Early rounds in contest run round one section of shuttle (4,6)
I believe the answer is:
heat shield
'early rounds in contest run' is the definition.
I can't judge whether this definition defines the answer.
'round one section of shuttle' is the wordplay.
'round' becomes 'heat' (stage of a competition).
'one section of shuttle' becomes 'shield' (I can't justify this - if you can you should give a lot more credence to this answer).
'heat'+'shield'='HEAT SHIELD'
Can you help me to learn more?
(Another definition for heat shield that I've seen is " Spacecraft's protection from high temperatures".)