Fury tactical nuclear weapon

The Fury Tactical Nuclear Weapon is a weapon used by the United Nations Space Command.

Background
The Fury Tactical Nuclear Weapon (nicknamed Tac-Nuke by the UNSC) is a battlefield nuclear weapon used by the UNSC, and has been described as the closest equivalent in the UNSC arsenal to 'a nuclear grenade'. It is the size and shape of an over inflated football. Its yield has been stated to be slightly less than one megaton, and the nuclear blast has been described as extremely clean and has a radius of about 1.3 km. The Fury is relatively effective at destroying anything from a Covenant base to a Covenant Cruiser, although the Fury would have to be inserted prior to detonation.

Fall of Reach
During the attack on Reach, Spartans Frederic-104, Kelly-087, and Joshua-029 (AKA Red Team) destroyed a Covenant Cruiser by capturing a trio of Banshees and throwing a Fury into its Grav-lift during the Battle of Reach. The reason for this style of attack was due to the electromagnetic pulse (EMP) given off by the warhead. By throwing the Fury nuclear weapon into the gravity lift the Fury entered the Cruiser's hull. This tactic used the Covenant Cruiser's own shield to buffer most of the EMP and essentially prevented damage to the generators powering the MAC guns orbiting Reach. Another reason, for this tactic was that the Fury's explosion rebounded upon itself inside the cruiser absolutely gutting the cruiser and protecting the three Spartans flying away. Kelly-087 remarked that "It'll also turn that ship into the biggest fragmentation grenade in history,".

By destroying the Covenant Cruiser, they halted an initial invasion force, killing over ten thousand Covenant troops. This description reveals that the three Spartans kept the Covenant fleet from being able to reinforce Reach.