Laika for one flying back to Mars, say (3)
I believe the answer is:
god
'to mars say' is the definition.
(mars is a kind of god)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for god that I've seen before include "Supreme being" , "eg Cupid" , "Deity" , "Worshipped figure" , "Anubis?" .)