For a while, SpaceX has dreamed of making its Falcon 9 rocket as reusable as possible, and not just the first stage. Now, though, it's having a change of heart. SpaceX has scrapped plans to make the rocket's second stage reusable. Instead, Elon Musk said, it's focused on "accelerating" development of the BFR. Musk also teased a significant design shake-up, calling it "delightfully counterintuitive" and a "radical change" compared to the previous design.