For those who are unaware: A couple billionaires, a pilot, and one of the billionaires’ son are currently stuck inside an extremely tiny sub a couple thousand meters under the sea (inside of the sub with the guys above).
They were supposed to dive down to the titanic, but lost connection about halfway down. They’ve been missing for the past 48 hours, and have 2 days until the oxygen in the sub runs out. Do you think they’ll make it?
I wonder…is that only because we use probes? Or is it something to do with atmospheric pressure? Like I’m assuming water is heavier than space so even if you had a space suit on underwater you’d still get crushed or eaten by some big ass squid.
I’d love if a scientist could weigh in on this.
My layperson understanding is that with space you only have to have something robust enough to keep the atmospheric pressure in (as well as other considerations of course) which allows for less robust materials. For deep sea exploration you need something robust enough to keep the water pressure out.
For additional info: 10 metres of water depth is approximately equivalent to 1 atmosphere’s worth of pressure (ATM) - so 50 metres is 5ATM and so on and so forth. So theoretically a submarine would have to combat hundreds of ATMs of pressure, whereas a space craft only has to combat at most a couple of ATM.
In the ISS a minor hole can be patched pretty easily and quickly as it’s a slow leak of air out, however if a leak occurs in a submarine the results can be explosive and deadly.
Thank you, yes this is what I had in my head, I appreciate you wording it properly, with examples!
To add a little: when a thing fails in compression (submarine), it’s usually unpredictable and catastrophic. When it fails in tension (spaceship), it starts slow and fails in a predictable way.
Tension is also much easier to calculate when you’re designing structures. Engineers will often go out of their way to make sure that tensile failure is the controlling failure mode, just to make sure that we don’t have to fuck with compression.
So, I’m not a scientist, but I’ve watched plenty of space and ocean documentaries because it’s interesting to think about, so I’m pretty qualified, right? So, space is actually the opposite of heavy. It’s a vacuum, so the vessels designed to operate there have to deal with holding pressure IN, instead of out. Also, there’s no big ass squid in space to eat you, lmao.
Yes you are qualified, cause you summed it up pretty good! Summary: ocean is sketchy af!
even if you get a hole in your space suit you’ll live for a minute or so before freezing/dying of lack of oxygen. Get a pin hole in a sub down by the titanic and it will basically instantly implode killing you before you even knew something happened. space is far easier other than getting there and the radiation you need to protect against long term.
I never thought about it this way, but I think you’re right. I’m an engineer, and we go out of our way to avoid designing things that need to resist compression. Tension is much easier to calculate and things fail in a more consistent and predictable way. When things fail from compression, it’s usually unpredictable and catastrophic.
You compensate for that by making it as symmetrical as possible to balance forces and increasing safety factors to stay very far away from a runaway failure situation.
The designers of this sub were crowing about some kind of “active monitoring” system to see if the hull was in danger in real time. My take on that is they cheaped out on construction and slapped some strain gages (detect micro-bending or stretching) on it to make sure they didn’t get too close to failure from going too deep. But if there was a material or construction failure, it would just pop like a bubble before the strain gages could tell them anything was wrong.
But anyways, a spaceship is mostly under tension, but a submarine is under compression. So I think you pretty much nailed it there.