Nanobots

Nanobots are nanometer-scale artificial organisms programmed to deploy emergency in-flight repairs to a ship's hull systems. Nanobots don't repair damage suffered by external systems as weapons, thrusters, mines, counter measure droppers, etc. Even though the ship's hull is repaired after the nanobots are activated in flight, any structural damage won't be repaired until the ship is subjected to regular repairs upon landing on a base.

Ships have a limited number of nanobots they can carry.