Polarized hull plating

Polarized hull plating was an early form of protective armor used by 22nd century Earth Starfleet vessels. This type of armor was a precursor to the energy shielding used by federation ships in the 23rd century and operated by reversing the polarity of the ship’s hull to absorb energy rather than deflect it. Hull polarization was the most common form of shielding used by Earth Starfleet until after the Earth-Romulan War.