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Comment by lbo | Hacker News Reader

Is it just me or does an inflatable space station sound terrifying. It seems like it would be very fragile if it collided with any fast-moving debris.

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The Bigelow design is actually significantly stronger than the ISS modules. You're thinking about "inflatable" wrong- they have an expandable mesh of fabric several layers thick that is extremely strong and lets them get a larger diameter module out of a smaller payload fairing. If you get hit with debris of any reasonable size, you're fucked one way or the other. The Bigelow design is easier to seal up and more robust against smaller debris.

The layered approach is how all space transport is shielded - micrometeorites puncture the 1st layer (pinhole) and turn to dust/gas, spatter against the 2nd layer harmlessly. You'll have to do 'patch duty' periodically on the outer balloon, but again its usually only pinholes to deal with, leaks are small and easily found, trivial to fix.

>If you get hit with debris of any reasonable size, you're fucked one way or the other.

I wonder if this will be included in the brochures.

I suspect (a fair proportion of) the initial crop of tourists are already aware.

The risk isn't really that high, though. It'll only become a real concern once things start to scale up. Then we'll have to clean up orbital space. The real problem is dealing with the occasional solar radiation surge. Bigelow's baseline designs were sourced from NASA, though, so I suspect they have a plan for that.

I meant it as a joke about his phrasing not about actual risk but I guess it's hard to express tone with text, at least for me :)

Ah, it might be as much a matter of my interpretation skills.

But anyway, it's still true that the real danger is radiation. I would be interested in finding out whether they intend to shield part of the station or just schedule visits around solar flares . . .

Large orbital debris is tracked, and manned spacecraft take efforts to avoid it. Natural stuff like meteoroids and whatnot are incredibly rare, combined with the fact that space is really, really, really big this makes getting hit by such things far less likely than, say, getting hit by lightning.

There is no lack of people willing to try to climb Mt Everest and this is probably a lot safer than that.

imagining that the regular ISS for example is any less permeable to space debris at high delta is silly.

Inflatable seems much more sensible to me. Especially when you consider the work in some of the self-healing plastics, etc which could seal over in the case of small, high-speed impacts.

Given the speeds we're talking about (17,000 mph [1]), regardless of what you make your space station out of, debris hitting you is likely going to go straight through.

[1]http://science.nationalgeographic.com/science/space/solar-sy...

It's not just a single layer balloon, there are layers of material and debris impact shielding as well. Look up info on TransHAB for more info on the technology.

NASA has a really nice website about orbital debris. They include lots of information and some images of stuff that's survived hits by debris.

(http://orbitaldebris.jsc.nasa.gov/)

Inflatable vs non-inflatable isn't even a particularly meaningful distinction, in space. That just tells you what the station would look like if it were sitting in a warehouse on Earth.

In space, the station is filled with air, and the outside is filled with not-air. Take all the air out of the ISS and it'll stay rigid like a tin can. Take all the air out of a Bigelow station and it'll go all floppy. But who cares? If you ever get into a situation where you don't have ~1 atm inside and 0 atm outside you're screwed anyway.

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