__ projection (6)
'projection' is the definition.
(I know that spur is a type of projection)
This is all the clue.
(Other definitions for spur that I've seen before include "outcrop" , "Rider's heel wheel" , "Incite to action" , "Sharp pointed projection" , "Strong incentive" .)
(Other definitions for astral that I've seen before include "Universal" , "Related to the stars" , "Resembling the stars - of the spirit world" , "Pertaining to the stars" , "19 [STELLAR]" .)