The Sea Dragon was the largest rocket ever conceived. Created in the 1960s by Aerojet engineer Robert Truax, Sea Dragon was an enormous ocean-launched rocket designed to haul up to 550 tons into low Earth orbit—far beyond the capacity of any rocket ever built. The plan relied on low-cost shipyard construction, sea launch by buoyancy, and a simple ignition system to dramatically cut launch costs. Although it was never constructed, Sea Dragon remains one of the most audacious concepts in spaceflight history. Developed under Aerojet, it stands as a powerful example of how visionary engineering ideas can push the boundaries of what humanity believes is possible.(Historic Vids)