Redfrogcrab
Troubadour
Hi ya'll, since most of the information here is geared towards fantasy writers, I'd like to provide my own information on types of rocket engines, starting from least complex to most complex, I'll also include fuel types and subtypes
Some basic definitions:
Fuel: a substance that combusts in a combustion reaction, such as Hydrogen
Oxidizer: a substance that causes or assists a fuel in combustion, such as Oxygen
Reaction chamber: wherein an engine the reaction takes place
Throat: the part of a rocket that compresses the exhaust
Nozzle: the part that allows the exhaust to expand, producing thrust
Solid rockets: fuel is a solid or powder, can't be turned off once ignited but is incredibly simple
Liquid fuel rockets: fuel and oxidizer are a liquid that mix in a reaction chamber and are ignited, exhaust is compressed by the throat and thrown out and guided by the nozzle.
Electrostatic thrusters: Uses electro-static charges to throw a propellant (typically mercury or Xenon gas) out, extremely low thrust
Project Orion: A drive system that used timed detonations of nuclear bombs to propel a spacecraft, developed in the 1950s and 60's but for obvious reasons was never used
Nuclear thermal rockets (NTRs): use heat from a nuclear reactor to excite liquid hydrogen and cause it to exit the nozzle really fast (the hotter the exhaust, the faster the exhaust goes, and the more efficient the engine)
Nuclear saltwater rocket (NSWR): a rocket engine that uses a solution of 2% plutonium/Uranium salts (20% enriched) dissolved in water, which condense in a reaction chamber and undergo an uncontrolled fission reaction (the thing that makes nukes go kaboom), basically, it's a nuke that's constantly detonating
Fusion rockets: also known (by me and me only) as star drives, they use fusion (the reaction that makes stars, well, stars) to produce thrust, there are many variants that are to underdeveloped or complex to do justice here, most designs are hypothetical
Have you ever heard the term "unobtanium?" In aerospace, it's a material or technology that checks out on paper and is totally possible to engineer, we just lack the materials to make it. A real-world example is titanium pre-soviet collapse, where the Soviet Union had control over most of the titanium deposits on Earth. All of this is hypothetical
Here there be Unobtanium
Antimatter Rockets: uses Antimatter-Matter annihilation (a reaction that converts mass directly into energy) to produce thrust, the problem is, antimatter does not like existing near matter, which makes it bloody hard to store or even make. The best we got for containment is strong magnetic fields (which is a whole 'nother can of worms)
Metallic Hydrogen: if you compress hydrogen enough, it takes on the qualities of a metal, it's also a really good (and hot-burning) rocket fuel. Engines using this guide the exhaust with magnetic fields, since the reaction would melt most materials
Torch Drives: more of an umbrella term for any engine that has both good gas mileage and thrust, this is the holy grail of space engineering. the closest we can get now is Project Orion and the NSWR, certain fusion rocket designs are also strong torch-drive candidates
But what about systems that don't need fuel?
Photon sails: photons (the particles that make up light) have a very small amount of inertia, have a reflective sheet, you have pretty much infinite thrust, you can use photons from a star or an array of high-powered lasers to push the craft. DOES NOT WORK IN AN ATMOSPHERE OR WHERE THEIR IS NO LIGHT
I am missing a whole lot, but this is a basic reference sheet for any sci-fi writers out there.
For more: go to Atomic Rockets to get a better, more comprehensive list of engine types
Some basic definitions:
Fuel: a substance that combusts in a combustion reaction, such as Hydrogen
Oxidizer: a substance that causes or assists a fuel in combustion, such as Oxygen
Reaction chamber: wherein an engine the reaction takes place
Throat: the part of a rocket that compresses the exhaust
Nozzle: the part that allows the exhaust to expand, producing thrust
Solid rockets: fuel is a solid or powder, can't be turned off once ignited but is incredibly simple
Liquid fuel rockets: fuel and oxidizer are a liquid that mix in a reaction chamber and are ignited, exhaust is compressed by the throat and thrown out and guided by the nozzle.
Methalox: Liquid Methane+Liquid Oxygen
Hydrolox: Liquid hydrogen+Liquid Oxygen
RP-1-Oxygen: Highly pure kerosene+Liquid Oxygen
hypergolic fuels: typically some form of hydrazine+Nitrogen tetroxide, ignites instantly when the two mix
Nozzle shape: Bell: this is the classic rocket engine nozzle, the walls of the bell funnel the exhaust, short and wide bells are used in low-altitude high-power engines while long and narrow bells are used in vacuum-optimized efficient engines
Nozzle shape: Aerospike: this uses a spike-shaped nozzle and uses the fact that gas is "sticky", and works in all altitudes with out exploding
Hybrid Rockets: runs a liquid oxidizer through a solid fuel, simplicity of the Solid rockets while having the control of liquid fuel rocketsElectrostatic thrusters: Uses electro-static charges to throw a propellant (typically mercury or Xenon gas) out, extremely low thrust
Ion thrusters: bombards a neutral gas with electrons to toss them out the thruster
Hal-Effect Thruster: Like the Ion thruster, only it uses the Hal Effect
Now let's get into some SPICY propulsion systemsProject Orion: A drive system that used timed detonations of nuclear bombs to propel a spacecraft, developed in the 1950s and 60's but for obvious reasons was never used
Nuclear thermal rockets (NTRs): use heat from a nuclear reactor to excite liquid hydrogen and cause it to exit the nozzle really fast (the hotter the exhaust, the faster the exhaust goes, and the more efficient the engine)
Solid core: stick a nuclear reactor on top of a nozzle, doubles as a power plant
LANTR: Solid core design but with an additional, conventional Hydrolox "Afterburner" step
Liquid core: What's hotter than a nuclear reactor close to meltdown? A nuclear reactor that is melting down; Liquid core NTRs throw safety out the window and lets the core melt, which throws Liquid Hydrogen out even faster.
Gas core: this is getting Ridiculous, also known as a Nuclear Lightbulb, Gas-core NTRs let the reactor vaporize, which throws out liquid hydrogen even faster than previous engines
Is there anything more ridiculous?Nuclear saltwater rocket (NSWR): a rocket engine that uses a solution of 2% plutonium/Uranium salts (20% enriched) dissolved in water, which condense in a reaction chamber and undergo an uncontrolled fission reaction (the thing that makes nukes go kaboom), basically, it's a nuke that's constantly detonating
Fusion rockets: also known (by me and me only) as star drives, they use fusion (the reaction that makes stars, well, stars) to produce thrust, there are many variants that are to underdeveloped or complex to do justice here, most designs are hypothetical
Have you ever heard the term "unobtanium?" In aerospace, it's a material or technology that checks out on paper and is totally possible to engineer, we just lack the materials to make it. A real-world example is titanium pre-soviet collapse, where the Soviet Union had control over most of the titanium deposits on Earth. All of this is hypothetical
Here there be Unobtanium
Antimatter Rockets: uses Antimatter-Matter annihilation (a reaction that converts mass directly into energy) to produce thrust, the problem is, antimatter does not like existing near matter, which makes it bloody hard to store or even make. The best we got for containment is strong magnetic fields (which is a whole 'nother can of worms)
Metallic Hydrogen: if you compress hydrogen enough, it takes on the qualities of a metal, it's also a really good (and hot-burning) rocket fuel. Engines using this guide the exhaust with magnetic fields, since the reaction would melt most materials
Torch Drives: more of an umbrella term for any engine that has both good gas mileage and thrust, this is the holy grail of space engineering. the closest we can get now is Project Orion and the NSWR, certain fusion rocket designs are also strong torch-drive candidates
But what about systems that don't need fuel?
Photon sails: photons (the particles that make up light) have a very small amount of inertia, have a reflective sheet, you have pretty much infinite thrust, you can use photons from a star or an array of high-powered lasers to push the craft. DOES NOT WORK IN AN ATMOSPHERE OR WHERE THEIR IS NO LIGHT
I am missing a whole lot, but this is a basic reference sheet for any sci-fi writers out there.
For more: go to Atomic Rockets to get a better, more comprehensive list of engine types
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