Python Tanks - Maze with no Walls

It is the same spiral maze, but with most of the walls gone!
How could we decide when the tank needs to turn?
Look, there is a star at each corner - can we use this fact?

Prev
#it is the same code, #but now it needs to be changed more... right() while look_below() != 'star': while look_ahead() != 'wall': forward()