This is the largest rocket to never fly. The Sea Dragon was a 1980s concept for a NASA rocket that makes the Saturn V and even the modern mighty starship look like a toothpick. This behemoth could carry 550 metric tons pretty much wherever it wanted to. Sea Dragon was so powerful that it needed to be carried out into the open water and launched at sea just so it wouldn't level everything around it, and to absorb its own shock waves that would otherwise destroy it. Sea Dragon was designed to be cheaply manufactured in a shipyard, but NASA's dwindling budget and the cancellation of the Apollo program pretty much slayed the dragon and any hope of making it. If it was even technically feasible, but it makes a cool concept though.