Well...no. Its flying along the axis of thrust, its just the axis of thrust is at right angles to what you might expect. The ion drive only produces a few hundredths of a G of thrust, but that's fine for deep space, the engine fires continuously for months. The ship is also spinning about the thrust axis, like a propeller, in order to simulate gravity for the crew, who occupy the hab module, nearest to us. The ship's reactor, which provides power for the electric ion drive is at the far end of the rotating boom, to provide a counterbalance for the hab, and to keep the radiation hazard as far away as possible from the crew.