Anaconda surface-to-air missile
From Halopedia, the Halo wiki
The Anaconda Surface to Air Missile is a type of anti aircraft ordinance used by the UNSC.
These missles are only mentioned once in the Halo series, during the book Halo: First Strike where the SPARTANS recover a crate marked HighCOM Armory Omega that contained six Anaconda STA missiles and a pair of Fury Tac nukes; the missiles were never used according to the book because the EMP from the nuclear detonations would blow the generators the Spartans were trying to protect.
