Ouch. I've had that happen with swarmers! It's gotten to the point where I've lost so many survey ships I'm starting to make special-purpose ships designed to jump in and play rodeo clown to distract them while the survey ship gets away. (I'm also designing survey ship crew recovery shuttles to be stuck in boat bays on said ships, and when I get tractors, shuttle-tugs.) I'm also making heavily armored, really well sensored survey ships for the next generation. Stupid cosmic horrors...