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Comment by m4rtink | Hacker News Reader

Caves are dark, wet, slippery and might not even contain breathable atmosphere in some cases & could get flooded in minutes, with deadly results.

Having a foldable flying drone you could use to scout for you could help a lot when exploring caves.

As for the cave scanning - I think that is mainly so they can set their design constraints & later the bot can take over, possibly including SLAM[0]. There are already designs like that that have been tested in unexplored flooded caves[1].

[0] https://en.wikipedia.org/wiki/Simultaneous_localization_and_... [1] https://en.wikipedia.org/wiki/DEPTHX

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> Having a foldable flying drone you could use to scout for you could help a lot when exploring caves.

I agree with that. But is this the right form for it? Airships are bulky. Caves are obstructed. A smaller flying drone, like some form of a multicopter would be my choice if I want to maximise the chances that it fits the cave.

> Thanks to their long-flight endurance, they are suited for long-term missions.

How long can your drone stay in the air?

They cap out at several hours for gas powered drones or ~1h of flying time for batteries.

But it’s unlikely for you to actually need endurance because you’re not getting signal that far through a cave without repeaters or a long cable. A bigger deal is being able to go underwater or fit through tiny openings.

Running a gas powered drone in a low oxygen environment sounds like a great way to get the next cavers killed by asphyxiation

Most gas powered drones don’t actually use much fuel and thus their oxygen use is limited. At the extreme end a 20 pound drone might use the same oxygen per minute as ~5 people and you’re not going to stay in the same place for that long vs people going through rough terrain. If anything adding gas sensors would more than make up for such issues.

Personally I’d be more concerned with explosive gas mixtures, but that’s not an issue in most cave systems.

> But it’s unlikely for you to actually need endurance because you’re not getting signal that far through a cave without repeaters or a long cable.

I mean you could let it roam on it's own and report back no? But even if you had to be in the same area as it, it then lets you go for even longer. Like some people sleep in these caves and bag in/out a bunch of supplies so needing to carry less batteries would be nice I assume.

> A bigger deal is being able to go underwater or fit through tiny openings.

That's in the abstract as well: "Our design strengthens the robot while granting the ability to access narrow spaces by folding the structure - up to a volume expansion ratio of 19.8."

Talked to some local cave explorers once (Czech Republic has huge karst cave systems) and they mentioned they often hang from a rope on wet cave walls with power tools and rubber boots when making new parts of caves accessible, so they can press further to new parts.

A floating lightning drone could be useful for that. :)

You could combine this with inflatable light technology & the gas bag itself could be a source of illumination.

Particularly the multicopter is mass produced, cheap, mature and easy to buy and use.

Many caves are not particularly wet , slippery, or prone to flooding. Only a few have issues with a lack of airflow. I understand the interest in robotic exploration for some specifically risky caves, but I don't like this generalization that implies all caves are too dangerous for humans to enter.

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