
      
   > why Molotov cocktails aren't made out of plastic bottles. However, that    
   > doesn't mean I'll be dropping matches into gas cans. Let's get real, the    
   > Hindenburg fireball wasn't made up of acetate resin, even if that is    
   > what triggered it. How many acetate resin fires brought down helium    
   > balloons? I wouldn't want to ride this up through a thunderstorm, would    
      
   The acetate resin doped with alumiunum powder had already destroyed one and   
   maybe two other airships. Zeppelin (the company) was working day and night to   
   find an alternative. The company's lab where the new materials were tested   
   actually survived WWII    
   and the samples were later put in storage. Zeppelin knew there was a problem   
   (a big one) but couldn't afford to shut down its chief source of revenue, or   
   risk losing lucrative potential defense contracts with the Third Reich over a   
   'petty' safety concern.   
      
   Analysis of the very famous Hindenburg plunging to the ground in flames movie   
   revealed a few things to the aforementioned scientist.   
      
   (1) The spectacular fireball was in fact the doping catching fire and then   
   setting fire to one of the elements in the aluminium (magnesium I think) that   
   the Hindenburg was made of. Significant but less spectacular fireballs occur   
   when the heat from the    
   burning doping ignites the fuel tanks ( I can't remember if its petrol or   
   diesel).   
      
   (2) hydrogen + O2 flames are typically all but invisible and would have been   
   completely invisible on the film of the time, given how it was processed.   
   Analysis of the film through modern filters did turn up a signature of H2+O2   
   flames in the UV Spectrum.    
   But the flames are gone after the first second of the film clip, most of the   
   hydrogen is either consumed or has already escaped.    
      
   (3) the film actually shows a number of people jumping to their deaths while   
   people (at the rear of the Zeppelin) wait until the tail hits the ground   
   before trying to bail.    
      
   (4) No source of ignition external to the Hindenburg could be identified. This   
   doesn't rule out all of the exotic weather related possible causes, it just   
   points out that (then) 60 year old film technology can not be trust to capture   
   every detail.   
      
      
   > you? Why does everyone on USENET split hairs?   
       
   USENET, such as still exists (note I read and post through Google.Groups   
   because I can't get a local ISP to accept NNTP traffic), exists to SPLIT   
   HAIRS. It is the nature of the beast.   
      
   > There is a reserve parachute (partially deployed) as part of the balloon    
   > tether that allows the gondola to detach in an emergency. If there is a    
   > fireball, it would tend to burn upwards and allow the gondola to escape    
   > in the down direction. So I'm not really concerned about being    
   > incinerated in a hydrogen fire, but there are other issues (see below).    
   > Once the balloon is outside the flammable zone, passengers can unfasten    
   > seat belts.   
      
   Modern hydrogen balloons are much different beasts than the 1930s era   
   airships.    
      
   Aluminized mylar or some variation on it is used for the envelope. It is a   
   much better hydrogen trap.   
      
   And most importantly it isn't reused. A zeppelin was supposed to function like   
   a maritime ship, suitable for thousands of hours and millions of miles with   
   the very, minimum of maintenance. A modern hydrogen balloon probably isn't   
   even legal to reuse.    
      
   This company is separating the problem out, the expensive bit is the gondola   
   which is reusable. The balloon can be thrown away or recycled into party   
   balloons or returned to the manufacturer for whatever....   
      
       
   > Wonder what prevents that parachute from tangling in the event of an    
   > emergency balloon depress at altitude? As SpaceX discovered, parachute    
   > tech is tricky.   
      
   Tricky, but not impossible. How many space capsules have returned to Earth   
   without tangled chute lines. How many military cargo drops have done the same.   
   More to teh point what is the established practice for dealing with a   
   difficult 'chute . Sky divers    
   don't like doing it, but when they're in trouble they will cut it off and   
   deploy the backup. If its a rented or loaner chute the owner might be annoyed   
   but at least you get to keep your knees from being permanently relocated to   
   where your shoulder blades    
   should be.   
      
   >    
   > Also what happens if the gondola hits land rather than ocean under    
   > parachute? My achin backside.   
      
   Airbags might be an idea. Or dam good shock absorbers on the seats. For a   
   parachute landing like that shouldn't the seats be reclined? I.e.: aching back.   
       
   > I'd like some answers to these questions, but if I got good answers and    
   > the price came down to under $10K, I might consider it.   
   >    
   > Dave   
      
   Not tempted, even if it dropped below R10K (R = Rands, currently trading at R   
   17.5 to the US$). If I am going to go extreme ballooning then it needs to be   
   all the way, like the space-jumper dude did, with the same means of returning   
   to Earth (which would    
   of cause completely null-and-void any life insurance I might still have -   
   petty little South African rule, sky diving allows your insurer to cancel your   
   life insurance AND keep the money). Other than that the only other ballooning   
   I want to do is 60 feet    
   altitude fly-overs of the Serengiti. Now that is awesome. Unless you happen to   
   book your flight on the same day as an unexpected storm that forces your   
   balloon down in the middle of hungry predator country.   
      
   If I'm going to space I'm going to space the proper way, and I'm not coming   
   back.   
      
   Regards   
   Frank   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)