In the history of space, one rocket
stands out as an icon not only at the
space race but also as the mighty power
is symbolized, that one rocket which is
still the tallest, heaviest and most
powerful ever built was the Saturn V
and was designed to take men to the moon
and later launched to the first American
space station Skylab but if things have
been a little bit different back in the
1960s we might have had a different
rocket to hang on the bedroom walls of
the space fans of the 70s and 80s. In the
early 1960s a rocket was designed that
made the Saturn V looks small by
comparison. This was called the sea
dragon a super heavy lift rocket that
would have been ten times more powerful
with 80 million pounds of thrust
compared to the Saturns 7.8 million and
that was from just one massive engine. It
was designed to lift a payload of 1,100,000 lbs
into
orbit compared to the
310,000 lbs of a Saturn V. This
meant but it could have lifted an entire
space station into low-earth orbit in
one mission. The rocket bell of this
single engine would be so large at 75
feet in diameter that you could fit the
entire first stage of a Saturn V with
all five of it's F-1 engines inside with
room to spare. So what happened to the
Sea Dragon a why didn't it get built. At
the time of a design in 1962 it was
thought by the 1970s, 80s and beyond
thousands of people would be working in
space and on the moon even on Mars and
as such rockets with huge lifting
capabilities would have been in great
demand because they would have
dramatically lower the cost of getting
materials into space. The Sea Dragon was
designed by Robert Truax, a US Navy
Captain and rocket engineer. He was one
of the pioneers of American rocketry and
worked on the Thor and Polaris missiles
amongst others.
His team debriefed the German rocket
engineers at the end of World War II
including Verner von Braun who went on
to design the Saturn V. Truax believed
that it was complexity that drove up the
cost of rockets and not their size. His
designs for the Sea Dragon made it very
simple yet very large. The Sea Dragon
would have been 75 feet in diameter and
500 feet tall, half the height of the
Chrysler Building. This type of low-cost
super heavy rocket is now known as a big
dumb booster due to its simplistic
design. Instead of having very
complicated turbo pump driven engines
like the Saturn's, his were the simplest
possible design for a rocket engine. In
place of having powerful fuel pumps to
push huge amounts of rocket fuel and
oxidizer into the engine, he proposed a
pressure fed system with a separate
liquid nitrogen tank to pressurize the
fuel tanks. This would push the fuel into
the massive combustion chamber. His
engines were literally not much more
than the valve to turn on the fuel and
the huge engine bell. This would make
them not only much cheaper to
manufacture but more reliable and much
easier to refurbish and reuse unlike the
f-1 engines of a Saturn which were left
to crash into the sea and be discarded.
The rocket would be of a two-stage
design the first stage would lift it to
a height of 130,000 feet before it
separated and then fell back into the
sea using drag bags to slow its impact
with the water, where it would then be
recovered for reuse. Although the design
was much less efficient than a Saturn,
the overall increase in size made up
that shortfall so in theory it would be
much cheaper per pound of payload
compared to smaller rocket systems even
ones the size of a Saturn. However there
are problems in making such a huge
rocket firstly just transporting the parts
let alone the fully assembled version.
This together with the 80 million pounds
of thrust meant but it could not be launched from land.
This amount of thrust would have
destroyed any existing launch pad. It's
estimated that the noise level at
takeoff would have been around 165
decibels, five miles away or the
equivalent of standing next to a 5,000
horsepower top fuel dragster at full
throttle. Then there was the exhaust
plume this would have been up to one
mile long. For these reasons the Sea
Dragon would have been launched at sea, hence the name.
Not from a floating platform
but from beneath the water. Now this is
not as mad as it seems and there have
been examples of sea launch rockets
before and after. In 2002 a low-cost sea
launch rocket delivery system called the
Aquarius with a very similar design to
the Sea Dragon but much smaller was
proposed to deliver consumables in to
low-earth orbit for supplying things
like the space station but failed to
get selected. Then there was the US Navy
which also did research into floating
launch rockets and found that the
take-off or smoother and less stressful
on the rocket than that of a normal
land-based takeoff. And if you're
wondering why the water doesn't put out
the flames it's because the rocket has
its own liquid oxygen supply just like
the Rockets that work in space where
there is no air and the thrust just
blows the water out of the engine bell.
In fact the sea makes an excellent
launch platform as it's indestructible
it requires very little in the way of
support systems which makes it very
cheap, it also provides excellent shock
and noise oppression and even allowing
for a slight swell, the density of water
helps guide to rock it up in the initial
moments of lift off till it the exits of
water. As part of a low-cost build and
the size of Sea Dragon, it would have
been built in a shipyard a bit like a
submarine from commonly used materials
including aluminium, sheet nickel steel
and stainless steel for the engine Bell.
It would have then been floated into
position and fueled allowing it to sink
so that just the top was sticking out of
water and it would have been supported
by flotation tanks under
rocket. one idea was to use a nuclear
aircraft carrier to provide the power to
electrolyze the sea water to make the
hydrogen and oxygen rocket fuel, although
the first stage would have been powered
by RP1 or Kerosene and oxygen, the second
stage was powered by hydrogen and oxygen.
Although smaller scale versions called
the Sea Bee and the Sea Horse were made to
prove that they could be launched from
underwater the project came to an end
when due to budget cuts NASA's future
projects branch was closed. But even if
it had had been built it would have been
a very short life, it was just too big, there
just wasn't enough stuff to be lifted
into space to make the economies of
scale it promised viable. The technology is
still as perfectly valid today as it was
in the 1960s and maybe at some point in
the future when a large amount of
equipment is needed to be lifted into
space economically something of a
similar scale might find a role once
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