Unduly fussy to snoop around orbiting vehicle (6)
I believe the answer is:
prissy
'unduly fussy' is the definition.
'prissy' can be an answer for 'fussy' (thesaurus). I am not certain of the 'unduly' bit.
'snoop around orbiting vehicle' is the wordplay.
'snoop' becomes 'pry' (I've seen this before).
'around' is an insertion indicator.
'orbiting vehicle' becomes 'iss' (I can't justify this - if you can you should give a lot more credence to this answer).
'pry' enclosing 'iss' is 'PRISSY'.
'to' is the link.
Can you help me to learn more?
(Other definitions for prissy that I've seen before include "Strait-laced" , "'Priggish, prudish (6)'" , "Prudishly fussy" , "Disliking what is rough or improper" , "Overly prim and proper" .)