ULA calls this "SMART reuse" but has not yet successfully achieved it with their Vulcan rocket. https://planetary.s3.amazonaws.com/web/assets/pictures/_2400x13

ULA calls this "SMART reuse" but has not yet successfully achieved it with their Vulcan rocket. https://planetary.s3.amazonaws.com/web/assets/pictures/_2400x1350_crop_center-center_82_line/20150413_ula-smart-system.jpg.webp https://planetary.s3.amazonaws.com/web/assets/pictures/_2400... In some ways this is simpler, but in others it is more complex since you need a way to catch the engines before they dunk in the salt water. A rocket booster that is already set up with avionics, engines, and fuel can guide and land itself without needing a precise helicopter catch etc.