&quot;Every ship has three AI&#x27;s.  Due to the radiation and interference, all three suffer lapses in sanity.  They&#x27;re encased in lead, but the sensors are mostly wide open to radiation. Often, they &#x27;hallucinate&#x27; from from observing the outside world with faulty sensors, so they often vote as to whether or not an input is actually real.<p>&quot;A fourth AI is purposefully kept dormant.  He&#x27;s a bit single minded and his only purpose is to find a planet and touch down.  If the other three ever can&#x27;t agree or have a moment of clarity in which they realize they&#x27;ve become unstable, they deactivate and activate him.  He regularly reloads from scratch, forgetting his previous incarnations and spends a majority of time validating the coordinates his previous incarnation left for him, making course adjustments, and ensuring the humans don&#x27;t prevent him from saving them...&quot;<p>I would read that book...