How are space missiles actually built

Sea Dragon: The Biggest Missile That Never Flew

There is a new world run into space! The US wants a base on the moon - as do China and the EU. That takes gigantic missiles. As early as the 1960s, a researcher designed a mega-rocket that was supposed to transport entire habitats and space stations with one launch. But it never took off into space.

From Michael Förtsch

On May 30, 2020, the United States of America brought people from their own soil and at the tip of a US rocket into space for the first time in almost a decade. Since the end of the space shuttle program in 2011, NASA has relied on flight opportunities in the Russian Soyuz capsules. The successful start is, as NASA itself writes, the beginning of "a new era in manned space travel", which is said to be characterized by daring missions such as the Artemis lunar program, a space station in orbit of the moon and a base on the moon. To this end, NASA is cooperating with companies such as SpaceX and Boeing. But she's also working on her own hardware that should make the gigantic plans possible.

In particular, NASA engineers have been working on the Space Launch System, a new heavy-lift rocket, for almost nine years. In its largest expansion stage, it will be over 111 meters high and be able to lift up to 130 tons into orbit. If it is finished in time, it would be the most powerful missile in action. At least until the Starship and SpaceX's Super Heavy rocket stage make their debut, which are supposed to weigh up to 150 tons. And in retrospect, the Saturn V moon rocket is still the most powerful and largest rocket ever built. However, NASA had once considered designing a rocket that would have overshadowed the SLS, the Starship, the Saturn V and all other currently planned heavy-duty rockets: the Sea Dragon, which was launched by one during the space race with the Soviet Union Missile pioneer was planned.

Why so big

From the mid-1950s onwards, one shock followed another for the United States. In May 1957, the Soviet Union launched the R-7, the first intercontinental missile. In October of the same year, a rocket of the same type was launched into space. On board: no warhead, but something with symbolic power. The rocket launched the first artificial satellite, the Sputnik 1, its Peep peep was received worldwide. It was proof that the Soviet missiles can now reach any point on earth and space. But above all, it was a warning sign for the USA that the United States was in danger of losing its technical superiority. The result: the founding of NASA, which then launched the first US satellite into space and launched Project Mercury in order to transport a person into Earth orbit off the Soviet Union.

In April 1961, however, the moment came that shook the United States deeply. Instead of an American, the cosmonaut Yuri Gagarin was the first person to reach space in the Vostok 1 space capsule and circled the earth in just over 100 minutes before landing safely again. It was therefore clear that the USA not only had to follow suit in space, as it did with Sputnik, but also had to come up trumps. Be it by permanently bringing people into space with a station or by transporting a person to the moon, as President John F. Kennedy finally announced to the world in his “We choose to go to the moon” address on September 12, 1962 . But for that, that was certain, strong missiles were needed.

A team led by rocket builder Wernher von Braun was already working on one of these, namely a further developed variant of the Saturn C rocket, which would later become the Saturn V. One missile builder believed, however, that such missiles would not be the right choice - especially with a view to the future. The idea of ​​this time: Thousands of people would soon be working in space, space stations would orbit the earth, raw materials would be harvested on the moon and bases would be set up on Mars. That rocket builder was Robert Truax - and it wasn't just anyone. He was a former marine soldier who was working for the renowned engine manufacturer Aerojet General at the time. Truax had already built small missiles as a child, later became involved in the American Rocket Society and then collaborated on research on the PGM-17 Thor, the first ballistic missile of the US Air Force. He was thus one of the pioneers in US missile technology.

Become a member of 1E9 - for as little as 3 euros a month!

As a member, you support independent, future-oriented tech journalism that is created for and with a community of idealists, founders, nerds, scientists and creatives. You also get full access to the 1E9 community, exclusive newsletters and can be part of 1E9 events.

Join Now!

Truax was convinced that rockets like the later Saturn V are technical masterpieces, but their complexity makes them error-prone, expensive and inefficient. He also found them too small and weak to really advance space travel. Above all, however, they could not be reused: a total waste! His counter-proposal was the Sea Dragon rocket, which, as the study was paraphrased, “would take better account of the space transport economy”.

With one launch, it should lift 500 to 550 tons of payload into space - around three times what the Space X is planning for its largest rocket. In addition, the Sea Dragon should be designed simply enough to avoid failures like the complex NASA rockets, which like to explode in the prototype stage for reasons that are initially unclear. And since parts of the rocket should be reusable, it should be useful for many decades. Above all, however, it should give the USA a great advantage in racing into space.

Simply mega!

The rocket, which Robert Truax is said to have designed in just one year, was to be a real giant. It should measure between 150 to 168 meters in height - and thus almost half as high as the television tower in Berlin - and around 23 meters in diameter. As a result, there should be enough space in it to hold gigantic amounts of cargo - be it supplies for space stations and lunar bases. Or even an entire space station or spaceship big enough for a trip to Mars. The rocket was to be built from eight millimeter thick steel walls and aluminum. The Sea Dragon was supposed to be propelled upwards by two rocket stages, which were designed to be simple and therefore predictable.

What all of this has to do with Evel Knievel

After Robert Truax ’dream for the Sea Dragon died at NASA, he started his own rocket company. One of his customers was the stunt hero Evel Knievel, who was known for his daring motorcycle stunts. Truax built a rocket with a seat for him, with which Evel Knievel wanted to jump over the Snake River Canyon. The missile worked - but the parachute unfolded too early and pulled Knievel into the canyon. Nevertheless, the spectacle was a media success.

Knievel asked Truax what else was possible. The rocket manufacturer suggested that Knievel be the first private person to be launched into space. He was enthusiastic and financed the research work for the rocket X-3 Volksrocket, which should make this possible. Soon afterwards, Knievel got caught up in an expensive legal battle. So Truax looked for other financiers and potential astronauts - and received thousands of letters from would-be spacemen. But he couldn't find any financiers, which is why Truax ultimately turned around and accepted an order to develop light missiles for the military.

Former companions are convinced that Truax could actually have fired the stunt hero into space.

The tank of the first stage should be filled with the long-established RP-1 - quasi-distilled aircraft kerosene - and liquid oxygen. The second stage tank should be filled with liquid hydrogen and oxygen. Unlike the rocket builders at NASA, Robert Truax wanted to do without expensive and error-prone turbo pumps. Instead, a chamber with liquid nitrogen should be opened at startup. The nitrogen would expand and the sheer pressure would force the fuels into the engines - each stage only had one, but which was supposed to be huge.

The design proposed by Truax was as simple as possible - and is therefore today as a big dumb booster known. Building, maintaining and testing such a drive is neither expensive nor particularly difficult for experienced companies. Due to the massive tanks and the gigantic nozzles, the first stage of the Sea Dragon should generate a thrust of 360 million Newtons and the second of 60 million Newtons. For comparison: The Falcon 9, which brought the astronauts into space at the end of May, only developed seven million Newtons of thrust. Exactly this uncompromisingly gigantic design and the irrepressible thrust would have brought some problems with it.

From the water to the air

Robert Truax was a visionary, but also a pragmatist. He was under no illusions about the disadvantages his Sea Dragon would have. Among other things, it would have been so big that it would have been a logistical nightmare to have the huge shell parts, nozzles and motors built by the specialist manufacturers at the time and transported over hundreds of kilometers in order to then assemble them at the launch site. And with every rocket, every time anew. In addition, there wasn't even a launch site that would have been suitable for the Sea Dragon.

Just the thrust, the heat, the pressure waves and the flames of the first rocket stage would have reduced the launch pads to rubble, as they did at Cape Canaveral Air Force Station. In addition, the ignition of the first stage would have triggered a bang that would have been 165 decibels eight kilometers away - louder than a tank gun and above the limit of what most sound pressure meters can detect. As a result, the launch in nearby settlements would have caused clinking windows and hearing damage. Truax's solution: "The rocket should be launched directly from the water while propelling vertically," says the 1963 project study.

In fact, the rocket builder intended to transport the entire rocket out to sea - that explains the name of the rocket. That is why Truax came to the conclusion that the rocket could be manufactured in the dry dock of a shipyard. And according to inquiries from Aerojet from this time, the "answers [from several shipyard operators] would have been uniformly positive in terms of feasibility". Because the tanks would have been little different from the hull of a ship or submarine. When the rocket is ready, it could have been towed into a stretch of coast off Cape Canaveral, for example. Or out to sea with an aircraft carrier.

There the Sea Dragon should be immersed in the water. A ballast tank under the first stage engine should be filled with water to keep it level. Then it would have been refueled and slowly sunk deeper into the water. Depending on the load, a third of the rocket or even its tip would have looked out of the ocean. According to Truax, this water-start solution would not only have been a stopgap, it would also have had remarkable advantages. For example, the pressure of the water works as a natural side stabilizer for the rocket. The launch would supposedly have been more problem-free - and certainly far more spectacular - than that of other missiles.

The first rocket stage would have lifted the Sea Dragon out of the water, which was supposed to absorb the eerie pressure and sound of the ignition. The first stage would have burned just over 80 seconds and transported the rocket on a burst of fire around one and a half kilometers long at an altitude of around 40 kilometers. Four smaller control nozzles would have brought the colossus onto the right track when it emerged from the water. Then the first step would have been thrown off. The second stage would then have burned for 260 seconds and carried the rocket up to an altitude of 230 kilometers. Robert Truax and his colleagues believed that at least the first rocket stage - and if it were further developed, the second stage too - could be reusable.

Corresponding reinforcements for a fall would hardly have mattered with the mass of the rocket. There have already been ideas with a kind of supersonic air bag to slow down the fall towards the water, to minimize damage from the impact and to avoid sinking to the seabed. Then a step could easily have been salvaged from a ship. Instead of producing new rocket stages, the previous ones could have simply been refurbished, which would not have been particularly expensive due to the simple design. Not much different from the SpaceX ’Flacon 9 rocket stages, which, however, can also land by themselves.

The race was over too early

As absurd as the idea for the Sea Dragon may seem, it met with some interest at NASA, even though the Saturn V was just being manufactured. Especially with those responsible for the so-called Future Projects. Those were the ones who worked at the US space agency on what might come after the moon landing. Just dreams of space stations, lunar and Mars bases - and for them the Sea Dragon seemed perfect, almost too perfect. NASA therefore had the proposals, concepts and calculations for the Sea Dragon checked by the former Pioneer 1 builder TRW Inc., who also surprisingly came to the conclusion: Yes, the Sea Dragon is feasible and, in principle, a plausible idea.

For a while, it almost looked as if the gigantic rocket was actually going to be built. The Aerojet company even considered buying a stretch of coast near Vandenberg Air Force Base in order to launch the Sea Dragon there in the future. But then the landing on the moon succeeded - and the atmosphere at NASA changed. The United States seemed to have won the space race. And instead of taking the next big step, that to Mars or to a permanent presence on the moon, the plans for the future in space were slashed - and with it the budget of NASA and its major future projects.

There was no justification and no need to build a mega-missile like the Sea Dragon. Even for the Saturn V there was hardly any use after the moon landing. There just wasn't a lot of weight left to heave into space. At least not in history as it was in reality. Because the Sea Dragon lives on in science fiction. In the Apple TV Plus series For All Mankind history took a different course. Not the USA, but the Soviet Union landed the first man on the moon, whereupon the space race continues and gets hotter. Bases are being established on the moon. And at the end of the first season, a Sea Dragon is fired into space. On board a huge extension for the first US lunar station Jamestown.

Teaser image: Apple