Fail-safe detonation system

The MJOLNIR Powered Assault Armor is equipped with a fail-safe detonation system. If a Spartan is killed or wounded fatally, or they are forced to shed the armor in the field, the self-destruct protocol will have to be enacted by either themselves or a nearby Spartan. This is done to avoid capture of the suit and/or the wearer for identification or technological study.

Function
The tiny access panel at the back of the suit is opened to activate the protocol, it is activated by typing several digits only Spartans know. Once activated, a fifteen-second countdown timer starts. Once it hits zero, the suit's fusion reactor overloads and burns everything in its path in a ten-meter radius with a follow-up explosion to finish anything alive.

Uses

 * John-117 activated the fail-safe detonation system on Grace-093's suit after she was killed by a Brute in the Covenant resupply station Unyielding Hierophant.
 * Fred-104's damaged and inert CENTURION-class Mjolnir suit's fail-safe detonation system was activated at the conclusion of Operation: JOVIAN WHISTLE on Gao in order to prevent the armor from falling into enemy hands, destroying two low-flying Gao Wyverns in the process.

List of appearances

 * Halo: First Strike
 * Halo: Last Light