Peter Duncan lay strapped, drugged and supine on one of the eighty narrow bucket-couches on the passenger deck and was miserably, continuously sick. It was not a nice steady nausea that a man could adjust to. Nor even a rhythmic vertigo like one suffered from an ocean liner wallowing in ground swells. It was a shifting, sliding instability in three dimensions, as the Mars-bound vessel responded to automatic radar controls. The concept of interplanetary space being empty was long since an explode