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