Spaceflight Simulator Wiki
For the Side Separator variant, see Separator (Side)

Separators are five parts that can be used to separate stages from one another vertically. The differences between the five are their size, mass and separation force.

Separators must be adjacent to anything connected to their underside or sides (which will also drop away with them). Their top side can be used in the same way (but detaching from everything connected on activation), but can be connected to fuel tanks, separators, probes, capsules and capsules with space between them. This space has non-collidable fairings that can house parts aerodynamically, but won't prevent them from falling out.

When attaching to a part by this method, they have the same width adaptation range as fuel tanks have to each other, but 6-wide separators are the widest that can adapt to parachutes or two wide parts, not 8. 4-wide ones can connect to fuel tanks with up to 8 squares between them, 6-wide up to 9, 8-wide up to 10, 10-wide up to 11 and 12-wide up to 12.

It is usually placed between stages, usually with an engine on top and a fuel tank beneath. When the stage below runs out of fuel, it can be decoupled to decrease the remaining vehicle's mass. After detachment, the whole separator remains on the lower stage.

Side Separators can be used to separate SRBs, though vertical ones can be rotated 90º to fulfill the same function (less aerodynamically, but with more force, for instance to clear the boosters from colliding with lower protrusions).


  • Rocket scientists know of separators as stack separators.
  • The empty space between a separator and another stage is called an interstage.
Basics ParachuteCapsuleHawk EngineValiant EngineKolibri EngineFuel TanksSeparatorSide SeparatorAerodynamic Nose ConeLanding Leg
6 Wide 6 Wide Aerodynamic Nose ConeFuel TanksTitan EngineSeparator
8 Wide 8 Wide Aerodynamic Nose ConeFuel TanksSeparator
10 Wide Fuel TanksSeparator
12 Wide Fuel TanksSeparator
Engines Hawk EngineValiant EngineKolibri EngineTitan EngineFrontier EngineRCS ThrustersIon Engine
Aerodynamic Parts ParachuteSide ParachuteAerodynamic Nose ConeAerodynamic Fuselage
Fairings Fairing
Structural Structural Part
Other Docking PortLanding LegsIon EngineProbeRCS ThrustersRover WheelsSolar Panel
Currently discontinued in Version 1.5
BatteryRadioisotope Thermoelectric Generator