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Comment by suifbwish | Hacker News Reader

Would spacex be liable if one of their satellites hits your car or house?

Small satellites like Starlink burn up in athmosphere. But if you're curious about liability laws for falling satellites, here's the relevant UN convention: http://www.unoosa.org/pdf/gares/ARES_26_2777E.pdf

That convention makes states (i.e. national governments) liable, but doesn't by itself make SpaceX liable. I assume SpaceX would be liable under ordinary tort law in the U.S., irrespective of the convention. At least for claims against U.S. nationals, the convention is probably mostly irrelevant; it's purpose is to act as a backstop in case compensation can't be found using normal legal procedures--e.g. courts won't otherwise hear a claim (AFAIU, the U.S. is relatively liberal in permitting foreign entities to sue in domestic courts for all manner of situations, and to do so on equal footing), or the entity is unable to pay compensation, in which cases the state signatory effectively acts as a guarantor for all the entities within its jurisdiction.

> That convention makes states (i.e. national governments) liable, but doesn't by itself make SpaceX liable.

The US is liable for any damage from space SpaceX causes in a different country. If it hits a house in the US, that's a completely different question.

If there’s so little atmosphere that a Starlink doesn’t burn up before it hits your car, the ICE engine would have trouble running anyway.

How modified would a Tesla Cybertruck need to be to run on the moon?

If I had to guess, probably quite a bit. I doubt the battery cells or the electronics would hold up under hard vacuum.

I recall a story posted here that if you put an iPhone in helium it will break the MEMS components inside of it and it will fail to boot, and that's still at 1 atmosphere.

The battery is already sealed, and 1 atmosphere isn't a lot of pressure to contain. It might even be able to be pressurized to quite a bit less. Regarding the electronics, engineering-wise that's a solved problem. And it would only need the drivetrain and charging electronics.

I suppose that a wider track would be useful in 1/3 G, but that is a mod that off-roaders have been doing at home for decades. Ditto ride height and wheel size.

I would not be surprised to see a Cybertruck offloading from a Starship someday, maybe even on a private mission after Artemis finishes.

Yes. But they're designed to burn up on entry. I think it's been mentioned on HN that the delay in their laser link network was due to the need to redesign the laser component to ensure it would break up.

When people say something will "burn up on reentry", a phrase that I've heard almost all of my life but never really given much thought too, how burnt are we talking? Surely it doesn't just completely atomize?

I’d love to know more about this too.

I don't know specifically but as a layman I'd imagine the satellite breaking up into smaller and smaller pieces due to the rapid heating and the "wind resistance"(?) from making contact with the atmosphere at high speeds.

I'd also imagine that at some point in this breaking-up-process the pieces are small enough to sublimate from the extreme heat, i.e. "burning up".

Do you remember, back when SpaceX used aluminum grid fins, when you'd see a Stage 1 re-entering, and you could watch the grid fins erode away in realtime video?

Think of that, but for, well, everything.

You know how racecars spectacularly fly to pieces when they crash? That is by design - as it rapidly sheds energy. Same thing applies to things that "burn up on reentry", so long as you prevent the thing from coming down as one solid lump of glowing hot metal - the surface area to mass ratio renders the fragments harmless.

I wonder if anyone has ever tested the whole thing about field mice surviving a drop from any height due to their low terminal velocity... those bat bombs in WWII don't count.

Here's a video of a satellite (a very large one) reentering: https://www.youtube.com/watch?v=OhBw5yaR_SU

And here's a timelapse in a hypersonic plasma test chamber: https://www.youtube.com/watch?v=q_AcG4ZQItg

(Keep in mind the pieces that come off are still going to keep being heated even after they seperate.)

It largely does atomize yes, depending on the material. Which is why they're designed out of materials that will do this.

Yeah, I mean to be specific your homeowners' insurance would pay you directly for "falling debris", but then they would go sue SpaceX to get their money back.

This reminds me of an episode of Jim Henson's TV series Dinosaurs where a space rock hits the Sinclairs' house, and the insurance refuses to pay out. Because they had "meteor" insurance, so their house would only be covered if it was floating in the upper atmosphere at the time of the strike. Instead, the insurance said their house was hit with a meteorite (a meteor that reached the ground), which wasn't covered under their policy.

They should have argued that it hadn't yet hit the ground when it hit their house.

It wasn't a meteorite when it hit the house, only when it hit Earth. I know, hit me with the downvotes.

I think their house was made of earth (rock).

Probably? But I imagine that won't/can't happen because the satellite is likely designed to burn upon reentry. It would seriously surprise me if no regulatory body thought of this before they sent thousands into LEO.

If you can build your house, or drive your car, at that altitude I rather think you'd be the one being liable! :D

(based on the fact these satellites are designed to burn up completely upon re-entry into Earth's atmosphere and so no 'chunks' reach the surface)

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