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).
- Color of active lights (RGB)
- Whether landing gear begin deployed or retracted when launched.
- Whether certain landing gear can be steered.
- Various deployment parameters of parachutes (seen in picture).
- Resource levels of parts which contain them (i.e. liquid fuel tanks), in multiples of 10% of total capacity.
- Whether a flag decal is displayed on parts which support them (i.e. command pods).