I'm guessing based on all those chambers we saw in another video (or picture) that John Harrison is another Botany Bay passenger, possibly the only Botany Bay passenger that they thawed out possibly years earlier, or Harrison is a covert modern day decendent of the genetic 'superman' trying to get to the BB passengers who are still in statis in some sort of corporate research center (this is where Weller's character comes in) after the Reliant found the BB floating in space.