I don’t usually feel the need to write about the comics themselves, but I had some trouble with this one.
Initially I was going to have the robots wear space suits on the roof of the ship, not because of the need of oxygen specifically, but because they use speakers and microphones to communicate* they would need the radios (and air) inside the suits to talk in the vacuum.
But then I’d need to explain all that, and let the readers know that I know that robots don’t need to breathe, and they’re not actually cyborgs, or whatever.
So: I decided to go with the vibrations of the speakers transferring through their bare metallic feet across the hull. Remove shoes from Robot 1 and we’re good to go. Subtle, but there in case I needed it.
As it turned out, they were having too much fun blowing stuff up to talk anyway.
*Sure, they could have some wireless thing going, but I decided against it early on — from a character perspective it seemed like it would make things weird, like they were psychic all the time.