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I wonder if this is more practical nowadays. Modern “drop stitch” inflatable kayaks and paddle boards are extremely rigid, strong, light, and reliable. They also have precise 3D shapes determined by the length and position of the internal drop stitch threads. Has anyone tried using that tech to create an inflatable airplane?
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You certainly need to think about that in the design. But by rolling a 'texture' into the sheets the structure is made from, you can make sure that any hole can't 'rip' bigger, and therefore fails slowly rather than rapidly. You also need pressure regulator valves in case of fire. And you might want to make the whole thing double or triple skinned so the highest pressures can be deeper inside where they are less like…
But when do you really need a structure that has this exceptional strength on the happy path, but would still be good enough in terms of safety when pressure is lost? Unmanned aviation comes to mind, but the ratio between structural mass and battery+payload is already so low, even a zero-mass structure would not make a meaningful performance difference. It's all about the battery tech. Scaling up foil boating perhaps…
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> Except with steel as the tensile material, you can probably use pressures up around 1000 psi, making the whole structure have an amazing strength to weight ratio. Congratulations, you have created a bomb.
Wasn’t the Centaur upper stage pressurised. I remember an incident where one collapsed under load because the tank lost pressure.
"The tank of the Atlas consisted of stainless steel which was no thicker than a dime at any point. Generals, and later congressmen, worrying about what would happen if somebody dropped a wrench on such a tank were conducted to a test version of the "stainless steel balloon" that was stiffened by pressure and offered a choice of assorted mallets to see whether they could dent it. In each case the general or congressman grew tired before he had even succeeded in producing a mark that could be seen."
Willy Ley's "Rocket's, Missiles and Men in Space"
I wonder if this is more practical nowadays. Modern “drop stitch” inflatable kayaks and paddle boards are extremely rigid, strong, light, and reliable. They also have precise 3D shapes determined by the length and position of the internal drop stitch threads. Has anyone tried using that tech to create an inflatable airplane?
Discussions are not optimistic, but do invoke some related inflatable craft - https://www.reddit.com/r/WeirdWings/comments/n7a4k1/what_hap...
Earlier quoted context omitted.
> Except with steel as the tensile material, you can probably use pressures up around 1000 psi, making the whole structure have an amazing strength to weight ratio. Congratulations, you have created a bomb.
Wasn’t the Centaur upper stage pressurised. I remember an incident where one collapsed under load because the tank lost pressure.
I think this is the failure you're referring to: https://www.youtube.com/watch?v=imkdz63agHY
And here's a picture from ULA/Tony Bruno showing a Centaur tank in their factory, being supported by a rig: https://twitter.com/torybruno/status/1435553806792728579
Earlier quoted context omitted.
Wasn’t the Centaur upper stage pressurised. I remember an incident where one collapsed under load because the tank lost pressure.
Well, rockets are essentially bombs we try to make explode in a controlled manned. The "controlled" part is not always successful. Fueled rockets are treated like live bombs. No one around except for people who really need to be (like astronauts).
I'm assuming you're referring to the unnominal situations resulting in the unscheduled rapid disassembly procedures? I wonder how many people watch launches with similar intent as NASCAR races where they're just looking for the crashes or hockey games looking for the fights?
I wonder if this is more practical nowadays. Modern “drop stitch” inflatable kayaks and paddle boards are extremely rigid, strong, light, and reliable. They also have precise 3D shapes determined by the length and position of the internal drop stitch threads. Has anyone tried using that tech to create an inflatable airplane?
I think the inflatable SUPs and kayaks are as heavy as they are because of the thick layers of vinyl and nylon that prevent punctures and abrasion.
Kitesurfing kites are made of lightweight ripstop polyester, with a super-thin urethane coating, and have an inflated bladder to help hold their shape. That might be more appropriate tech for creating an airplane.
Today this would most likely have the same drawbacks as the inflatable kayaks we see for sale. Saves on space (and money?) and could be good as an entry into a hobby but at any intermediate to advanced level there are better options to choose from. With the high barrier to entry to flying I think most pilots would opt for the most reliable option from the start. I would not want to be caught in inclement weather in a…
I am surprised this was not pursued more aggressively, in fact.
I'm pretty sure it would be ridiculous and impractical, but we could use a way to solve the "it's only five blocks away but the weather's miserable" in a way that doesn't involve huge parking lots and otherwise terrible land use.
I know that there must be clothing that solves this, but donning a whole suit for what might be a 90-second trip is a lot of friction, especially when the alternative is feeling a little bit guilty about driving for a trip that could easily be biked/walked/etc.
I think there are lots of possibilities for inflatable vehicles which cannot be deflated . For example, make a flimsy structure out of thin steel foil, then pressurize it to give it far more strength than it would otherwise have. Same as the strength of a coke can. Except with steel as the tensile material, you can probably use pressures up around 1000 psi, making the whole structure have an amazing strength to weigh…
> Except with steel as the tensile material, you can probably use pressures up around 1000 psi, making the whole structure have an amazing strength to weight ratio. Congratulations, you have created a bomb.