Ablative armor was a type of protective hull plating used on starships, which possessed a capability for rapidly dissipating the energy impacts from directed energy weapon fire. Starfleet began use of ablative armor technology by 2371.

External Information

Ablative Armor at Memory Alpha

SECURITY AND TACTICAL DEPARTMENT
IMPORTANT ERRATA	Security and Tactical Department • Security and Tactical Positions • Search and Rescue Specialized Duty Posts • Security Clearances
TACTICAL SYSTEMS	Ablative Armor • MLSS Shields • Phaser Arrays • Photon Torpedoes • Quantum Torpedoes • Tri-Cobalt Torpedoes
SECURITY FUNCTIONS	Access Codes • Security Locations • Security Terminology • Starship Security Procedures Phaser Settings • Tactical Belt • Type-I Phaser • Type-I Non-Lethal Pistol • Type-II Phaser • Type-III Phaser
NOTABLE LOCATIONS	Security Complex • Chief Security Officer's Office • Brig • Isolation Cell • Armory • Phaser Range • Weapons Locker
PERSONNEL FUNCTIONS	Alert Status • Cabin Assignments • Computer Access Levels • Deck Listing • Department Head • Duty Roster • Operating Modes • Security Clearances • Rank Guide • Rank Comparisons • Uniforms
DEPARTMENTS	Command • Flight Control • Intelligence • Operations • Engineering Security/Tactical • Medical • Science • Squadron • Civilians