The Shiva-class Nuclear Missile is a starship and starfighter-launched thermonuclear weapon used by the United Nations Space Command. The Shiva can be outfitted with various payloads and explosive yields. These missiles are often employed by the UNSC in ship-to-ship engagements with the Covenant. UNSC forces only use nuclear weapons, such as the Shiva, when human forces are severely outnumbered, and/or tactical situations that demand the use of such weapons.