missiles easy to network into the Navy's emerging Cooperative Engagement Capability. Unlike Block 1, Block 2's active radar homing seeker will support terminal engagement without the launch ship's target illumination radars. The upgraded blast-fragmentation warhead was designed, developed and is being produced by Roketsan. The improved ESSM Block II will be fielded by the US Navy from 2020. Launchers Mk 29 The original launcher is Mark 29 Guided Missile Launching System Mod. 4 & 5 (Mk 29 GMLS Mod 4 & 5), which is developed from earlier models Mk 29 Mod 1/2/3 for Sea Sparrow. Mk 29 launchers provide on-mount stowage and launching capability for firing up to eight missiles in a self-contained environmentally controlled trainable launcher design. Mk 41 The Mark 41 Vertical Launching System is the primary launch system for the Evolved SeaSparrow Missile. The Mk 41 is deployed aboard destroyers and frigates, primarily of the United States and allied nations. The ESSM is quadpacked within a Mk 41 cell allowing a significantly increased missile load over SM-2. Mk 48 In addition to the Mk 29 GMLS and Mk 41 VLS, the other primary launcher is Mk 48 VLS. The 2-cell module of Mk 48 makes the system very versatile and enables it to be installed on board in spaces that otherwise cannot be utilized. The weight of a 2-cell module of Mk 48 is 660 kg (1,450 lb; including empty canisters), 330 kg (725 lb) for exhaust system, and 360 kg (800 lb) for ship installation interfaces. Each canister of the Mk 48 VLS houses a single RIM-7VL (Vertically Launched) Sea Sparrow cell or two RIM-162 ESSM cells, though, with modification, other missiles can also be launched. There are a total of four models in the Mk 48 family, with Mod 0 & 1 housing either 2 RIM-7VL or 4 RIM-162 cells, Mod 2 housing either 16 RIM-7VL or 32 RIM-162 cells. Mod 0/1/2 are usually grouped into either a 16-cell module for RIM-7VL or a 32-cell module for RIM-162. Mod 3 fits into the StanFlex modules on Royal Danish Navy ships and can house either 6 RIM-7VL or 12 RIM-162 cells; the Danes now use the latter. Mk 56 The successor of the Mk 48 VLS is the Mark 56 Guided Missile Vertical Launching System (Mk 56 GMVLS) or simply Mk 56. In comparison to its predecessor, the Mk 56 utilizes a greater percentage of composite