Complex sentence: A meteor storm (which should have smashed the ship to pieces) in the unaired pilot put them off course but Smith's unplanned for 200 lbs weight in the pilot put them off course so they encountered the meteors.
Split into simpler sentences: A meteor storm (which should have smashed the ship to pieces) in the unaired pilot put them off course. In the first aired episode, Smith's unplanned for extra 200 lbs of weight put them off course so that they encountered the meteors.