In which we learn about young woman going to space (9)
I believe the answer is:
classroom
'in which we learn' is the definition.
(place of learning)
'about young woman going to space' is the wordplay.
'about' becomes 'c' (abbreviation for 'circa').
'young woman' becomes 'lass' (lass is a kind of young woman).
'going to' says to put letters next to each other.
'space' becomes 'room' (room is a kind of space).
'c'+'lass'+'room'='CLASSROOM'
(Other definitions for classroom that I've seen before include "School space" , "Lessons are learnt here" , "Teaching chamber" , "Place for lessons" , "Part of a school" .)