A cruiser is a large type of warship, which had its prime period from the late 19th century to the end of the Cold War. The first cruisers were intended for individual raiding and protection missions on the seas. Over the years, the nature and role of the cruiser has changed considerably, and today the cruiser has largely been replaced by destroyers in its roles. A moden cruiser is a large warship capable of engaging multiple targets simultaneously. A cruiser is the smallest ocean-going warship capable of independent operations.
Cruisers were ships, often frigates or smaller vessels, which were assigned a role largely independent from the fleet. Typically this might involve missions such as raiding enemy merchant shipping. Other roles included reconnaissance, and cruisers were often attached to the battlefleet. In the late 20th century the role of the cruiser increasingly became one of providing air defense for a fleet, rather than independent cruiser warfare. At the beginning of the 21st century, cruisers were the heaviest surface combatant ships in use.
The cruiser replaced the fast frigate of the early U.S. Navy. During its evolution, it has served many roles; it has been used in commerce, raiding, communications control, screening, antiaircraft defense, escorting aircraft carriers, and supporting amphibious landings. Today, its mission is to destroy enemy surface ships, submarines, aircraft, and missiles. In addition to 5-in. guns, missiles such as Harpoon and Tomahawk, the Phalanx system, anti-submarine warfare helicopters, and torpedoes comprise some of the cruiser's firepower.
The Ticonderoga class of missile cruisers is a class of warships in the United States Navy. The Ticonderoga class are outfitted with two Vertical Launching Systems (or VLS). The two VLS allow the ship to have 122 launch tubes that can carry a wide variety of missiles, including the Tomahawk cruise missile, the Standard surface-to-air missile, the Evolved Sea Sparrow surface-to-air missile, and the ASROC anti-submarine missile. More importantly, the VLS enables all missiles to be on full stand-by at any given time, shortening the ship's response time.
Many cruisers now have the AEGIS surface-to-air missile system, a highly sophisticated and capable weapons system used by the United States Navy. It is both an integrated single ship system and a ship-to-ship network. The Aegis combat system is one of the most advanced and most capable defense systems currently in use. It is also used by the Japan Maritime Self-Defense Force, Spanish Navy, Royal Norwegian Navy, and Republic of Korea Navy.
The Aegis Combat System (ACS) is an advanced command and control, and Weapon Control System (WCS) that uses powerful computers and radars to track and guide weapons to destroy enemy targets. It is the world's most advanced naval surface ship combat system and the first fully integrated combat system built to defend against air, surface, and subsurface threats.
The computer-based command-and-decision element is the core of the Aegis Combat System. This interface makes the ACS capable of simultaneous operation against almost all kinds of threats. The Aegis Ballistic Missile Defense System program is intended to enable the Aegis system to act in a Sea-based Ballistic Missile Defense role, to counter short- and medium-range ballistic missiles of the variety typically employed by a number of potential opponent states.