Sleeper Ship Caretaker

Somewhere in space, a sleeper colony ship is on a slow course to colonize new worlds. The best and brightest had the honor of being selected to sleep away the trip and arrive at a new world ready to colonize it. You are not one of them. You are a caretaker. A backup caretaker at that. The ship must always have three crew awake to maintain the ship. If at any point there are less than three awake, a backup is woken from sleep, and will maintain the ship until they die, and are replaced. You have just been woken up.