Difference between revisions of "Reaction engine"

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(Resource-centric corrections. Work now and after move to Rocket engine)
(+jets)
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[[File:LV-T30 Liquid Fuel Engine.jpg|right|thumb|[[LV-T30 Liquid Fuel Engine]] before [[0.18]]]]
 
[[File:LV-T30 Liquid Fuel Engine.jpg|right|thumb|[[LV-T30 Liquid Fuel Engine]] before [[0.18]]]]
  
−
A '''reaction engine''' is an [[engine]] that generates thrust by expelling reaction mass in accordance with Newton's third law. In [[Kerbal Space Program]] this can be interpreted to mean any engine that expends [[fuel]] as a resource. Unlike [[jet engine]]s, which require [[intake air]] to operate, rocket engines carry [[oxidizer]] and thus are able to function regardless of whether an [[oxygen]]-rich [[atmosphere]] is present or not.
+
A '''reaction engine''' is an [[engine]] that generates thrust by expelling reaction mass in accordance with Newton's third law. Their classification differs by sources a bit, but all contradistinguish the [[intake air|air]] dependent [[jet engine]]s from the others, independently from the usage of the [[oxygen]] of the [[atmosphere]] or not. The rest of them use on-board propellant for expelling reaction mass, making them independent from the atmosphere - these are the widely defined “rocket engines”. The propellant can be expelled by outer energy source like the [[ion engine]]s ([[electricity]]) or nuclear-thermal rocket motors (nuclear power) do, or the expelled propellant is the source of that energy. This energy can derive from physical state of the propellant gas (cold rockets), or the chemical reactions of the propellant cover the energy need of the acceleration of the projected gas (these are the classical chemical rocket engines). There are many types of the propellants of these engines, but in the [[Kerbal Space Program]] the variety of the propellants are restricted to [[solid fuel]], [[liquid fuel]] - [[oxidizer]] mix in 9:11 ratio, and the [[monopropellant]].
  
 
== Physics ==
 
== Physics ==
Line 16: Line 16:
  
 
=== Disadvantages ===
 
=== Disadvantages ===
−
 
 
* Cannot be throttled or switched off after ignition.
 
* Cannot be throttled or switched off after ignition.
 
* Cannot be refueled or use fuel stored elsewhere on the craft.
 
* Cannot be refueled or use fuel stored elsewhere on the craft.
Line 27: Line 26:
  
 
== Liquid fuel rocket engines ==
 
== Liquid fuel rocket engines ==
−
Liquid fuel engines are powered by [[liquid fuel]] ignited with liquid [[oxidizer]]. In the real world, typical liquid fuels are liquid hydrogen or kerosene, and typical oxidizers are liquid oxygen or nitrous-oxide. All engines use [[w:Bell nozzle|Bell nozzles]] except the [[w:Aerospike engine|aerospike engine]].
+
Liquid fuel engines are powered by [[liquid fuel]] ignited with liquid [[oxidizer]], except of the [[O-10 MonoPropellant Engine]]. In the real world, typical liquid fuels are liquid hydrogen or kerosene, and typical oxidizers are liquid oxygen or nitrous-oxide. All engines use [[w:Bell nozzle|Bell nozzles]] except the [[w:Aerospike engine|aerospike engine]].
  
 
The [[LV-N Atomic Rocket Motor]] was inspired by real-world nuclear thermal rockets, such as the [[w:NERVA|NERVA]].  Nuclear thermal rockets use a different propulsion model; the propellant (typically liquid hydrogen) is heated in a nuclear reactor rather than being combined with an oxidizer.  However, in order to reduce development effort and to simplify gameplay, [[Squad]] chose to permit the LV-N to use the same fuel combination as other in-game liquid-fuel engines.
 
The [[LV-N Atomic Rocket Motor]] was inspired by real-world nuclear thermal rockets, such as the [[w:NERVA|NERVA]].  Nuclear thermal rockets use a different propulsion model; the propellant (typically liquid hydrogen) is heated in a nuclear reactor rather than being combined with an oxidizer.  However, in order to reduce development effort and to simplify gameplay, [[Squad]] chose to permit the LV-N to use the same fuel combination as other in-game liquid-fuel engines.
−
 
  
 
=== Advantages ===
 
=== Advantages ===
−
 
 
* Fuel and oxidizer can be moved between tanks. This opens many possibilities for fuel management and logistics, including replenishing the fuel supply of a craft already in flight.
 
* Fuel and oxidizer can be moved between tanks. This opens many possibilities for fuel management and logistics, including replenishing the fuel supply of a craft already in flight.
 
* Engines and fuel need not be mounted in the same location on the ship, expanding design possibilities.
 
* Engines and fuel need not be mounted in the same location on the ship, expanding design possibilities.
Line 41: Line 38:
  
 
=== Disadvantages ===
 
=== Disadvantages ===
−
 
 
* Lower [[thrust-to-weight ratio]] compared to solid rocket engines.
 
* Lower [[thrust-to-weight ratio]] compared to solid rocket engines.
 
* Separation of engine and fuel leads to increased part count for all except the [[LFB KR-1x2|KR-1x2]].
 
* Separation of engine and fuel leads to increased part count for all except the [[LFB KR-1x2|KR-1x2]].
Line 52: Line 48:
 
|title=Available liquid fuel tanks
 
|title=Available liquid fuel tanks
 
|content={{Stats Table Liquid Fuel Tanks}}
 
|content={{Stats Table Liquid Fuel Tanks}}
 +
}}
 +
 +
== RCS thrusters ==
 +
[[RCS]] thrusters use their own fuel, [[monopropellant]] (except of the liquid fuel - oxidizer consuming [[Vernor Engine]]), and do not require a separate oxidizer. RCS is primarily used for steering a craft or making very small positional adjustments during [[docking]]; it is too weak and inefficient to function as a main maneuvering engine.
 +
 +
=== Advantages ===
 +
* [[Monopropellant]] is automatically distributed throughout a vehicle and does not require [[FTX-2 External Fuel Duct|crossfeeding]] to be manually set up.
 +
 +
=== Disadvantages ===
 +
* Very low thrust. The available RCS thrusters are too weak to lift off from most [[celestial body|celestial bodies]].
 +
* No thrust vectoring is available (however, the most commonly use thruster, the [[RV-105 RCS Thruster Block]], can thrust in 4 directions).
 +
* The user can only switch engines on or off, while the SAS can run them on different thrust levels in between.
 +
* Low efficiency.
 +
 +
{{FlipBox
 +
|title=Available RCS engines
 +
|content={{Stats Table RCS Thrusters}}
 +
}}
 +
{{FlipBox
 +
|title=Available monopropellant tanks
 +
|content={{Stats Table RCS Fuel}}
 
}}
 
}}
  
Line 69: Line 86:
 
}}
 
}}
  
−
== RCS thrusters ==
+
== Jet engines ==
−
[[RCS]] thrusters use their own fuel, [[monopropellant]], and do not require a separate oxidizer. RCS is primarily used for steering a craft or making very small positional adjustments during [[docking]]; it is too weak and inefficient to function as a main maneuvering engine.
+
Unlike rocket engines, jets propels the intake air (mainly), and draws oxygen from the atmosphere rather than taking it from an on-board tank. This is represented in-game by a much lower rate of fuel consumption. As they do so the classical rocket equation doesn't valid for them, and also they depends on the properly dense atmosphere consisting the vital oxygen.
  
 
=== Advantages ===
 
=== Advantages ===
−
* [[Monopropellant]] is automatically distributed throughout a vehicle and does not require [[FTX-2 External Fuel Duct|crossfeeding]] to be manually set up.
+
* Provides excellent fuel efficiency within an atmosphere
 +
* All current jet engines provide thrust vectoring for greater maneuverability
 +
* Excellent power to weight ratio
  
 
=== Disadvantages ===
 
=== Disadvantages ===
−
* Very low thrust. The available RCS thrusters are too weak to lift off from most [[celestial body|celestial bodies]].
+
* Cannot be used outside of an atmosphere that contains oxygen. In current version, it means they only function on [[Kerbin]] and [[Laythe]].
−
* No thrust vectoring is available (however, the most commonly use thruster, the [[RV-105 RCS Thruster Block]], can thrust in 4 directions).
+
* Thrust output changes depending on speed
−
* The user can only switch engines on or off, while the SAS can run them on different thrust levels in between.
+
* Engine requires time to spool up to maximum thrust potential
−
* Low efficiency.
 
  
 
{{FlipBox
 
{{FlipBox
−
|title=Available RCS engines
+
|title=Available jet engines
−
|content={{Stats Table RCS Thrusters}}
+
|content={{Stats Table Jet Engines}}
 
}}
 
}}
  

Revision as of 16:10, 8 March 2015

LV-T30 Liquid Fuel Engine before 0.18

A reaction engine is an engine that generates thrust by expelling reaction mass in accordance with Newton's third law. Their classification differs by sources a bit, but all contradistinguish the air dependent jet engines from the others, independently from the usage of the oxygen of the atmosphere or not. The rest of them use on-board propellant for expelling reaction mass, making them independent from the atmosphere - these are the widely defined “rocket engines”. The propellant can be expelled by outer energy source like the ion engines (electricity) or nuclear-thermal rocket motors (nuclear power) do, or the expelled propellant is the source of that energy. This energy can derive from physical state of the propellant gas (cold rockets), or the chemical reactions of the propellant cover the energy need of the acceleration of the projected gas (these are the classical chemical rocket engines). There are many types of the propellants of these engines, but in the Kerbal Space Program the variety of the propellants are restricted to solid fuel, liquid fuel - oxidizer mix in 9:11 ratio, and the monopropellant.

Physics

All reaction engine work with the same principle: mass is propelled out of the nozzle which accelerates the vehicle due to Newton's third law of motion. Every engine in the game uses this basic principle, differing in the environments in which they will function (jet engines require an oxygen-rich atmosphere), the types of fuel they consume (ion engines require the vehicle to mount xenon tanks), and the game controls which activate them (RCS thrusters respond to directional controls, all others respond to the throttle).

Solid fuel rocket engines

→ Main article: Solid rocket booster

The most basic type is the solid fuel rocket, which is simply a solid, self-oxidizing compound or mixture within a casing with a nozzle at the rear to allow the gases produced to escape.

Advantages

  • Very high thrust-to-weight ratio.
  • Engine and fuel tank are combined in one part, lowering part count and simplifying design.

Disadvantages

  • Cannot be throttled or switched off after ignition.
  • Cannot be refueled or use fuel stored elsewhere on the craft.
  • Low efficiency compared to other types of engines.
Available solid fuel rocket engines
Solid Fuel Density is 7.5 kg/unit Mass
(t) 		Fuel
(Units of fuel) 		Thrust
(kN) 		TWR Isp (s) Burn
(s)
Full Empty
Image Part Radial size Cost
(Funds)		 Full Empty Max. Temp.
(K)		 Tolerance
(m/s)		 Tolerance
(g) 		atm vac atm vac atm vac atm vac
RT-5 White.png
 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 White.png
 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 SFB.png
 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
SRB.png
 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.png
 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
Mite.png
 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
Shrimp.png
 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
Thorougbred.png
 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
Clydesdale.png
 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

Liquid fuel engines are powered by liquid fuel ignited with liquid oxidizer, except of the O-10 MonoPropellant Engine. In the real world, typical liquid fuels are liquid hydrogen or kerosene, and typical oxidizers are liquid oxygen or nitrous-oxide. All engines use Bell nozzles except the aerospike engine.

The LV-N Atomic Rocket Motor was inspired by real-world nuclear thermal rockets, such as the NERVA. Nuclear thermal rockets use a different propulsion model; the propellant (typically liquid hydrogen) is heated in a nuclear reactor rather than being combined with an oxidizer. However, in order to reduce development effort and to simplify gameplay, Squad chose to permit the LV-N to use the same fuel combination as other in-game liquid-fuel engines.

Advantages

  • Fuel and oxidizer can be moved between tanks. This opens many possibilities for fuel management and logistics, including replenishing the fuel supply of a craft already in flight.
  • Engines and fuel need not be mounted in the same location on the ship, expanding design possibilities.
  • Variable throttle allows different levels of thrust at different times, or for the engines to be shut down entirely and restarted later in the flight.
  • Some liquid engines have gimbals which allows them to help steer the craft.
  • Available in a wide range of thrusts and efficiencies, all of which may share fuel with each other.

Disadvantages

  • Lower thrust-to-weight ratio compared to solid rocket engines.
  • Separation of engine and fuel leads to increased part count for all except the KR-1x2.
Available liquid fuel rocket engines
Thrust
(kN) 		T/W
ratio 		Max. Fuel
Consumption
(Units of fuel/s) 		Isp (s) TVC
Image Part Radial size Cost
(Funds)		 Mass
(t)		 Max. Temp.
(K)		 Tolerance
(m/s)		 Tolerance
(g) 		atm vac atm vac atm vac Gimbal
(°)
LV-1R Shroud.png
 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 Orange.png
 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 Radial mount engine.png
 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.png
 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 Shroud.png
 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 Shroud.png
 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 Shroud.png
 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 Liquid Fuel Engine recent.png
 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 LFE.png
 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
KS-25 LFE.png
 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
ToroidalAerospikeLiquidFuelEngine.png
 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 Atomic.png
 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.png
 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
SkipperV2.png
 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
MainsailV2.png
 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.png
 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
Big1.png
 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
Quad.png
 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
Rapier Engine 01.png
 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
  1. ↑ Consumes monopropellant. (the density of monopropellant is less: 4kg/unit)
  2. ↑ Consumes liquid fuel only.
  3. ↑ The LFB KR-1x2 is a liquid fuel booster -- a combination of a "normal" engine and a fuel tank.
  4. ↑ 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.
Available liquid fuel tanks
Liquid fuel and oxidizer density are both 5 kg/unit Mass
(t) 		Liquid
Fuel
(Units of fuel) 		Oxidizer
(Units of fuel)
Image Part Radial size Cost
(Funds)		 Full Empty Max. Temp.
(K)		 Tolerance
(m/s)		 Tolerance
(g)
R-4 FT.png
 R-4 'Dumpling' External Tank X 50
(39.90) 		0.1238 0.0138 2 000 5 50 9.9 12.1
R-11 FT.png
 R-11 'Baguette' External Tank X 50
(25.21) 		0.3038 0.0338 2 000 5 50 24.3 29.7
R-12 FT.png
 R-12 'Doughnut' External Tank Small 147
(119.46) 		0.3375 0.0375 2 000 6 50 27 33
Oscar-B FT.png
 Oscar-B Fuel Tank Tiny 70
(51.64) 		0.225 0.025 2 000 6 50 18 22
FL-T100 Dark.png
 FL-T100 Fuel Tank Small 150
(104.1) 		0.5625 0.0625 2 000 6 50 45 55
FL-T200 Dark.png
 FL-T200 Fuel Tank Small 275
(183.2) 		1.125 0.125 2 000 6 50 90 110
FL-T400 Dark.png
 FL-T400 Fuel Tank Small 500
(316.4) 		2.25 0.25 2 000 6 50 180 220
FL-T800 Dark.png
 FL-T800 Fuel Tank Small 800
(432.8) 		4.5 0.5 2 000 6 50 360 440
X200-8 White.png
 Rockomax X200-8 Fuel Tank Large 800
(432.8) 		4.5 0.5 2 000 6 50 360 440
X200-16 White.png
 Rockomax X200-16 Fuel Tank Large 1 550
(815.6) 		9 1 2 000 6 50 720 880
X200-32 White.png
 Rockomax X200-32 Fuel Tank Large 3 000
(1 531.2) 		18 2 2 000 6 50 1 440 1 760
Jumbo-64 White.png
 Rockomax Jumbo-64 Fuel Tank Large 5 750
(2 812.4) 		36 4 2 000 6 50 2 880 3 520
Kerbodyne S3-3600 Tank.png
 Kerbodyne S3-3600 Tank Extra large 3 250
(1 597.6) 		20.25 2.25 2 000 6 50 1 620 1 980
Kerbodyne S3-7200 Tank.png
 Kerbodyne S3-7200 Tank Extra large 6 500
(3 195.2) 		40.5 4.5 2 000 6 50 3 240 3 960
Kerbodyne S3-14400 Tank.png
 Kerbodyne S3-14400 Tank Extra large 13 000
(6 390.4) 		81 9 2 000 6 50 6 480 7 920
Mk2 LF+O Fuselage Short.png
 Mk2 Rocket Fuel Fuselage Short Mk2 750
(566.4) 		2.29 0.29 2 500 50 50 180 220
Mk2 LF+O Fuselage.png
 Mk2 Rocket Fuel Fuselage Mk2 1 450
(1 082.8) 		4.57 0.57 2 500 50 50 360 440
Mk3 Rocket Fuel Fuselage Short.png
 Mk3 Rocket Fuel Fuselage Short Mk3 2 500
(1 352.5) 		14.29 1.79 2 700 50 50 1 125 1 375
Mk3 Rocket Fuel Fuselage.png
 Mk3 Rocket Fuel Fuselage Mk3 5 000
(2 705) 		28.57 3.57 2 700 50 50 2 250 2 750
Mk3 Rocket Fuel Fuselage Long.png
 Mk3 Rocket Fuel Fuselage Long Mk3 10 000
(5 410) 		57.14 7.14 2 700 50 50 4 500 5 500
C7 Brand Adapter - 2.5m to 1.25m.png
 C7 Brand Adapter - 2.5m to 1.25m Small, Large 800
(433.0) 		4.57 0.57 2 300 20 50 360 440
C7 Brand Adapter Slanted - 2.5m to 1.25m.png
 C7 Brand Adapter Slanted - 2.5m to 1.25m Small, Large 800
(433.0) 		4.57 0.57 2 300 20 50 360 440
Mk2 to 1.25m Adapter.png
 Mk2 to 1.25m Adapter Small, Mk2 550
(366.4) 		2.29 0.29 2 500 50 50 180 220
Mk2 to 1.25m Adapter Long.png
 Mk2 to 1.25m Adapter Long Small, Mk2 1 050
(682.8) 		4.57 0.57 2 500 50 50 360 440
Mk2 Bicoupler.png
 Mk2 Bicoupler Small, Mk2 x 2 860
(676.4) 		2.29 0.29 2 500 50 50 180 220
2.5m to Mk2 Adapter.png
 2.5m to Mk2 Adapter Large, Mk2 800
(432.8) 		4.57 0.57 2 500 50 50 360 440
Mk3 to Mk2 Adapter.png
 Mk3 to Mk2 Adapter Mk2, Mk3 2 200
(1 282.0) 		11.43 1.43 2 600 50 50 900 1 100
Mk3 to 2.5m Adapter.png
 Mk3 to 2.5m Adapter Large, Mk3 2 500
(1 353.0) 		14.29 1.79 2 600 50 50 1 125 1 375
Mk3 to 2.5m Adapter Slanted.png
 Mk3 to 2.5m Adapter Slanted Large, Mk3 2 500
(1 353.0) 		14.29 1.79 2 600 50 50 1 125 1 375
Mk3 to 3.75m Adapter.png
 Mk3 to 3.75m Adapter Extra large, Mk3 2 500
(1 353.0) 		14.29 1.79 2 600 50 50 1 125 1 375
ADTP-2-3 Gray.png
 Kerbodyne ADTP-2-3 Large, Extra large 1 623
(246.0) 		16.88 1.88 2 000 6 50 1 350 1 650

RCS thrusters

RCS thrusters use their own fuel, monopropellant (except of the liquid fuel - oxidizer consuming Vernor Engine), and do not require a separate oxidizer. RCS is primarily used for steering a craft or making very small positional adjustments during docking; it is too weak and inefficient to function as a main maneuvering engine.

Advantages

Disadvantages

  • Very low thrust. The available RCS thrusters are too weak to lift off from most celestial bodies.
  • No thrust vectoring is available (however, the most commonly use thruster, the RV-105 RCS Thruster Block, can thrust in 4 directions).
  • The user can only switch engines on or off, while the SAS can run them on different thrust levels in between.
  • Low efficiency.
Available RCS engines
Image Part Radial size Cost
(Funds)		 Mass
(t)		 Max. Temp.
(K)		 Tolerance
(m/s)		 Tolerance
(g) 		Thrust
(kN) 		Fuel
(Units of fuel/s) 		Isp (s) (atm) Isp (s) (vac)
RV-1X.png
 RV-1X Variable Thruster Block Radial mounted 30 0.005 1 500 12 50 0.1 0.01 100 240
PlaceAnywhere1.png
 Place Anywhere 1 Linear RCS Port Radial mounted 15 0.001 1 500 12 50 0.2 0.02 100 240
RV-105.png
 RV-105 RCS Thruster Block Radial mounted 45 0.04 1 500 15 50 1.0 0.11 100 240
Linear RCS.png
 Place-Anywhere 7 Linear RCS Port Radial mounted 25 0.02 2 600 15 50 2.0 0.21 100 240
Vernor.png
 Vernor Engine[Note 1] Radial mounted 150 0.08 2 000 15 50 12.0 0.94 140 260
  1. ↑ The Vernor Engine uses a liquid fuel/oxidizer mixture.
Available monopropellant tanks
RCS Fuel Density is 4 kg/unit Mass
(t) 		Monopropellant
(Units of fuel)
Image Part Radial size Cost
(Funds)		 Full Empty Max. Temp.
(K)		 Tolerance
(m/s)		 Tolerance
(g)
FL-R10.png
 FL-R20 RCS Fuel Tank Tiny 200
(176) 		0.10 0.02 2 000 12 50 20
FL-R25 FT.png
 FL-R120 RCS Fuel Tank Small 330
(186) 		0.56 0.08 2 000 12 50 120
FL-R1 Yellow.png
 FL-R750 RCS Fuel Tank Large 1 800
(900) 		3.4 0.4 2 000 12 50 750
Mk2 Monopropellant Tank.png
 Mk2 Monopropellant Tank Mk2 750
(270) 		1.89 0.29 2 500 50 50 400
Mk3 Monopropellant Tank.png
 Mk3 Monopropellant Tank Mk3 5 040
(2 520) 		9.8 1.4 2 700 50 50 2 100
Stratus-v roundified monopropellant tank.png
 Stratus-V Roundified Monopropellant Tank X 200
(176) 		0.10 0.02 2 000 12 50 20
Stratus-V Cylindrified.png
 Stratus-V Cylindrified Monopropellant Tank X 250
(190) 		0.23 0.03 2 000 12 50 50

Ion engines

An ion engine uses electricity to ionize atoms of xenon gas and accelerate them in an electrostatic or electromagnetic field to propel them as exhaust. Remarkably little xenon gas fuel is needed, but ion engines are very demanding on electrical generation and storage.

Advantages

  • Extremely high efficiency, which is unaffected by atmosphere.

Disadvantages

  • Extremely low thrust. Ion engines cannot be used to lift off from most celestial bodies, and most maneuvers will take tens of minutes to complete.
  • High electric consumption.
  • No thrust vectoring currently available.
Available ion engines
Thrust
(kN) 		TWR Isp (s) Max. Consumption
Image Part Radial size Cost
(Funds)		 Mass
(t)		 Max. Temp.
(K)		 Tolerance
(m/s)		 Tolerance
(g) 		atm vac atm vac atm vac Electricity
(⚡/s) 		Xenon
(Xenon unit/s)
PB-ION.png
 IX-6315 "Dawn" Electric Propulsion System Tiny 8 000 0.25 2 000 7 50 0.048 2.0 0.019 0.816 100 4 200 8.741 0.486

Jet engines

Unlike rocket engines, jets propels the intake air (mainly), and draws oxygen from the atmosphere rather than taking it from an on-board tank. This is represented in-game by a much lower rate of fuel consumption. As they do so the classical rocket equation doesn't valid for them, and also they depends on the properly dense atmosphere consisting the vital oxygen.

Advantages

  • Provides excellent fuel efficiency within an atmosphere
  • All current jet engines provide thrust vectoring for greater maneuverability
  • Excellent power to weight ratio

Disadvantages

  • Cannot be used outside of an atmosphere that contains oxygen. In current version, it means they only function on Kerbin and Laythe.
  • Thrust output changes depending on speed
  • Engine requires time to spool up to maximum thrust potential
Available jet engines
Image Part Radial size Cost
(Funds)		 Mass
(t)		 Max. Temp.
(K)		 Tolerance
(m/s)		 Tolerance
(g) 		Thrust
(kN) 		TWR Fuel
(Units of fuel/s) 		Intake
(Air unit/s) 		Isp (s) TVC
(°) 		Reverse
J90JunoBasicJetEngine.png
 J-20 "Juno" Basic Jet Engine Tiny 450 0.25 2 000 7 50 20.0 Mach 0
20.6 Mach 1.3 		8.16 Mach 0
8.40 Mach 1.3 		0.064 1.402 6 400 — No
J33WheesleyBasicJetEngine.png
 J-33 "Wheesley" Turbofan Engine Small 1 400 1.5 2 000 7 50 120.0 Mach 0 8.16 Mach 0 0.233 29.601 10 500 — Yes
J404PantherAfterburningTurbofan.png
 J-404 "Panther" Afterburning Turbofan Small 2 000 1.2 2 000 7 50 85.00 Mach 0
107.89 Mach 1.75 /
130.00 Mach 0
219.48 Mach 2.5 		7.22 Mach 0
9.17 Mach 1.75 /
11.05 Mach 0
18.65 Mach 2.5 		0.193 /
0.663 		7.705 /
7.954 		9 000 /
4 000 		10.0 No
JX4WhiplashTurboRamjetEngine.png
 J-X4 "Whiplash" Turbo Ramjet Engine Small 2 250 1.8 2 000 7 50 130.00 Mach 0
386.66 Mach 3.0 		7.36 Mach 0
21.90 Mach 3.0 		0.663 5.303 4 000 1.0 No
J-90 Goliath Turbofan Engine.png
 J-90 "Goliath" Turbofan Engine Radial mounted 2 600 4.5 2 000 7 50 360.0 Mach 0 8.16 Mach 0 0.583 132.273 12 600 — Yes
Rapier Engine 01.png
 CR-7 R.A.P.I.E.R. Engine[Note 1] Small 6 000 2.0 2 000 20 50 105.00 Mach 0
465.64 Mach 3.75 		5.35 Mach 0
23.74 Mach 3.75 		0.669 4.015 3 200 3.0 No
  1. ↑ The R.A.P.I.E.R. Engine is a combination of liquid fuel and jet engine. Only the jet engine properties are shown.

See also

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