when to fairings lose their mass?

[Brainlord Mesomorph]

Fairings have mass. Does the ship lose the mass when you pop the fairing? or when you jettison the disk? 

I have an interplanetary payload in a fairing. I can't jettison the disk before I get there.  So should I pop the fairing before I leave? (to save weight)  or won't it matter in the game engine?

Edited May 17, 2016 by Brainlord Mesomorph

[Shadowmage]

The fairings lose mass for the panels the moment the panels are jettisoned.  This is a separate mass than for the fairing base -- that mass will only go away when the base is jettisoned.

So.. pop the panels as early as you can; generally this happens during the final stages of ascent, usually >40k meters is a good height for the stock atmosphere (below that there may be too much heating/drag; above that and you are wasting dV due to the panels mass).  The exact altitude will vary per-rocket/ascent-profile; generally when the flames start subsiding you are safe to jettison the panels.

[Claw]

9 hours ago, Brainlord Mesomorph said:

Does the ship lose the mass when you pop the fairing? or when you jettison the disk?

Technically it's both. The fairing panels have mass, but so does the base. The amount of mass in the fairing panels will vary by size, but the base is a lower (fixed) mass.