A count ordered to start space program (6)
I believe the answer is:
apollo
'space program' is the definition.
(I've seen this in another clue)
'a count ordered to start' is the wordplay.
'count' becomes 'poll' (poll is a kind of count).
'to start' says to take the initial letters.
The first letter of 'ordered' is 'o'.
'a'+'poll'+'o'='APOLLO'
(Other definitions for apollo that I've seen before include "Greek god; large European butterfly" , "handsome fellow" , "London theatre" , "Greek (and Roman) god of light, poetry etc" , "Greek sungod, son of Zeus" .)