In need of a hit, so then pens Rocket Man? (10)

I believe the answer is:

stephenson

I'm a little stuck... Click here to teach me more about this clue!

'rocket man?' is the definition.
(George Stephenson, designer of Stephenson's Rocket)

'in need of a hit so then pens' is the wordplay.
'so then pens' can be anagrammed to 'STEPHENSON'.
Though, I'm not clear how the anagram is indicated.

Can you help me to learn more?

(Other definitions for stephenson that I've seen before include "Rocket engineer" , "Loco inventor" , "man of note" , "Train man" , "Loco engineer" .)

I've seen this clue in The Times and The Sunday Times.

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