Spaceflight Simulator Wiki
Part category 6.png
Parts Expansion Required
Some or all of the parts and/or features on this page require the Parts Expansion in-app purchase.

Engines are vital parts in any successful rocket. They provide continuous propulsion to drive rockets to their destination.

In Spaceflight Simulator, there are seven liquid-fueled engines, a reaction control system and two solid rocket boosters. Currently, all of the engines consume fuel to run. The ion engine is formerly required to consume both fuel and electricity, but the electricity rework disabled this feature. Solid rocket boosters have their own integrated solid fuel tanks.

Types of engines

There are seven liquid fueled engines in the game. They are named Titan, Hawk, Peregrine, Frontier, Valiant, Kolibri and Ion. The odd one is the RCS Thruster; its name doesn't end with "Engine", but "Thruster", unlike the other six do. The engine thrusts on 4 vectors, unlike other engines, which expel fuel out of the nozzle, and the ion engine, that do some process to expel the fuel out.

Here are the types of engines:

Liquid-Fueled Engines
Name Appearance Mass Thrust Efficiency (Isp) Description
Titan Engine
12 tons 400 tons 240s The biggest and engine in the game. The engine has very high thrust, but it has a low efficiency, so it is used usually in first stages of rockets, where the atmosphere is thicker, and to lift off the whole rocket and push it into orbit around the Earth. The engine can be also used for solid rocket boosters. It is the larger variant of the Hawk Engine.

This engine uses kerolox (kerosene and liquid oxygen) for fuel, that's why it burns out an opaque orange plume.

Hawk Engine
3.5 tons 120 tons 240s The largest basic engine in the game. This engine has high thrust, but lower efficiency, as it can be used in first stages of rockets and solid rocket boosters. The engine weighs very light, at 3.5 tons, much lighter than the Titan engine.

This engine uses kerolox (kerosene and liquid oxygen) for fuel, that's why it burns out an opaque orange plume.

Peregrine Engine
2 tons 75 tons 180s A basic engine that is only available for Career Mode and can be used for lower stages of a rocket. It has very low efficiency, but medium thrust. It is the first liquid fueled engine player unlocks in Career.

This engine likely uses kerolox (kerosene and liquid oxygen) for fuel, that's why it burns out an opaque orange plume.

Frontier Engine
6 tons 100 tons 290s A large engine, that formerly only could fit on a 6 wide fuel tank, has very high efficiency and high thrust, so it is used on upper stages of rockets. It works well in a vacuum unlike the Titan and Hawk Engine, which are the most efficient in atmospheres. The engine works best when used for long interplanetary transfers, because efficient engines have low fuel consumption.

This engine uses hydrolox (liquid hydrogen and liquid oxygen) for fuel, that's why it burns out a blue plume with a visible shock diamond.

Valiant Engine
2 tons 40 tons 280s A basic engine that can be used for upper stages of a rocket. They have high efficiency, but low thrust. They can also used as landing engines, due to their high efficiency and low thrust. merging a lot of engines would recreate the real life Raptor engine.

This engine uses methalox or hydrolox (liquid methane and liquid oxygen or liquid hydrogen and liquid oxygen) for fuel, that's why it burns out a purple-pink plume.

Kolibri Engine
0.5 tons 15 tons 260s This engine is small, but terrible.

This engine has moderately-high efficiency, but low thrust of only 15 tons.

The engine can be used as a landing engine on the Moon, Phobos and Deimos due to its extremely low thrust.

This engine uses methalox or hydrolox (liquid methane and liquid oxygen or liquid hydrogen and liquid oxygen) for fuel, that's why it burns out a purple-pink plume.

Ion Engine
Screenshot 20200609-113643.png
0.5 tons 1.5 tons 1200s The engine, along with the RCS Thruster, are the smallest engines in the game, only occupying a 2×1 array of tiles.This engine is also the lightest of all engines in the game. The engine can be used on satellites and orbiters due to its extremely low thrust, to change their trajectory. The engine has very low thrust, but VERY HIGH efficiency at 1200s. This engine cannot work well on thick atmospheres due to its very low thrust.

It can be used as landing engines, for long interplanetary transfers and a replacement for RCS.

This engine uses xenon or krypton fuel.

RCS Thruster
0.05 tons 1.5 tons 120s The least efficient liquid fueled engine in game. This engine can be used for orbital maneuvering but not for rocket engines at launch of the rocket.

It fires on 4 vectors, but appears to be 3 because the game is 2 dimensional.

The engine can be place on upper stages of the rocket.

The engine uses all fuel, unlike all other engines in the game.


They are very important parts of the rocket. Engines are used to launch rockets, correct trajectories, transfer burns and many more.

How engines work?

There are mainly two types of engines, liquid fuel engines and solid fuel engines and they work differently.

Solid fuel engine

There are two types of solid fuel engines in game, but as of beta they are exactly like Peregrine Engine available only in Career Mode. As of January 29, 2022, they both have the same in-game name, but in blueprints they are named Booster Tut 1 and Booster Tut 3. They have lowest efficiency of all the engines with Isp of only 60 seconds.

Solid rocket engines are used on air-to-air and air-to-ground missiles, on model rockets, and as boosters for satellite launchers. In a solid rocket, the fuel and oxidizer are mixed together into a solid propellant which is packed into a solid cylinder. A hole through the cylinder serves as a combustion chamber. When the mixture is ignited, combustion takes place on the surface of the propellant. A flame front is generated which burns into the mixture. The combustion produces great amounts of exhaust gas at high temperature and pressure. The amount of exhaust gas that is produced depends on the area of the flame front and engine designers use a variety of hole shapes to control the change in thrust for a particular engine. The hot exhaust gas is passed through a nozzle which accelerates the flow. Thrust is then produced according to Newton's third law of motion. - from

Liquid fuel engine

There are, of course liquid fuel engines in the game. Four out of six engines are liquid fuel engines. They are:

  • Titan Engine
  • Hawk Engine
  • Frontier Engine
  • Valiant Engine
  • Kolibri Engine

This is how it works:

Liquid rocket engines are used on the Space Shuttle to place humans in orbit, on many un-manned missiles to place satellites in orbit, and on several high speed research aircraft following World War II. In a liquid rocket, stored fuel and stored oxidizer are pumped into a combustion chamber where they are mixed and burned. The combustion produces great amounts of exhaust gas at high temperature and pressure. The hot exhaust is compressed at the smallest point of the nozzle, making it reach supersonic speed. To accelerate further, the exhaust rushes into a widening nozzle. Thrust is produced according to Newton's third law of motion. This is very similar to when a balloon filled with air is let go. - from

Odd engines

The odd engines, RCS and Ion Engine work differently than solid or liquid fuel engines. They have some process of pumping fuel out of the tanks. Here is how they work:

RCS thrusters

Reaction control systems often use combinations of large and small (vernier) thrusters, to allow different levels of response. Spacecraft reaction control systems are used for:

  • attitude control during re-entry;

  • stationkeeping in orbit;

  • close maneuvering during docking procedures;

  • control of orientation, or 'pointing the nose' of the craft;

  • a backup means of deorbiting;

  • ullage motors to prime the fuel system for a main engine burn.

    Source from Wikipedia

Ion engines

An electrostatic ion engine works by ionizing a fuel (often xenon or argon gas) by knocking off an electron to make a positive ion. The positive ions then diffuse into a region between two charged grids that contain an electrostatic field. This accelerates the positive ions out of the engine and away from the spacecraft, thereby generating thrust. Finally, a neutralizer sprays electrons into the exhaust plume at a rate that keeps the spacecraft electrically neutral.

Source from,to%20make%20a%20positive%20ion.&text=Finally%2C%20an%20neutralizer%20sprays%20electrons,works%20by%20ionizing%20a%20fuel.


  • In 1.5.4, you cannot clip engines together. Stef said it's too unchallenging if you do this and he received tons of hate for removing that feature. However, he re-enabled it in, but engines now heat each other, causing them to explode.

Basics ParachuteCapsuleHeat ShieldSeparatorFuel TanksHawk EngineValiant EngineKolibri EnginePeregrine EngineRCS ThrustersSide SeparatorSolid Rocket BoostersAerodynamic Nose ConeLanding Leg
6 Wide 6 Wide Aerodynamic Nose ConeFuel TanksSeparatorHeat ShieldEngine Base
8 Wide 8 Wide Aerodynamic Nose ConeFuel TanksSeparatorHeat ShieldEngine Base
10 Wide Fuel TanksSeparatorHeat ShieldEngine Base
12 Wide Fuel TanksSeparatorHeat ShieldEngine Base
Engines Titan EngineFrontier EngineHawk EnginePeregrine EngineValiant EngineKolibri EngineRCS ThrustersIon Engine
Aerodynamic Parts ParachuteSide ParachuteAerodynamic Nose ConeAerodynamic Fuselage
Fairings Fairing
Structural Structural Part
Other Docking PortLanding LegsIon EngineProbeRCS ThrustersWheelsSolar PanelFuel Pipe
Currently removed in Version 1.5
Removed in older versions
Probe (Large)Fairing AdapterAdapter

All items (11)