Every engine and thruster you can bolt to a rocket, from a first stage to a cold-gas block, and its figures from the info card.
An engine's thrust is quoted as a range, sea level to vacuum: the same flow makes less push at the pad than it does with nothing behind the nozzle. Read Air, heat and speed for why, Flying for the throttle and ignition, and Staging for lighting one from the staging list.
Engine
Part · Engines · sold by Rocketry
The rocket's first engine, and the one most first stages use: a middling thrust that lifts a stack off the pad before anything fancier is needed.
Figure
Value
MASS
600 kg
COST
200 cr
CONSUMES OXYGEN
9.06 u/s
CONSUMES METHANE
6.04 u/s
PRODUCES ELECTRICITY
0.02 u/s
THRUST
215 – 250 kN
ISP
290 – 338 s
QUOTED
SEA LEVEL – VACUUM
PROPELLANT
METHALOX
GIMBAL
±3°
DRAG NOSE-ON
1.0× (blunt)
MAX TEMP
2600 K
MAX G
30 g
IMPACT
14 m/s
BLAST
60 kN
NODES
2
STAGEABLE
YES
It attaches under a tank, and takes a separator or decoupler at its own base for the stage below it to fall away from.
Tap it, or its sheet, for Ignite or Shut down, worded by whether it is burning. Its properties sheet carries a Max power slider and an RCS control toggle, both usable in flight.
Pairs with a Fuel Tank above it. Instead of it, the Vacuum Engine trades sea-level thrust for a much better burn once you are above the air.
Vacuum Engine
Part · Engines · sold by Vacuum Engines
A wide vacuum bell: weak at the pad, but it turns the same flow into far more thrust once the air behind the nozzle is gone. Fly it on an upper stage, never a first one.
Figure
Value
MASS
560 kg
COST
450 cr
CONSUMES OXYGEN
4.37 u/s
CONSUMES METHANE
2.91 u/s
PRODUCES ELECTRICITY
0.02 u/s
THRUST
60 – 150 kN
ISP
168 – 420 s
QUOTED
SEA LEVEL – VACUUM
PROPELLANT
METHALOX
GIMBAL
±4°
DRAG NOSE-ON
1.0× (blunt)
MAX TEMP
2600 K
MAX G
25 g
IMPACT
12 m/s
BLAST
60 kN
NODES
2
STAGEABLE
YES
It attaches under a tank, and takes a separator or decoupler at its own base for the stage below it to fall away from.
Tap it, or its sheet, for Ignite or Shut down. Its properties sheet carries a Max power slider and an RCS control toggle, both usable in flight.
Pairs with a stage that lights above the atmosphere. Instead of it, the plain Engine works at the pad, where a vacuum bell over-expands and loses thrust.
Solid Booster
Part · Engines · sold by Solid Boosters
A case of propellant with the nozzle cast into its base: light it and it burns flat out until the grain is spent, with no shutdown and no throttle.
Figure
Value
DRY MASS
350 kg
FULL MASS
2078 kg
COST
180 cr
STORES SOLID_FUEL
144 u · 1728 kg
CONSUMES SOLID_FUEL
2.4 u/s
THRUST
67 – 76 kN
ISP
237 – 269 s
QUOTED
SEA LEVEL – VACUUM
PROPELLANT
SOLID
DRAG NOSE-ON
1.0× (blunt)
HEAT EXPOSURE
1.3×
BODY LIFT CL
0.25
MAX TEMP
2400 K
MAX G
100 g
IMPACT
14 m/s
BLAST
200 kN
NODES
3
STAGEABLE
YES
BURN TIME
60 s
THROTTLES
NO
It stacks like a tank on top, and straps to the flank of another stage on the rails down its sides, the way a decoupler lets it fall away.
Note
Whatever length you cast it at, one Solid Booster always empties its case in the same 60 s. Only its Burn rate property, not its length, trades that push for how long it lasts.
Tap it, or its sheet, for Ignite; there is no Shut down once it is lit. Its properties sheet carries a Length slider and a Burn rate slider (50–100–150%), both hangar only.
Pairs with an Engine as strap-on boosters off the pad. Instead of it, an Engine of your own gives you a throttle and a shutdown, at more mass for the same push.
Solid Booster S
Part · Engines · sold by Solid Boosters
The Solid Booster's smaller sibling: less push and less propellant, for a stage that only needs a kick.
Figure
Value
DRY MASS
175 kg
FULL MASS
1039 kg
COST
95 cr
STORES SOLID_FUEL
72 u · 864 kg
CONSUMES SOLID_FUEL
1.2 u/s
THRUST
34 – 38 kN
ISP
241 – 269 s
QUOTED
SEA LEVEL – VACUUM
PROPELLANT
SOLID
DRAG NOSE-ON
1.0× (blunt)
HEAT EXPOSURE
1.3×
BODY LIFT CL
0.25
MAX TEMP
2400 K
MAX G
100 g
IMPACT
14 m/s
BLAST
120 kN
NODES
3
STAGEABLE
YES
BURN TIME
60 s
THROTTLES
NO
It stacks like a tank on top, and straps to the flank of another stage on the rails down its sides, the way a decoupler lets it fall away.
Tap it, or its sheet, for Ignite; there is no Shut down once it is lit. Its properties sheet carries a Length slider and a Burn rate slider (50–100–150%), both hangar only.
Pairs with a light stage, or a pair mirrored either side of it. Instead of it, the full-size Solid Booster carries a longer burn on the same rails.
RCS Thruster Block
Part · Engines · sold by Attitude Control
A block of four cold-gas nozzles: it answers your turn and slide commands directly, firing only the nozzles whose geometry actually turns or slides the ship.
Figure
Value
MASS
40 kg
COST
120 cr
CONSUMES HYPERGOLIC
0.07 u/s
DRAG NOSE-ON
0.9×
HEAT EXPOSURE
0.9×
MAX TEMP
3400 K
MAX G
20 g
IMPACT
10 m/s
BLAST
4 kN
NODES
1
NOZZLES
4
THRUST / NOZZLE
1.5 kN
GAS / NOZZLE
0.54 kg/s
ISP
281 s
It bolts to a single point on a flank, wherever the ship needs a push, on a mount that carries hypergolic propellant.
It has no actions to tap. Its only property is a Thrusters toggle, usable in flight, so you can switch that one block off without cutting the whole RCS system.
Pairs with a Hypergolic Sphere or Pod on the same flank. Instead of one, wire an engine's RCS control toggle for a single strong nozzle rather than four small ones.
Heavy Engine
Part · Engines · sold by Heavy Engines
The biggest throttled engine in the palette: built for a stage too heavy for the plain Engine to lift.
Figure
Value
MASS
1700 kg
COST
900 cr
CONSUMES OXYGEN
39.32 u/s
CONSUMES METHANE
26.21 u/s
PRODUCES ELECTRICITY
0.06 u/s
THRUST
900 – 1000 kN
ISP
280 – 311 s
QUOTED
SEA LEVEL – VACUUM
PROPELLANT
METHALOX
GIMBAL
±5°
DRAG NOSE-ON
1.0× (blunt)
MAX TEMP
2600 K
MAX G
28 g
IMPACT
14 m/s
BLAST
200 kN
NODES
2
STAGEABLE
YES
It attaches under a tank, and takes a separator or decoupler at its own base for the stage below it to fall away from.
Tap it, or its sheet, for Ignite or Shut down. Its properties sheet carries a Max power slider and an RCS control toggle, both usable in flight.
Pairs with the largest tanks for a heavy first stage. Instead of it, a cluster of plain Engines spreads the same thrust over more mounting points.
Lander Engine
Part · Engines · sold by Lander Engines
A small throttled engine tuned for gentle burns: light enough for a lander stage, with the finest gimbal of the throttled engines for careful landings.
Figure
Value
MASS
70 kg
COST
90 cr
CONSUMES OXYGEN
0.61 u/s
CONSUMES METHANE
0.41 u/s
PRODUCES ELECTRICITY
0.01 u/s
THRUST
12 – 20 kN
ISP
240 – 400 s
QUOTED
SEA LEVEL – VACUUM
PROPELLANT
METHALOX
GIMBAL
±6°
DRAG NOSE-ON
1.0× (blunt)
MAX TEMP
2600 K
MAX G
25 g
IMPACT
12 m/s
BLAST
12 kN
NODES
2
STAGEABLE
YES
It attaches under a tank, and takes a separator or decoupler at its own base for the stage below it to fall away from.
Tap it, or its sheet, for Ignite or Shut down. Its properties sheet carries a Max power slider and an RCS control toggle, both usable in flight.
Pairs with a lander stage over the Moon or Mars. Instead of it, the Vacuum Engine pushes harder for the same weight class when you don't need as fine a touch.
Escape Motor
Part · Engines · sold by Escape Motors
A hypergolic torch bolted to a capsule's flank: enormous thrust for a few seconds, enough to throw a crew clear and nowhere near enough to fly anywhere on.
Figure
Value
MASS
120 kg
COST
290 cr
CONSUMES HYPERGOLIC
5.43 u/s
PRODUCES ELECTRICITY
0.02 u/s
THRUST
115 – 130 kN
ISP
270 – 305 s
QUOTED
SEA LEVEL – VACUUM
PROPELLANT
HYPERGOLIC
GIMBAL
±12°
DRAG NOSE-ON
0.85×
HEAT EXPOSURE
0.85×
MAX TEMP
2600 K
MAX G
25 g
IMPACT
12 m/s
BLAST
30 kN
NODES
1
STAGEABLE
YES
Its one attachment point is on its side, so it mounts radially and its bell points down the vessel's axis wherever you stick it. Mirror a second one on the opposite flank.
Note
Its 5.43 u/s draw empties a full HT-2 Hypergolic Tank in about seven seconds. It is built to fire once, not to fly on.
Tap it, or its sheet, for Ignite or Shut down. Its properties sheet carries a Max power slider and an RCS control toggle, both usable in flight, like any throttled engine.
Pairs with a Crew Capsule and a Hypergolic Tank on the same flank for an abort system. Instead of it, nothing else in the catalog is built for the same job.
Separation Motor
Part · Engines · sold by Radial Staging
A thumb-sized solid cluster bolted to a booster's flank, whose whole job is one second of shove the moment the booster lets go, so the spent case leaves the stack instead of drifting back into it.
Figure
Value
DRY MASS
10 kg
FULL MASS
11 kg
COST
12 cr
KICK
3 – 3.4 kN
ISP
240 – 272 s
BURN TIME
1.0 s
NOZZLES
2
THROTTLES
NO
STORES SOLID_FUEL
0.11 u · 1 kg
CONSUMES SOLID_FUEL
0.11 u/s
DRAG NOSE-ON
0.9×
HEAT EXPOSURE
0.9×
MAX TEMP
2400 K
MAX G
100 g
IMPACT
12 m/s
BLAST
6 kN
KICK CANT
60°
NODES
1
STAGEABLE
YES
Its one attachment point is on its side, so it mounts on any rail. Its two nozzles, one at each end, are turned 60° in toward whatever it is bolted to, so their jets play across its skin and the push goes the other way: straight out from the mount. Where it sits on the rail decides the rest. Level with the booster's middle it is a clean sideways shove; high on the case it also swings the booster's nose out. Mirror a second one on the other booster; the mirror turns its nozzles the other way for you.
Note
It is not counted as thrust. The hangar's Δv and TWR figures, the fuel ring and the flight's idea of whether you are burning all leave it out: a kick is not a burn. Its 3 kN for one second gives an empty Solid Booster S about 18 m/s sideways and the full-size Solid Booster about 9 m/s, several times what a Decoupler alone gives it; drag in thick air takes some of that back.
Tap it, or its sheet, for Fire; there is no Shut down once it is lit, and on the pad the tap does nothing. It has no properties sheet to edit. Put it in the same stage as the booster's Decoupler and it lights first, so the booster leaves already pushing.
Pairs with a Solid Booster or Solid Booster S on a Decoupler. Instead of it, nothing else in the catalog is built for the same job; a Decoupler alone gives a gentler push. Throw a booster clear has the steps.
