Can somebody please explain further. Given that 9.80665 is the local (acceleration due to) gravity for Kerbin, shouldn't delta-V change when you move into a different sphere of influence? Or is it implicit that delta-V is measured with respect to the gravity of our home planet? If that is the case, wouldn't inhabitants of other celestial bodies calculate different delta-V values for the same ship (even though using the same units of meters per second?)