They could have Scott Manley do that. He does a great job with KSP, he'd do even better with real life stuff, I think. He knows what he's talking about, doesn't sutter or go "umm", and he sounds pretty hot.
He'd make an excellent NASA caster.
https://www.youtube.com/watch?v=vd83B85CUI8&list=UUxzC4EngIs...