Not much spoken about as space travel is (7)
I believe the answer is:
orbital
'space travel is' is the definition.
I can't judge whether this defines the answer.
'not much spoken about' is the wordplay.
'not much' becomes 'bit'.
'spoken' becomes 'oral' (similar in meaning).
'about' is an insertion indicator.
'bit' going within 'oral' is 'ORBITAL'.
'as' acts as a link.
Can you help me to learn more?
(Other definitions for orbital that I've seen before include "kind of motorway" , "Rob tail (anag.)" , "going round the city" , "Going round - the M25?" , "circling a large city" .)