Complex sentence: Faster-than-light travel exists in this future: spacecraft operate under the "Cherenkov drive", and can travel "Sol to Capella, forty-six lightyears, in under six weeks".
Split into simpler sentences: Faster-than-light travel exists in this future. Spacecraft's operate under the "Cherenkov drive", and can travel "Sol to Capella, forty-six lightyears, in under six weeks".