Roll

The Roll axis is one of the three principal axes in which an aircraft or spacecraft can change orientation. A shift in the roll axis will cause a craft to rotate about its principal axis.
Larger aircraft/spacecraft, especially very wide vehicles, will have very little Roll control without the addition of control parts.
Placing RCS thruster blocks or movable control surfaces on the sides will increase a crafts Roll ability. Engines with thrust vectoring will not help control Roll.