Plasma Engine
- Mass: 0.167 t
- Maximum Power: 3.125 GW
- Mass: 1 t
- Maximum Power: 25 GW
- Mass: 6 t
- Maximum Power: 200 GW
Instead of generating thrust directly from thermal power, it is possible to use electricity to power plasma propulsion systems. These propulsion systems offer slightly different characteristics than thermal rockets, tending to produce remarkable specific impulses but far lower levels of thrust. Getting large enough power plants into orbit to propel these creations across space is a challenge for any space program but the results, if successful, can be staggering.
This part will automatically detect the amount of electrical power available from any electrical generators attached to the ship and will scale its power consumption accordingly. Thrust is determined by the amount of power consumed, while specific impulse is solely determined by choice of propellant. The different sizes of plasma engine are functionally identical in all ways, except the larger engines have a larger cap on the maximum amount power they can use. Attaching larger engines or multiple engines will only increase your thrust if you have enough power to hit the cap.
The plasma engine can use multiple types of fuels. You can toggle between Liquid Fuel (Hydrogen), Lithium, Monopropellant (Hydrazine), Argon and Xenon. Liquid Fuel offers the best specific impulse and lowest thrust, while Xenon offers the most thrust but the least specific impulse. The others are in between in the order they are listed above. When upgraded, the plasma engine is capable of pushing against the quantum vacuum itself to provide thrust. This mode only functions while not in an atmosphere and has the same performance as liquid fuel. However, while in this mode it requires only electricity and no fuel whatsoever.
The plasma engine is not perfectly efficient at turning electricity into thrust. The different propellants have different efficiencies. This determines how much of the consumed power is converted into thrust. It also determines how much Waste Heat the plasma engine produces - the less efficient the propellant, the more energy is wasted as heat.
This is a table of the thrusts you will get from a plasma engine powered by one reactor+generator in all the upgrade configurations, i.e. no upgraded parts, just the reactor upgraded, just the generator upgraded and both parts upgraded. This list is by no means exhaustive of the possible combinations you might have.
- Specific Impulse: 11,213 s
- Efficiency: 72%
- Thrust: 0.0131 kN per megawatt
- Specific Impulse: 6,470 s
- Efficiency: 86%
- Thrust: 0.0227 kN per megawatt
- Specific Impulse: 2,803 s
- Efficiency: 52%
- Thrust: 0.0524 kN per megawatt
- Specific Impulse: 2,491 s
- Efficiency: 76%
- Thrust: 0.0589 kN per megawatt
- Specific Impulse: 1,384 s
- Efficiency: 69%
- Thrust: 0.1061 kN per megawatt