@Gedd your comedy of errors sounded remarkably similar to my initial runs! I can’t imagine anyone who hasn’t forgotten to load up on limpets the first time.
Limpets will definitely expire if they crash into asteroids / chunks, or have trouble getting under your ship to enter the cargo bay hatch. I find it’s best to position yourself a little further away from the debris field with plenty of space under your ship. Occasionally you’ll find a chunk of material that a limpet can’t collect, seems to be because it gets into a strange position usually too close to an asteroid. I found a piece inside an asteroid chunk once! My limpets kept suiciding into it.
I generally take about 30 limpets these days. I can get away with 1 limpet prospector per asteroid, and 2 collectors per asteroid, so for a 96 cargo hold (which I have) that’s 18 limpets minimum. Then factor in suicidal limpets and general screw ups, and about 30 seems right. You can always jettison them, they’re super cheap anyway, just set the contacts to ignore them so the limpets don’t collect them back up again.
Finding asteroids gets easier as you recognise colour patterns and the right asteroid type (there’s only one that ever has fractures in it), but sometimes you’ll find a field with precious little in there anyway, so try another.
Me, I’m trying to find Guardian relics. I discovered that you don’t need to land your ship to transfer cargo from the SRV (in fact you don’t need to be landed to board the ship either, but you do to launch the SRV). Found most of them now, just chasing Ancient Orbs! It seems they keep rolling off.
I also had my Luke Skywalker moment…