A fairing is a part that encapsulates other parts like a payload to shield them against aerodynamic stresses and heating. Fairings can also improve the aerodynamic shape, reducing drag and making the rocket more stable. After being deployed the fairing pieces are not considered debris, or objects that can be focused. Another use case is as an interstage fairing to reduce drag. Fairings don't provide structural integrity, although protecting elements from airflow can improve overall stability.
Fairings are a procedural part available in the stock game. They are built-in stacking sections, which can be angled, or snapped to vertical. If the diameter of a new section is small enough, the fairing will automatically close and add a cap. If the fairing is touching another circular part above the fairing base, it will close itself, creating an interstage fairing. In this case, the end of the fairing doesn't physically attach to the next part, and they can shift in relation to each other during flight.
While building a fairing, status text will show its mass and cost, and tell whether the next section will close the fairing. The text will be green if the current section is valid, and orange if it can't be created. Parts which clip through the fairing will show Mach effects, but won't apply drag and won't damage the fairing. The "clamshell" setting affects how the fairing is jettisoned: when enabled, the fairing will break into large slices, with the number of slices tweakable. When disabled, the fairings will explode into tiny pieces like confetti.
It is important to note that a fairing is not a decoupler nor a separator. If you are using a fairing to protect a payload, such as a satellite, you will still need to have a decoupler or separator to deploy the payload.
List of fairings
|Image||Part||Radial size|| Cost
| Max Radius
| Panel mass
| Panel Cost|
|AE-FF1 Airstream Protective Shell (1.25m)||Small||300||0.075||2 600||9||50||1.5||0.01||6|
|AE-FF2 Airstream Protective Shell (2.5m)||Large||600||0.175||2 600||9||50||3||0.012||12|
|AE-FF3 Airstream Protective Shell (3.75m)||Extra large||900||0.475||2 600||9||50||6||0.016||18|