Operation: SILENT STORM was a UNSC operation to use EVA tactics to infiltrate Covenant vessels and either capture or destroy them from within early in the Human-Covenant War in March and April 2526. The operation consisted of a team of ODSTs known as the Black Daggers, and twelve Spartan-IIs, including John-117 and Blue Team. The operation was modeled after the actions taken during the Battle of Chi Ceti, where Spartan-IIs went EVA from a Pelican dropship and successfully boarded the Unrelenting, detonating a nuclear warhead from within the vessel, destroying it.
The operation was successful, though insurrectionist spies within the UNSC leaked their plan to the Covenant before it could be executed. Operational resources were redirected toward a Covenant resupply facility, and despite the attempts of insurrectionists to foil the plan, Blue Team was able to destroy the entire facility.
These events are depicted in the novel Halo: Silent Storm.