Atomic Warhead

One of several standard types of warheads, used commonly throughout Human Space. Each atomic/nuclear warhead is essentially an atomic or nuclear bomb fitted into the missile warhead, made to detonate on contact with enemy. The exact strength of it varies between missile types.
For conventional missiles it is rarely more than 10 to 20 kilotonnes. Light Shipkiller missiles normally have up to five megatonnes. Shipkiller missiles have 25 to 50 megatonnes typically.
With recent progresses in terms of ship defenses and, especially, hull integrity plus armour strength, capital ships can survive even direct hit from a shipkiller missile. Escort Ships will survive a Light Shipkiller missile, and various light units (frigates, in most cases) will survive a conventional missile hit. Each of them will, however, suffer a grievous damages and lose a lot of its external equipment.
Because of that, missiles with atomic warheads are used en masse, against a limited number of targets, hoping to overwhelm their defences and obliterate them with dozen detonations at once. To some successes.