Plan to keep orbiting craft circling throughout (6)
I believe the answer is:
passim
'throughout' is the definition.
(synonyms)
'plan to keep orbiting craft circling' is the wordplay.
I cannot really see how this works, but
'plan' could be 'pass' (pass is a kind of plan) and 'pass' is found in the answer.
The remaining letters 'im' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for passim that I've seen before include "(Lit.) throughout, everywhere" , "Throughout (a piece of writing) - frequently cited" , "At many points in book" , "(Of references) at various places through the text" .)