Until the 1980s, most air defence missiles were fired from trainable launchers that were reloaded by complicated mechanical systems designed to fetch rounds from below-deck magazines. More recent systems have tended to use vertical launch systems for both area defence and shorter range surface-to-air missiles. Although the first CG-47 Aegis-class cruisers used trainable launchers, a switch was made to vertical launch at the earliest possible date.

Vertical launchers have fewer moving parts, and do not suffer from the blind arcs associated with trainable launchers. A single set of vertical launch silos can provide hemispherical 360-degree coverage. Since they do not need to be slewed to face the target, they can launch rounds more quickly, while the elimination of manual or mechanical loading speeds up the firing of salvoes. The Mk 48 VLS used with the Seasparrow requires the same space as a trainable launcher, but can hold up to 16 rounds, twice the number of ready-to-launch missiles.

Vertical launch systems can carry a much wider range of missile types than traditional launchers. Just as an aircraft carrier gains an increase in capability by deploying new types of aircraft, a vertical launch ship can be upgraded by adding new weapons to the launcher. By 2005, Aegis ships could be equipped with the SM-2 Block IVA, SM-2/Leap, and "four-pack" containers for the Evolved Seasparrow.

The red-coloured components within this cutaway launch/storage container are the ejection mechanism which catapults the 48N6E missile clear of the vertical launch cell of the Rif missile system (note: H = Cyrillic N).

Like any new development, vertical launch also introduces possible disadvantages. The flexibility of a vertical launcher means that not all the cells in the launcher may be available for defensive missiles. Competing with space in the launcher on Aegis ships will be other missiles such as vertical launch anti-ship missiles, several models of Tomahawk and a navalised version of the Army Tactical Missile System (Atacms).

Lowering a missile into the launch silo is not an easy task, and may only be possible at the dockside. The Mark 21 VLS launch canister for the SM-2 Block IV round and its variants, and the Mark 14 canister for the Tomahawk land attack missile (TLAM) are within a thousand pounds of each other, and cannot be transferred at sea. They are several thousand pounds too heavy for the existing handling crane. A US Navy warship that runs out of SM-2 Block IVA, SM-2/Leap and TLAM missiles in a future conflict will have to break off its patrol and proceed to port to reload. Getting replacement rounds to a suitable port could require an expensive and capacity-limited airlift operation (reload rounds for a single Aegis cruiser would require more than four C-5 Galaxy sorties), or the slower delivery of large numbers of missiles by sea.

In Fiscal Year 1996 the US Navy started work on the Concentric Canister Launcher (CCL), a universal launch system able to handle the Tomahawk, SM-2 Block IV and Evolved Seasparrow Missile (ESSM). Designed to be capable of simultaneous and co-ordinated launch of multiple missile types, the CCL will be a modular automated design compatible with reduced manning levels.

Vertical launch is also the chosen solution for the Eurosam ED and SD systems. On the aircraft carrier Charles de Gaulle, the first vessel to carry the system, 16-cell Sylver vertical launch systems for Aster 15 missiles are installed on the edge of the deck on the starboard side forward of the bridge and on the port side aft of the bridge. Other systems based on vertical launch include the Matra BAe Seawolf VL, the IAI Barak and Russia’s Rif/SA-N-6 "Grumble" and Klinok/SA-N-9 "Gauntlet".

The Royal Navy sees no long-term future for the area defence surface-to-air missile, arguing that the warning time of an attack by sea-skimming missiles is too short to make long range interception practical. It has abandoned plans to develop a much-improved version of the British Aerospace Sea Dart, or any other new area defence missile. In the short term the Royal Navy settled for a more modest upgrade of the existing system which should keep the Type 42 destroyers combat effective until their planned retirement in 2010 or later. The chosen scheme has modernised the system’s Type 909 Mod 1 target illumination radar, improved the missile guidance section and fitted a new blast fragmentation warhead. The latter is due to be fitted with a new infrared proximity fuze to replace the current radio frequency model.

An Aster missile is prepared for installation in its launch/storage container.

Instead of deploying a next-generation area defence surface-to-air missile, the Royal Navy has focused on a shorter ranged local area defence requirement. The Paams (principal anti-aircraft missile system) for the 6000-tonne Common New Generation Frigate (CNGF) planned by Britain, France and Italy will use Aster 15 missiles to protect the ship on which it is fitted, plus a small number of vessels in the immediate area.

To supplement the Paams, the Royal Navy plans to deploy an inner-layer missile system. Although a formal requirement for a short range surface-to-air missile has not yet been issued, GEC-Marconi has already announced its proposed solution. This is the Sea Sprint, an eight-round naval launcher for a slightly modified version of the Oerlikon Aerospace Adats missile. The only change to the revised missile is the substitution of a radio frequency proximity fuze in place of the current laser pattern. The new fuze is being developed for Oerlikon Aerospace’s planned Mk 2 version of the land-based Adats system, a variant which also introduces the Multipurpose Adats Console (MPAC) in place of the current radar and electro-optical consoles.

Aerospatiale technicians lower an Aster into a vertical launcher at a land-based test site. This manoeuvre is unlikely to be practical at sea – the US Navy accepts that its Aegis cruisers will have to return to port to replenish their vertical launchers.

Matra BAe Dynamics is offering two possible weapons. Its off-the-shelf solution is a version of the six-round Sadral naval mounting for the Mistral, but it also plans to offer the NM21 – a proposed surface-to-air version of the Asraam. This would use the existing Asraam missile but with guidance algorithms optimised for the surface-launch role. Shorts, which already offers a three-round Naval Multiple Launcher (NML) for its Starburst missile, will probably propose its Seastreak derivative of the Starstreak hypersonic missile.

Like the Aegis, the Eurosam ED, SD and Paams are based on a phased array radar. Electronic scanning provides the rapid reaction time needed to follow high-speed targets and switch between multiple targets. Radars of this type are also planned for the Trinational Frigate Programme described later in this article. For its Paams installations, the Royal Navy plans to use the Siemens Sampson active phased array radar. Since active antennas do not require the waveguides and cooling systems associated with passive electronic scanning, their weight is reduced for a given size. This allows the antenna to be mounted as high as possible, giving maximum range to the horizon.