Editing Vertical launching system (section)

==Launch type==
[[File:SM-2 Block IV 080605-N-0000X-006.jpg|thumb|right|upright|A [[RIM-67|RIM-156A missile]] launching from a VLS cell on {{USS|Lake Erie|CG-70|6}} in 2008.]]
[[File:US Navy 090825-N-1522S-020 A Tactical Tomahawk Cruise Missile launches from the forward missile deck aboard the guided-missile destroyer USS Farragut (DDG 99) during a training exercise.jpg|thumb|right|upright|US Navy Mark 41 Tomahawk hot launch.]]

A vertical launch system can be either "hot launch", where the missile ignites in the cell, or "cold launch", where the missile is expelled by gas produced by a [[gas generator]] which is not part of the missile itself, and then the missile ignites. "Cold" means relatively cold compared with rocket engine exhaust. A hot launch system does not require an ejection mechanism but does require some way of disposing of the missile's exhaust and heat as it departs the cell. If the missile ignites in a cell without an ejection mechanism, the cell must withstand the tremendous heat generated without igniting missiles in adjacent cells.

===Hot launch===
An advantage of a hot-launch system is that the missile propels itself out of the launching cell using its own engine, which eliminates the need for a separate system to eject the missile from the launching tube. This potentially makes a hot-launch system relatively light, small, and economical to develop and produce, particularly when designed around smaller missiles. A potential disadvantage is that a malfunctioning missile could destroy the launch tube. American surface-ship VLSs have missile cells arranged in a grid with one lid per cell and are "hot launch" systems. The engine ignites within the cell during the launch and so requires a way of venting rocket exhaust. France, Italy and Britain use a similar hot-launching [[Sylver launcher|Sylver]] system in [[PAAMS]].

===Cold launch===
The advantage of the cold-launch system is in its safety: if a missile engine malfunctions during launch, the cold-launch system can eject the missile, reducing or eliminating the threat. For this reason, Russian VLSs are often designed with a slant so that a malfunctioning missile will land in the water instead of on the ship's deck.  As missile size grows, the benefits of ejection launching increase. Above a certain size, a missile booster cannot be safely ignited within the confines of a ship's hull. Most modern [[intercontinental ballistic missile]]s and [[submarine-launched ballistic missile]]s are cold-launched. [[Russia]] produces both grid systems and a [[revolver]] arrangement with more than one missile per lid for its cold launch system. Russia also uses a cold launch system for some of its vertical launch missile systems, e.g., the [[Tor missile system]].

The United Kingdom's [[CAMM (missile family)|Common Anti-Air Modular Missile (CAMM) family]] of missiles utilises a similar cold-launching system, referred to as "soft-vertical-launch", and actively markets the advantages of the system. Soft-launch provides the missile with a reduce interception rate allowing for shorter ranged engagements, reduces the [[infrared homing]] signature of the ship and the obscurant of visibility by rendering the ship in efflux for several minutes; and most notably, the lack of hot efflux and reduced stress on the ship's structure allows for a much greater choice of launch systems, such as the lighter "Mushroom Farm" launcher whilst also still enabling installation into the heavier Mark 41 in a quad-pack or dual-packed configuration (two or four missiles per cell) for a costly, but more space efficient option.<ref>{{Cite journal |last1=Głębocki |first1=Robert |last2=Jacewicz |first2=Mariusz |date=2018-10-20 |title=Simulation study of a missile cold launch system |url=http://ptmts.org.pl/jtam/index.php/jtam/article/view/4453 |journal=Journal of Theoretical and Applied Mechanics |volume=56 |issue=4 |pages=901–913 |doi=10.15632/jtam-pl.56.4.901 |issn=1429-2955|doi-access=free }}</ref><ref>{{Cite web |date=2019-06-04 |title=From Sea Wolf to Sea Ceptor – the Royal Navy's defensive shield {{!}} Navy Lookout |url=https://www.navylookout.com/from-sea-wolf-to-sea-ceptor-the-royal-navys-defensive-shield/ |access-date=2023-11-10 |website=www.navylookout.com |language=en-GB}}</ref><ref>{{Cite web |title=SEA CEPTOR {{!}} FORCE PROTECTION, Maritime Superiority |url=https://www.mbda-systems.com/product/sea-ceptor/ |access-date=2023-11-10 |website=MBDA |language=en-US}}</ref><ref>{{Cite web |title=CAMM {{!}} FORCE PROTECTION, Ground Based Air Defence |url=https://www.mbda-systems.com/product/camm/ |access-date=2023-11-10 |website=MBDA |language=en-US}}</ref>

===Concentric canister launch===
Some warships of China's [[People's Liberation Army Navy]] use a concentric canister launch (CCL) system that can launch using both hot and cold methods in the cell module, onboard the [[Type 052D destroyer]] and the [[Type 055 destroyer]].<ref>{{cite web|url=https://www.china-arms.com/2020/02/cold-and-hot-launches-052d/|title=Shots of cold and hot launches of 052D destroyer unveiled|website=China-arms|date=19 February 2020}}</ref> The universal launch system is offered for export.<ref>{{cite web|url= https://www.defenseworld.net/news/30531/China_Reveals_Universal_Ship_borne_Vertical_Missile_Launch_System#.YW7_iyWkoWM |title= China Reveals Universal Ship-borne Vertical Missile Launch System |website=defense post|date= 1 October 2021 |archive-url=https://web.archive.org/web/20211001081545/https://www.defenseworld.net/news/30531/China_Reveals_Universal_Ship_borne_Vertical_Missile_Launch_System |archive-date=1 October 2021 |url-status=dead}}</ref>

Older Chinese ships use single launch system: [[Type 052C destroyer]]s use a cold launch system, while [[Type 054A frigate]]s use a hot launch system.<ref>{{cite web |first1=Rick |last1=Joe |url=https://thediplomat.com/2018/06/all-you-need-to-know-about-chinas-new-stealth-destroyer/ |title=All You Need to Know About China's New Stealth Destroyer |website=The Diplomat |date=8 June 2018 |access-date=13 June 2018 |archive-url=https://web.archive.org/web/20180613005400/https://thediplomat.com/2018/06/all-you-need-to-know-about-chinas-new-stealth-destroyer/ |archive-date=13 June 2018 |url-status=live }}</ref>