Hour in space is unable to delight (7)
I believe the answer is:
enchant
'delight' is the definition.
(enchanting is a kind of delighting)
'hour in space is unable to' is the wordplay.
'hour' becomes 'h'.
'in' indicates putting letters inside.
'space' becomes 'en'.
'is unable to' becomes 'cant' (can't).
'en'+'cant'='encant'
'h' going within 'encant' is 'ENCHANT'.
(Other definitions for enchant that I've seen before include "Delight, cast spell over" , "Delight or bewitch" , "Appeal" , "Delight, charm" , "transport" .)