Head to asteroid by way of spinning extraterrestrial pilot (6)
I believe the answer is:
aviate
'pilot' is the definition.
(I know that pilot can be written as aviate)
'head to asteroid by way of spinning extraterrestrial' is the wordplay.
'head to' indicates taking the first letters.
'by way of' becomes 'via' (via means by way of or by means of).
'spinning' says the letters should be written in reverse.
'extraterrestrial' becomes 'et' (I've seen this in other clues).
The initial letter of 'asteroid' is 'a'.
'et' back-to-front is 'te'.
'a'+'via'+'te'='AVIATE'
(Other definitions for aviate that I've seen before include "Ride the Zephyr, say" , "Handle jumbo, maybe" , "Fly" , "Pilot a plane" .)