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Louis Bach edited this page Jan 19, 2021 · 10 revisions

Engines are listed here roughly in order of their appearance in the tech tree.

Contents

1,500 Science tech tier:

2,250 Science tech tier:

4,000 Science tech tier:

10,000 Science tech tier:

X-6 'Clarke' Fission Fragment Rocket Engine

X-6 'Clarke' Fission Fragment Rocket Engine
Technology: Experimental Nuclear Propulsion (1,500)
Diameter: 2.5
Mass: 10
Cost: 195,000
Propellant: Enriched Uranium
Thrust: 12
Specific Impulse: 350,000
Heat Production: 15,000

This novel engine considers an important question: what if you just stuck an open nuclear reactor core on the back of a spacecraft? The spinning platters in the core are coated with uranium dust, and undergo fission as they spin through the core. The fission products fly out the back at ludicrous speeds, resulting in maddeningly high specific impulse! A secondary set of magnets decelerates stray fragments, inducing a current in powerful generator coils. This creates enough power to run the engine system and more, so once this engine is running, it produces an acceptable 75 kW of electricity. However, there are downsides - barely noticeable thrust, no refuelability, and radioactivity, lots of radioactivity.

X-20 'Verne' Pulsed Fission Engine

X-20 'Verne' Pulsed Fission Engine
Technology: Experimental Nuclear Propulsion (1,500)
Diameter: 5
Mass: 18
Cost: 355,000
Propellant: Fission Pellets
Thrust: 640
Specific Impulse: 9,500
Heat Production: 13,000

A curious property of really, really high currents - when arranged properly, they generate a collapsingmagnetic field. This engine exploits this by directing pulses of extremely high current into small fission bombs, which explode with moderate force and are directed backwards by a magnetic nozzle. It's a mini Orion drive, without the powerful nukes, higher efficiency and the need for big blue capacitors.

JP-10 'Impulse' Magneto-Inertial Fusion Engine

JP-10 'Impulse' Magneto-Inertial Fusion Engine
Technology: Fusion Rockets (1,500)
Diameter: 2.5
Mass: 11
Cost: 96,000
Mode: Deuterium D-He3
Propellant: Lithium/LqdDeuterium Lithium/LqdDeuterium/LqdHe3
Thrust: 75 100
Specific Impulse: 5,000 7,500
Heat: 3,000 3,000

Simple, entry-level fusion by using cylindrical plasma liners made of lithium, crushed by magnetic coils. These coils crush fuel gases which undergo fusion. Deuterium or a Deuterium-He3 mix can be used - using the higher performance fuel increases power and decreases heat generation. This engine needs to charge its power banks to be activated, and still uses a small amount of power when running.

X-7 'Asimov' Afterburning Fission Fragment Rocket Engine

X-7 'Asimov' Afterburning Fission Fragment Rocket Engine
Technology: Exotic Nuclear Propulsion (2,250)
Diameter: 3.75
Mass: 18
Cost: 275,000
Mode: Fission Fragment Afterburner
Propellant: FissionParticles FissionParticles/LH2
Thrust: 30 300
Specific Impulse: 450,000 45,000
Heat: 16,000 12,500

A direct improvement on the fission fragment platter design, this engine suspends a particulate dust of fissionable particles in the centre of a reaction chamber using a weak magnetic field. The dust undergoes fission, and the reaction products are expelled at high energy from the rocket at incredible speeds, guided but not restrained by the magnetic field. A secondary set of magnets decelerates stray fragments, inducing a current in powerful generator coils. This creates enough power to run the engine system and more, so once this engine is running, it produces an acceptable 125 kW of electricity. In order to try to boost the thrust, Liquid Hydrogen can be injected into the beam of radioactive death, cutting efficiency but improving thrust from barely noticeable to merely pitiful.

X-2 'Heinlein' Nuclear Salt Water Rocket Engine

X-2 'Heinlein' Nuclear Salt Water Rocket Engine
Technology: Exotic Nuclear Propulsion (2,250)
Diameter: 2.5
Mass: 12
Cost: 115,000
Propellant: NuclearSaltWater
Thrust: 1,800
Specific Impulse: 3,850
Heat Production: 8,000

Basically a continuously detonating, barely contained nuclear explosion, this rocket engine is highly radioactive, highly unpleasant and highly... awesome.

JR-15 'Discovery' Spherical Tokamak Fusion Engine

JR-15 'Discovery' Spherical Tokamak Fusion Engine
Technology: Advanced Fusion Reactions (2,250)
Diameter: 3.75
Mass: 20
Cost: 235,000
Mode: Low Power High Power
Propellant: LH2/LqdDeuterium/LqdHe3 LH2/LqdDeuterium/LqdHe3
Thrust: 200 400
Specific Impulse: 17,900 8,000
Heat: 14,000 7,000

This basic thermal fusion engine reacts Helium-3 and Deuterium in a spherical tokamak design. A variable amount of Liquid Hydrogen can be injected into the exhaust, increasing thrust at the cost of efficiency. This engine needs to charge its power banks to be activated, but can produce a cool 500 kW of power from onboard fusion fuel once activated, even if the engine isn't running. Keeping the reactor running in this way allows instant throttle response. Make sure to pack radiators!

JR-45 'Fresnel' Mirror Cell Fusion Engine

JR-45 'Fresnel' Mirror Cell Fusion Engine
Technology: Exotic Fusion Reactions (4,000)
Diameter: 3.75
Mass: 50
Cost: 585,000
Note: Stats are given for maximum length (22m)
Mode: Reaction Products Afterburner
Propellant: LqdDeuterium/LqdHe3 LH2/LqdDeuterium/LqdHe3
Thrust: 375 1,875
Specific Impulse: 200,000 40,000
Heat: 45,000 28,000

The long, thin plasma chamber of the gasdynamic mirror engine does away with confining the plasma for fusion and says 'why not just throw it down a long, narrow hallway and hope it fuses by the end of it?'. This gives great energy release and high possible fusion gain. Hydrogen can optionally be injected into the plasma for additional thrust. The length of the reaction chamber determines the performance of the engine - higher lengths cost and weigh more, but net great dividends. This engine needs to charge its power banks to be activated, but can produce a modest 250 kW of power from onboard fusion fuel once activated, even if the engine isn't running. Keeping the reactor running in this way allows instant throttle response. Make sure to pack radiators!

A-134NG 'Casaba' Antimatter Catalyzed Microfission Engine

A-134NG 'Casaba' Antimatter Catalyzed Microfission Engine
Technology: Antimatter Power (4,000)
Diameter: 5.00 (attachment), 7.50 (engine bell)
Mass: 15
Cost: 355,000
Propellant: Ablator/Antimatter/FissionPellets
Thrust: 420
Specific Impulse: 13,500
Heat Production: 11,200

This engine detonates small nuclear charges with precisely directed beams of antiprotons. Simple, really. Antimatter... triggered... nuclear... bombs. The blast from the charges vaporizes an ablative nozzle, providing high efficiency thrust. This engine needs to charge its power banks to be activated, but onboard generation systems ensures that it will run independently once it gets going.

A-7007 'Dirac' Antimatter Initiated Microfusion Engine

A-7007 'Dirac' Antimatter Initiated Microfusion Engine
Technology: Antimatter Power (4,000)
Diameter: 2.5
Mass: 10
Cost: 670,000
Propellant: Antimatter/LqdDeuterium/LqdHe3
Thrust: 45
Specific Impulse: 115,000
Heat Production: 4,000

This engine leverages antimatter to help small quantities of deuterium and Helium-3 along to fusion temperatures, producing efficient, albeit low-thrust propulsion with smaller mass and volumes compared to inertial or magnetically confined containment. Can also function as a fusion reactor producing a modest 200 kW of power.

K-80 'Hammertong' Inertial Confinement Fusion Engine

K-80 'Hammertong' Inertial Confinement Fusion Engine
Technology: High Density Fusion Reactions (10,000)
Diameter: 5
Mass: 45
Cost: 730,000
Mode: Reaction Products Low Density
Propellant: LqdDeuterium/LqdHe3 LqdDeuterium/LqdHe3
Thrust: 40 80
Specific Impulse: 520,000 260,000
Heat: 30,500 25,500

Commence primary ignition! A precisely timed array of high-power laser beams converges on a single isolated pellet of Deuterium and Helium-3, generated in the onboard pellet factory. Vaporization of the outer shell compresses the fuels to a high degree, initiating fusion of the core. This model of drive uses only reaction products as exhaust using a powerful magnetic nozzle, resulting in a great specific impulse but a low thrust. Additional Deuterium feedstock can be used in each pellet, modestly increasing thrust. This engine needs to charge its power banks to be activated, but uses no energy while running.

JR-20A 'Ouroboros' Torroidal Tokamak Fusion Engine

JR-20A 'Ouroboros' Torroidal Tokamak Fusion Engine
Technology: High Density Fusion Reactions (10,000)
Diameter: 2.5
Mass: 11
Cost: 670,000
Propellant: LH2/LqdDeuterium/LqdHe3
Thrust: 1,500
Specific Impulse: 1,900
Heat Production: 7,500

This advanced magnetic fusion engine reacts Helium-3 and Deuterium in a spherical tokamak design. The reaction system has been optimized to heat large quantities of Liquid Hydrogen, resulting in higher thrust but much lower specific impulse than other fusion systems. The use of an aerospike nozzle allows effective atmospheric operation. To reduce weight, this engine's onboard reactor does not produce a significant amount of power when running, though keeping the reactor active in this way allows instant throttle response. Make sure to pack radiators!

JX-200 'Cascade' Axial Flow Z-Pinch Fusion Engine

JX-200 'Cascade' Axial Flow Z-Pinch Fusion Engine
Technology: Unified Field Theory (10,000)
Diameter: 3.75
Mass: 32
Cost: 235,000
Mode: Reaction Products Afterburner
Propellant: LqdDeuterium/LqdHe3 LH2/LqdDeuterium/LqdHe3
Thrust: 1,100 2,800
Specific Impulse: 265,000 85,000
Heat: 54,000 36,000

This engine uses a combination of magnetic confinement and zeta-pinch effects to compress fusion plasmas highly efficiently. This results in great performance as the plume of nuclear fire sprays out the back of the 'open concept' reaction chamber. This engine needs to charge its power banks to be activated, but once running generates up to 750 kW of electrical power siphoned off from the plasma stream to charge ship power banks.

A-834M 'Frisbee' Antimatter Engine

A-834M 'Frisbee' Antimatter Engine
Technology: Unified Field Theory (10,000)
Diameter: 5.00 (attachment), 10.00 (engine bell)
Mass: 85
Cost: 432,500
Note: Stats are given for maximum length (110m)
Propellant: Antimatter/LH2
Thrust: 6,000
Specific Impulse: 775,000
Heat Production: 0

An endgame torch drive, the Frisbee reacts large quantities of matter with large quantities of antimatter. The resulting multi-kilometre beam of reaction products provides excellent impulse and adequate thrust. Unfortunately, the vast amounts of high energy gamma rays make the engine large, unwieldy and prone to overheating. Luckily, the integrated radiator truss can be extended to reject a fair amount of heat without adding separate radiator parts. When at its full 110m length, no additional radiators are needed to cool the engine.