God's moon mission (6)
I believe the answer is:
apollo
I believe this clue is a double definition.
'god's' is the first definition.
(Apollo is a Greek god)
'moon mission' is the second definition.
(I've seen this in another clue)
(Other definitions for apollo that I've seen before include "US space flight programme, 1961-72" , "Greek god of light, poetry, music, healing and prophecy" , "Greek god (twin brother of Artemis)" , "Greek (and Roman) god of light, poetry etc" , "Programme targeting satellite" .)