The Largest Rocket Which was Never Launched by NASA.

In November 1967, NASA launched the iconic Saturn V rocket for the first time, which was standing 110 meters tall and producing 7.6 million pounds of thrust. The Sturn V still holds the record for the largest and most powerful rocket ever launched.

But a rocket was designed the year before the Saturn V would have shattered the scale of rocket design and alter the course of rocket technology. The rocket was known as the sea dragon. This was an enormous two-stage rocket, aiming to cut costs and launch extremely heavy payloads into space.

The idea for the sea dragon came from engineer Robert Truax in the early ’60s. Truax envisioned a semi-reusable two-stage launch vehicle, capable of delivering the extreme payload to moon and mars. Simplicity, reusable, and cost-savings were the guiding principles behind the rocket design.

Sea dragon’s first stage consists of a single-engine and the 2nd stage have multiple smaller engine like Saturn V.

. instead of using complex fuel pumps, it had liquid nitrogen tanks that would pressurize the fuel tank and pus the propellant into the engine. Thinking away the complex and unreliable fuel pumps would make the engine cheaper to build. And easier to refurbish.

The sheer size of the Sea dragon, it would have been far too big to build and transport on land. The incredible amount of sound generated during liftoff would have created shockwaves strong enough to damage the launch pad and the rocket itself.

In order to overcome these issues, the rocket would need to build and launched at sea. The rocket would be built in a shipyard and towed out to the launch site. In order to orient the rocket vertically, 6 tanks near the base of the rocket would fill with water and sink the engine into the sea. Although sea-launched rocket had already been used during the second WORLD War, the technology never been tested on a large scale.

In order to begin testing the sea dragon, engineers modified a rocket from the U.S. Navy nicknamed ‘Sea Horse’. Testing begins in San Francisco Bay where engineers fired the rocket engine on a bridge above the water slowly lowered it into the water. The engineers gound that once submerged, the engine continued to fire perfectly and the sea dampened the shockwaves substantially. The success of the test opened the door for the sea dragon to become a reality.

However, like many other rocket designs, the sea dragon failed to leave the drawing board. As the 1960’s come to close, NASA’s budget was slashed as the U.S. wants to war with Vietnam. At the height of the decade, NASA’s annual budget peaked at $5.9 billion. Over the next few years, their budget was reduced by 37%. These cuts ended many of NASA’s experimental research programs along with the construction of the sea dragon.

Although Sea Dragon would have opened the door for even larger payload, NASA couldn’t justify the cost of developing the unproven technology required to make sea dragon operational.

SpaceX’s Starship rocket is the closest thing we have to the Sea Dragon concept.

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