Sea Dragon (rocket)
   HOME

TheInfoList



OR:

The Sea Dragon was a 1962 conceptualized design study for a two-stage sea-launched orbital
super heavy-lift launch vehicle A super heavy-lift launch vehicle is a rocket that can lift to low Earth orbit a "super heavy payload", which is defined as more than by the United States and as more than by Russia. It is the most capable launch vehicle classification by mass ...
. The project was led by Robert Truax while working at Aerojet, one of a number of designs he created that were to be launched by floating the rocket in the ocean. Although there was some interest at both
NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
and Todd Shipyards, the project was not implemented. With dimensions of long and in diameter, Sea Dragon would have been the largest rocket ever built. , among rockets that have been fully conceived but not built, it is by far the largest ever and, in terms of payload into
low Earth orbit A low Earth orbit (LEO) is an geocentric orbit, orbit around Earth with a orbital period, period of 128 minutes or less (making at least 11.25 orbits per day) and an orbital eccentricity, eccentricity less than 0.25. Most of the artificial object ...
(LEO), equaled only by the Interplanetary Transport System concept (the predecessor to SpaceX Starship) in the latter's expendable configuration with both designed for 550 tonnes.


Design

Truax's basic idea was to produce a low-cost heavy launcher, a concept now called " big dumb booster." To lower the cost of operation, the rocket itself was launched from the ocean, requiring little in the way of support systems. A large ballast tank system attached to the bottom of the first-stage engine bell was used to "hoist" the rocket vertical for launch. In this orientation the payload at the top of the second stage was just above the waterline, making it easy to access. Truax had already experimented with this basic system in the Sea BeeSea Bee was a proof of principle program to validate the sea-launch concept. A surplus Aerobee rocket was modified so that it could be fired underwater. The rocket worked properly the first time in restrained mode. Later tests of repeat firings proved so simple that the cost of turn-around was about 7% that of a new unit. and Sea Horse.Sea Horse demonstrated sea-launch at a larger scale and on a rocket with a complex set of guidance and control systems. It used a surplus pressure fed, acid/aniline Corporal missile on a barge in San Francisco Bay. This was first fired several metres above the water, then lowered and fired in successive steps until reaching a considerable depth. Firing from underwater posed no problems and there was substantial noise attenuation. To lower the cost of the rocket, he intended it to be built of inexpensive materials, specifically steel sheeting. The rocket would be built at a sea-side shipbuilder and towed to sea for launch. It would use wide engineering margins with strong simple materials to further enhance reliability and reduce cost and complexity. The system would be at least partially reusable with passive reentry and recovery of rocket sections for refurbishment and relaunch. The first stage was to be powered by a single thrust engine burning
RP-1 RP-1 (Rocket Propellant-1 or Refined Petroleum-1) and similar fuels like RG-1 and T-1 are highly refined kerosene formulations used as rocket fuel. Liquid-fueled rockets that use RP-1 as fuel are known as kerolox rockets. In their engines, RP- ...
and LOX ( liquid oxygen). The tank pressure was for the RP-1 and for the LOX, providing a chamber pressure of at liftoff. As the vehicle climbed the pressures dropped off, eventually burning out after 81 seconds. By this point the vehicle was up and downrange, traveling at a speed of . The normal mission profile expended the stage in a high-speed splashdown some downrange, though the potential for recovering the stage was studied as well. The noise of the engine was so powerful it was the reason the rocket was to be sea launched; on land it would have torn itself apart from the vibrations, and crushed the launch pad. The second stage was also equipped with a single very large engine, in this case a thrust engine burning
liquid hydrogen Liquid hydrogen () is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecule, molecular H2 form. To exist as a liquid, H2 must be cooled below its critical point (thermodynamics), critical point of 33 Kelvins, ...
and LOX. It was also pressure-fed, at a constant lower pressure of throughout the entire 260 second burn, at which point it was up and downrange. To improve performance, the engine featured an expanding engine bell, changing from 7:1 to 27:1 expansion as it climbed. The overall height of the rocket was shortened somewhat by making the "nose" of the first stage pointed, lying inside the second-stage engine bell. A typical launch sequence would start with the rocket being refurbished and mated to its cargo and ballast tanks on shore. The RP-1 would also be loaded at this point. The rocket would then be towed to a launch site, where the LOX and LH2 would be generated on-site using
electrolysis In chemistry and manufacturing, electrolysis is a technique that uses Direct current, direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of c ...
; Truax suggested using a nuclear-powered
aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and hangar facilities for supporting, arming, deploying and recovering carrier-based aircraft, shipborne aircraft. Typically it is the ...
as a power supply during this phase. The ballast tanks, which also served as a cap and protection for the first-stage engine bell, would then be filled with water, sinking the rocket to vertical with the second stage above the waterline. Last minute checks could then be carried out and the rocket launched. The rocket would have been able to carry a payload of up to or into LEO. This is enough to comfortably launch the ISS in a single launch (which weighs a "mere" 450 tons). Payload costs, in 1963, were estimated to be between $59 and $600 per kg (roughly $500 to $5,060 per kg in 2020 dollars). TRW (Space Technology Laboratories, Inc.) conducted a program review and validated the design and its expected costs. However, budget pressures led to the closing of the Future Projects Branch, ending work on the super-heavy launchers they had proposed for a crewed mission to Mars.


Sea Dragon in fiction

The Sea Dragon appears in the first-season finale of the 2019 Apple TV+ series ''For All Mankind''. The series is set in an
alternate history Alternate history (also referred to as alternative history, allohistory, althist, or simply A.H.) is a subgenre of speculative fiction in which one or more historical events have occurred but are resolved differently than in actual history. As ...
timeline in which the 1960s-era
space race The Space Race (, ) was a 20th-century competition between the Cold War rivals, the United States and the Soviet Union, to achieve superior spaceflight capability. It had its origins in the ballistic missile-based nuclear arms race between t ...
did not end. In the post-credits scene, which takes place in 1983, a Sea Dragon is depicted launching from the Pacific Ocean to resupply the US lunar colony. An astronaut says in a voice-over that the ocean launch is being used as a safety measure because the payload includes plutonium. The Sea Dragon continues to play a role in season 2; its high payload capacity is used to resupply an expansive lunar base and is the subject of a lunar blockade by the Soviet Union. There are some small changes from the original concept compared to the version in the series, namely a lack of Launch Abort System for the Apollo capsule at the top of the rocket, and the lack of expanding second stage nozzle, instead using a large, more standard rocket engine, with four additional engines surrounding.


See also

* Aquarius (rocket)


Notes


References


Further reading

*Astronautix.com
Sea Dragon


External links


Truax Engineering Multimedia Archive

Sea Dragon Concept Volume 1 (Summary)
LRP 297 (NASA-CR-52817), 1963-01-28.
Sea Dragon Concept Volume 2
LRP 297, 1963-02-12.
Sea Dragon Concept Volume 3 (Preliminary program plan)
LRP 297 (NASA-CR-51034), 1963-02-12. * YouTube Channel Link
For All Mankind s01e10 post-credits scene. The Sea Dragon launch
* Encyclopedia Astronautica



* YouTube
Sea Dragon - 8.14
TMRO - Interview show about "Sea Dragon" * Search "Sea Dragon Concept" at th
NASA Technical Report Server
to read the unclassified design study: *
Sea Dragon Concept Volume 1 (Summary)
LRP 297 (NASA-CR-52817), 1963-01-28. *
Sea Dragon Concept Volume 3 (Preliminary program plan)
LRP 297 (NASA-CR-51034), 1963-02-12. {{DEFAULTSORT:Sea Dragon (Rocket) NASA space launch vehicles Hypothetical spacecraft Pressure-fed rockets Sea launch to orbit Cancelled space launch vehicles Proposed reusable launch systems