Tweakables are a system added in version 0.23 to set specific properties while in the Vehicle Assembly Building or Space Plane Hangar prior to launch. The major advantage is that these properties are stored with the craft scheme in the building, so they stay the same for every launch.
The following properties are changeable while building:
- The percentage of thrust an engine can use (Thrust Limiter).
- Resource levels of parts which contain them (i.e. liquid fuel tanks), in multiples of 10% of total capacity.
- Color of active lights (RGB)
- Whether landing gear begin deployed or retracted when launched.
- Whether landing gear or wheels can be steered.
- Whether steerable landing gear or wheels use inverted steering.
- Altitude at which parachutes fully deploy and minimum air pressure to fully deploy (seen in picture).
- Whether control surfaces and pivoting winglets are active in pitch, yaw, or roll commands.
- Whether a flag decal is displayed on parts which support them (i.e. command pods).