Factory containing last piece of satellite for Mars, perhaps (6)
I believe the answer is:
planet
'mars perhaps' is the definition.
(mars is a kind of planet)
'factory containing last piece of satellite' is the wordplay.
'factory' becomes 'plant' (I've seen this before).
'containing' indicates putting letters inside.
'last piece of' says to take the final letters.
The final letter of 'satellite' is 'e'.
'plant' going around 'e' is 'PLANET'.
'for' is the link.
(Other definitions for planet that I've seen before include "Heavenly (or earthly!) body" , "Eg, Mars or Pluto" , "Earth, for instance" , "Orbiting heavenly body" , "massive revolver" .)