The auto-destruct system (also known as self-destruct or destruct sequence) is a starship system that allows the total destruction of the vessel. This is typically activated as a last resort, usually to prevent a ship from falling into enemy hands.
On Starfleet vessels, the activation sequence varies from class to class, but usually requires authorisation from the Captain and/or senior officers, with the use of command authorization codes in most cases. Once the countdown is activated, the computer gives audio warnings, usually with an interval of 10 seconds, and displays graphics on viewscreens.
On Constitution-class starships, three officers were required to initiate the destruct sequence, using the following, concurrent codes. Each would state name and rank, then the code:
- "Destruct Sequence One, Code 11A"
- "Destruct Sequence Two, Code 11A2B"
- "Destruct Sequence Three, Code 1B2B3"
The computer would then ask for the final code to commence countdown, given by the highest-ranking officer (usually the captain): "0-0-0-Destruct-0"
The default setting was for a one-minute countdown, but this could be altered during the sequence initiation. The sequence could be aborted at any time up until T-15 seconds by the captain or highest-ranking officer, with the code "Abort destruct sequence, code 1-2-3-Continuity". (Star Trek III: The Search for Spock)
On the Galaxy-class starship, the Captain and First Officer activated the destruct sequence from Main Engineering. Both would provide palmprint identification, and order the self destruct, both having to agree. This could be aborted from the Main Bridge. (TNG: "11001001")
The Defiant class sequence was activated from the Bridge, requiring two officers' consent, and handprint verification to activate and abort.
Aboard the Intrepid class, auto-destruct required the captain's sole authorization. This class had the option of ordering a silent countdown - a single voice prompt would occur at the commencement of the sequence, with no further audio warnings made.
The Sovereign class returned to the 'three-officer' authorisation method. Each would state name and rank, confirming the sequence, and giving their authorisation code. The senior officer would then select the destruct sequence type, sequence delay, and whether a silent countdown would be initiated. The sequence would begin upon use of the command "Enable". (Star Trek: First Contact)
- The self-destruct was authorised in Star Trek: Nemesis, but failed because the computer was offline. It appeared to have been changed, as Picard authorised the sequence by himself.
On most Federation ships, the destruct sequence used one of two methods of completion (both may be installed to allow for redundancy).
The first involves used the ship's matter and antimatter fuel supplies, combining them in an unmoderated reaction, the resultant annihilation reaction being more than enough to obliterate the entire vessel, much like a warp core breach. The second, explosive charges placed at key points throughout the vessel to ensure complete destruction.