 Why is David Corbin on the ship in the first place?
CAPTAIN CHAOS By D. ALLEN MORRISSEY Science equipped David Corbin with borrowed time; sent him winging out in a state of suspension to future centuries ... to a dark blue world whose only defense was to seal tight the prying minds of foolish interlopers. "Your name is David Corbin. "Your name is David Corbin. "Your name is David Corbin." After the first shock of looking out, I accepted the fact that I was in a space ship, yet I couldn't read the maps that were fastened to a table, nor understand the function or design of the compact machinery. "Your name is David Corbin. Everything lay in readiness, fastened down star charts, instruments, glittering equipment. The ports on the side were shielded and I stared out at static energy, hung motionless in a world of searing light. What speeds and perhaps, what distance? They stood for anything I might guess, and something kept pricking my mind, telling me I had no time to guess. I went from the nose to the last bulkhead in a frenzy of floating motion, looking behind each door until I went as far as I could. They both ended in the lead shield that was set where the swell of the curve was biggest. It meant the engine or engines took up half the ship, cut off from the forward half by the instrument studded shield. I had literally been reborn in this room, equipped with half ideas, and no point to start from, no premise to seek.
 He has to direct his crew to an area with potentially habitable planets.
 He has to direct his crew to an area with potentially large amounts of natural resources.  He has to direct his crew to an area with potentially habitable planets.  He's a doctor who has to tend to the other crew members who were medically sedated.  He has to direct his crew home to Earth on the tail end of their intergalactic voyage.