Difference between revisions of "Reaction engine"
From Kerbal Space Program Wiki
(→Liquid fuel rocket engines: Efficiency rating depending on design moved from Dissadvantage to Advantage for obvious reasons.) |
(→Advantages: Vessels powered by liquid fuel are easier to refuel than vessels powered by solid fuel rockets.) |
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=== Advantages === | === Advantages === | ||
| + | * Fuel and oxidizer can be moved between liquid fuel tanks, which means that spacecraft with liquid fuel engines and fuel tanks are easier and more resource-efficient to refuel than vessels with solid fuel engines, which required the entire engine bay to be replaced, while liquid fuel and oxidizer can quickly be moved between two docked vessels. | ||
* Modular design: fuel and other components can be stored elsewhere in the craft. | * Modular design: fuel and other components can be stored elsewhere in the craft. | ||
* Throttle can be adjusted depending on thrust requirements. | * Throttle can be adjusted depending on thrust requirements. | ||
| Line 40: | Line 41: | ||
* Many nozzles can be gimballed for thrust vectoring. | * Many nozzles can be gimballed for thrust vectoring. | ||
* Efficiency largely dependent on design, with large variations. For early stages, high-output engines with low fuel-efficiency can be used to reach a low Kerbin orbit, while extremely efficient but low-power engines should be used for travelling between planets and moons to save fuel and extend the range of the craft. | * Efficiency largely dependent on design, with large variations. For early stages, high-output engines with low fuel-efficiency can be used to reach a low Kerbin orbit, while extremely efficient but low-power engines should be used for travelling between planets and moons to save fuel and extend the range of the craft. | ||
| + | |||
=== Disadvantages === | === Disadvantages === | ||
Revision as of 10:01, 22 June 2013
A rocket engine is an engine that uses nothing but its onboard propellant to generate thrust. Unlike traditional air breathing engines used by atmospheric crafts rocket engines are able to function in a vacuum where no oxygen is present.
Contents
History
Rocket engines were present in KSP in all public releases of the game.
Approaches to rocket engines
Rocket engines come in two commonly used forms. The first and most ancient type is a solid fuel rocket which is as simple as igniting a solid, self-oxidizing compound or mixture within the casing of the rocket and allowing the escaping gases to be released through a nozzle at the rear. There are currently two booster rocket sizes included.
Liquid fuel engines are powered by a liquid propellant which is comprised of combustible liquid fuel and oxidizer. In the real world typical liquid fuels are often liquid hydrogen or kerosene, and typical oxidizers are liquid oxygen or nitrous-oxide. All engines use Bell nozzles except the only aerospike engine.
Solid fuel rocket engines
Advantages
- Have a very high thrust to weight ratio.
- Engine and fuel tank are combined in one part, lowering part count, simplifying design and improving stability.
Disadvantages
- Monolithic design, must be built in one piece.
- Cannot be throttled or switched off after ignition.
- Once spent, they are unable to use fuel from another source of the craft.
Available solid fuel rocket engines
| Solid Fuel Density is 7.5 kg/unit | Mass (t) |
Fuel (  )
|
Thrust (kN) |
TWR | Isp (s) | Burn (s) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Full | Empty | |||||||||||||||||
| Image | Part | Radial size | Cost (  ) |
Full | Empty | Max. Temp. (K) |
Tolerance (m/s) |
Tolerance (g) |
atm | vac | atm | vac | atm | vac | atm | vac | ||
 |
RT-5 "Flea" Solid Fuel Booster | Small, Radial mounted | 200 (116) |
1.50 | 0.45 | 2 000 | 7 | 50 | 140 | 162.91 | 192.0 | 11.07 | 13.05 | 36.92 | 43.51 | 140 | 165 | 8.8 |
 |
RT-10 "Hammer" Solid Fuel Booster | Small, Radial mounted | 400 (175) |
3.56 | 0.75 | 2 000 | 7 | 50 | 375 | 197.90 | 227.0 | 5.66 | 6.50 | 26.91 | 30.86 | 170 | 195 | 23.7 |
 |
BACC "Thumper" Solid Fuel Booster | Small, Radial mounted | 850 (358) |
7.65 | 1.50 | 2 200 | 7 | 50 | 820 | 250.00 | 300.0 | 3.33 | 4.00 | 17.00 | 20.39 | 175 | 210 | 42.2 |
 |
S1 SRB-KD25k "Kickback" Solid Fuel Booster | Small, Radial mounted | 2 700 (1 140) |
24.00 | 4.50 | 2 200 | 7 | 50 | 2 600 | 593.86 | 670.0 | 2.52 | 2.85 | 13.46 | 15.18 | 195 | 220 | 62.8 |
 |
Sepratron I | Radial mounted | 75 (70.2) |
0.0725 | 0.0125 | 2 000 | 7 | 50 | 8 | 13.79 | 18.0 | 19.40 | 25.32 | 112.51 | 146.84 | 118 | 154 | 5.0 |
 |
FM1 "Mite" Solid Fuel Booster | Tiny, Radial mounted | 75 (51.0) |
0.375 | 0.075 | 2 200 | 7 | 50 | 40 | 11.012 | 12.5 | 2.93 | 3.33 | 14.68 | 16.66 | 185 | 210 | 49.44 |
 |
F3S0 "Shrimp" Solid Fuel Booster | Tiny, Radial mounted | 150 (96.0) |
0.875 | 0.155 | 2 200 | 7 | 50 | 90 | 26.512 | 30.0 | 3.22 | 3.65 | 17.1 | 19.35 | 190 | 215 | 47.44 |
 |
S2-17 "Thoroughbred" Solid Fuel Booster | Large, Radial mounted | 9 000 (4 200.0) |
70.00 | 10.00 | 2 200 | 10 | 50 | 8 000 | 1 515.217 | 1 700.0 | 2.16 | 2.43 | 15.15 | 17.0 | 205 | 230 | 79.6 |
 |
S2-33 "Clydesdale" Solid Fuel Booster | Large, Radial mounted | 18 500 (8 660.0) |
144.00 | 21.00 | 2 200 | 10 | 50 | 16 400 | 2 948.936 | 3 300.0 | 2.05 | 2.29 | 14.04 | 15.71 | 210 | 235 | 85.9 |
Liquid fuel rocket engines
Advantages
- Fuel and oxidizer can be moved between liquid fuel tanks, which means that spacecraft with liquid fuel engines and fuel tanks are easier and more resource-efficient to refuel than vessels with solid fuel engines, which required the entire engine bay to be replaced, while liquid fuel and oxidizer can quickly be moved between two docked vessels.
- Modular design: fuel and other components can be stored elsewhere in the craft.
- Throttle can be adjusted depending on thrust requirements.
- Can be switched off and re-ignited at will.
- Many nozzles can be gimballed for thrust vectoring.
- Efficiency largely dependent on design, with large variations. For early stages, high-output engines with low fuel-efficiency can be used to reach a low Kerbin orbit, while extremely efficient but low-power engines should be used for travelling between planets and moons to save fuel and extend the range of the craft.
Disadvantages
- Lower power to weight ratio compared to solid rocket engines.
- Complex design with fuel tanks and other additional components.
- More points of possible failure such as if the parts tear apart from stress.
Available liquid fuel rocket engines
| Thrust (kN) |
T/W ratio |
Max. Fuel Consumption ( /s)
|
Isp (s) | TVC | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Image | Part | Radial size | Cost ( ) |
Mass (t) |
Max. Temp. (K) |
Tolerance (m/s) |
Tolerance (g) |
atm | vac | atm | vac | atm | vac | Gimbal (°) | |
 |
LV-1R "Spider" Liquid Fuel Engine | Radial mounted | 120 | 0.02 | 2 000 | 7 | 50 | 1.79 | 2.0 | 9.14 | 10.20 | 0.141 | 260 | 290 | 10.0 |
 |
24-77 "Twitch" Liquid Fuel Engine | Radial mounted | 230 | 0.08 | 2 000 | 7 | 50 | 15.17 | 16.0 | 19.34 | 20.39 | 1.125 | 275 | 290 | 8.0 |
 |
Mk-55 "Thud" Liquid Fuel Engine | Radial mounted | 820 | 0.90 | 2 000 | 7 | 50 | 108.20 | 120.0 | 12.26 | 13.60 | 8.024 | 275 | 305 | 8.0 |
 |
O-10 "Puff" MonoPropellant Fuel Engine[Note 1] | Radial mounted | 150 | 0.09 | 2 000 | 7 | 50 | 9.60 | 20.0 | 10.88 | 22.66 | 2.039 | 120 | 250 | 6.0 |
 |
LV-1 "Ant" Liquid Fuel Engine | Tiny, Radial mounted | 110 | 0.02 | 2 000 | 7 | 50 | 0.51 | 2.0 | 2.59 | 10.20 | 0.129 | 80 | 315 | — |
 |
48-7S "Spark" Liquid Fuel Engine | Tiny | 240 | 0.13 | 2 000 | 7 | 50 | 16.56 | 20.0 | 12.99 | 15.69 | 1.275 | 265 | 320 | 3.0 |
 |
LV-909 "Terrier" Liquid Fuel Engine | Small | 390 | 0.50 | 2 000 | 7 | 50 | 14.78 | 60.0 | 3.01 | 12.24 | 3.547 | 85 | 345 | 4.0 |
 |
LV-T30 "Reliant" Liquid Fuel Engine | Small | 1 100 | 1.25 | 2 000 | 7 | 50 | 205.16 | 240.0 | 16.74 | 19.58 | 15.789 | 265 | 310 | — |
 |
LV-T45 "Swivel" Liquid Fuel Engine | Small | 1 200 | 1.50 | 2 000 | 7 | 50 | 167.97 | 215.0 | 11.42 | 14.62 | 13.703 | 250 | 320 | 3.0 |
 |
S3 KS-25 "Vector" Liquid Fuel Engine | Small, Radial mounted | 18 000 | 4.00 | 2 000 | 22 | 50 | 936.51 | 1 000.0 | 23.87 | 25.49 | 64.745 | 295 | 315 | 10.5 |
 |
T-1 Toroidal Aerospike "Dart" Liquid Fuel Engine | Small, Radial mounted | 3 850 | 1.00 | 2 000 | 20 | 50 | 153.53 | 180.0 | 15.66 | 18.35 | 10.797 | 290 | 340 | — |
 |
LV-N "Nerv" Atomic Rocket Motor[Note 2] | Small | 10 000 | 3.00 | 2 500 | 12 | 50 | 13.88 | 60.0 | 0.47 | 2.04 | 1.530 | 185 | 800 | — |
 |
RE-L10 "Poodle" Liquid Fuel Engine | Large | 1 300 | 1.75 | 2 000 | 7 | 50 | 64.29 | 250.0 | 3.75 | 14.57 | 14.568 | 90 | 350 | 4.5 |
 |
RE-I5 "Skipper" Liquid Fuel Engine | Large | 5 300 | 3.00 | 2 000 | 8 | 50 | 568.75 | 650.0 | 19.33 | 22.09 | 41.426 | 280 | 320 | 2.0 |
 |
RE-M3 "Mainsail" Liquid Fuel Engine | Large | 13 000 | 6.00 | 2 000 | 7 | 50 | 1 379.03 | 1 500.0 | 23.44 | 25.49 | 98.683 | 285 | 310 | 2.0 |
 |
LFB KR-1x2 "Twin-Boar" Liquid Fuel Engine[Note 3] | Large, Radial mounted | 17 000 (14 062.4) |
42.50 (10.50) |
2 000 | 20 | 50 | 1 866.67 | 2 000.0 | 4.48 (18.13) |
4.80 (19.42) |
135.964 | 280 | 300 | 1.5 |
 |
Kerbodyne KR-2L+ "Rhino" Liquid Fuel Engine | Extra large | 25 000 | 9.00 | 2 000 | 7 | 50 | 1 205.88 | 2 000.0 | 13.66 | 22.66 | 119.968 | 205 | 340 | 4.0 |
 |
S3 KS-25x4 "Mammoth" Liquid Fuel Engine | Extra large | 39 000 | 15.00 | 2 000 | 20 | 50 | 3 746.03 | 4 000.0 | 25.47 | 27.19 | 258.978 | 295 | 315 | 2.0 |
 |
CR-7 R.A.P.I.E.R. Engine[Note 4] | Small | 6 000 | 2.00 | 2 000 | 20 | 50 | 162.30 | 180.0 | 8.27 | 9.18 | 12.036 | 275 | 305 | 3.0 |
- ↑ Consumes monopropellant. (the density of monopropellant is less: 4kg/unit)
- ↑ Consumes liquid fuel only.
- ↑ The LFB KR-1x2 is a liquid fuel booster -- a combination of a "normal" engine and a fuel tank.
- ↑ The R.A.P.I.E.R. Engine is a combination of liquid fuel and jet engine. Only the liquid fuel engine properties are shown.
