Ablative armor

Ablative armor hull plating was in development for a number of years prior to its deployment on the Defiant class in 2270. Various factors related to materials availability, instabilities, phaser and torpedo resistance, and long fabrication lead times prevented its widespread use on frontline starships, though it was later introduced on several other designs developed under the Perimeter Defense Directive. The armor worked in two stages; in the event of shield envelope disruption, phaser or thermal EM was first dissipated over the hull surface, and above an undisclosed threshold caused the molecular matrix to boil off at a controlled rate, carrying away a large fraction of the landed beam energy. In most cases, the boil-off created a medium density particle cloud, which could also help disperse an incoming beam.