[Lex]

Space navigation is obviously 3D, and with only four NWSE words to refer to the principal axes are not enough for navigation or storyboarding. I guess little would object to calling the fifth direction "Zenith", but still we kinda need an agreement on the sixth, which is the other side of Zenith. Wikipedia pointed out "Nadir" is a word to use, however its abbr. of N is not a good choice... I suggest calling this direction "Antipole", with an intuitive contrast between Z and A directions. What are your thoughts all?