Editing Nimitz-class aircraft carrier (section)

===Armament and protection===
[[File:USS Theodore Roosevelt (CVN-71) Sea Sparrow.jpg|thumb|upright=0.8|alt=Firing of a missile from ''Theodore Roosevelt'' while at sea, seen from the flight deck. There is a Phalanx cannon on the left, with a white, domed upper section and a black cannon on the lower part.|The firing of a [[RIM-7 Sea Sparrow|Sea Sparrow missile]] from ''Theodore Roosevelt''. A [[Phalanx CIWS]] is in the left of the image.]]
[[File:US Navy 050615-N-8148A-063 The Nimitz-class aircraft carrier USS Ronald Reagan (CVN 76) activates her countermeasures wash down system as part of a series of test and evaluations to certify the vessel in the event of a chemical.jpg|thumb|upright=0.8|The counter-measure wash-down system of ''Ronald Reagan'' being tested. This is part of the ship's [[CBRN|defense]] against chemical, biological or radiological threats, and also against fires]]

In addition to the aircraft carried on board, the ships carry defensive equipment for use against missiles and hostile aircraft. These consist of either two or three [[RIM-7 Sea Sparrow]] or [[RIM-162 ESSM|RIM-162 Evolved SeaSparrow Missile]] Mk 29 missile launchers designed for defense against aircraft and [[anti-ship missile]]s, as well as either three or four 20&nbsp;mm [[Phalanx CIWS]].<ref>Wertheim 2005, pp. 919–920</ref>

USS ''Ronald Reagan'' has none of these, having been built with the Mk 49 Guided Missile Launching Systems for [[RIM-116 Rolling Airframe Missile]]s, two of which have also been installed on {{USS|Nimitz|CVN-68|6}} and {{USS|George Washington|CVN-73|6}}. These will be installed on the other ships as they return for [[Refueling Complex Overhaul]] (RCOH).<ref name="SE" /><ref name="Navy.mil CVN"/> Since USS ''Theodore Roosevelt'', the carriers have been constructed with {{convert|2.5|in|mm|abbr=on}} [[Kevlar]] armor over vital spaces, and earlier ships have been retrofitted with it: ''Nimitz'' in 1983–1984, ''Dwight D. Eisenhower'' from 1985 to 1987 and ''Carl Vinson'' in 1989.<ref name="Fontenoy"/><ref>Wertheim 2007, p. 884</ref>

The ships' other countermeasures are four Sippican [[SRBOC]] (super rapid bloom off-board [[chaff]]) six-barrel Mk 36 decoy launchers, which deploy infrared [[Flare (countermeasure)|flares]] and [[Chaff (countermeasure)|chaff]] to disrupt the sensors of incoming missiles; an SSTDS torpedo defense system; and an [[AN/SLQ-25 Nixie]] torpedo countermeasures system. The carriers also use [[AN/SLQ-32 Electronic Warfare Suite|AN/SLQ-32(V)]] [[Radar jamming and deception|jamming]] systems to detect and disrupt hostile [[radar]] signals in addition to the [[electronic warfare]] capabilities of some of the aircraft on board.<ref>Wertheim 2007, p. 885</ref><ref>Polmar 2004, p. 108</ref>

The presence of [[Tactical nuclear weapon|nuclear weapon]]s on board U.S. aircraft carriers since the end of the Cold War has neither been confirmed nor denied by the U.S. government. As a result, the presence of a U.S. aircraft carrier in a foreign port has occasionally provoked protest from local people, for example, when ''Nimitz'' visited [[Chennai]], India, in 2007. At that time, the Strike Group commander [[Rear admiral (United States)|Rear Admiral]] John Terence Blake stated, "The U.S. policy [...] is that we do not routinely deploy nuclear weapons on board ''Nimitz''."<ref>{{cite news |url=http://www.indianexpress.com/news/nimitz-docks-off-chennai-to-build-new-relat/203639/ |title=Nimitz docks off Chennai to 'build new relations with India' |date= 3 July 2007 |newspaper=[[The Indian Express]] |access-date=11 January 2010}}</ref><ref>{{cite magazine |url=http://www.hinduonnet.com/fline/fl2414/stories/20070727000806200.htm |title=NAM and Nimitz |date=14–27 July 2007 |magazine=[[Frontline (magazine)|Frontline]] |access-date=11 January 2010 |url-status=usurped |archive-url=https://web.archive.org/web/20101209044846/http://www.hinduonnet.com/fline/fl2414/stories/20070727000806200.htm |archive-date=9 December 2010 |df=dmy-all}}</ref>

In May 2013, ''George H.W. Bush'' conducted the first carrier-borne end-to-end at-sea test of the Surface Ship Torpedo Defense System (SSTDS). The SSTDS combined the passive detection of the Torpedo Warning System (TWS) that finds, classifies, and tracks torpedoes with the hard-kill capability of a Countermeasure Anti-Torpedo (CAT), an encapsulated miniature torpedo designed to locate, home in on, and destroy hostile torpedoes.<ref>[http://www.navy.mil/submit/display.asp?story_id=74665 First Carrier Countermeasure Anti-Torpedo Launched] {{Webarchive|url=https://web.archive.org/web/20150727112816/http://www.navy.mil/submit/display.asp?story_id=74665 |date=27 July 2015}} – Navy.mil, 6 June 2013</ref> This was to increase protection against wake-homing torpedoes like the [[Type 53 torpedo|Type 53]] that do not respond to acoustic decoys. The pieces of the SSTDS were engineered to locate and destroy incoming torpedoes in a matter of seconds; each system included one TWS and 8 CATs. Initial operational capability (IOC) was planned for 2019, and all aircraft carriers were to be outfitted by 2035.<ref>[http://news.usni.org/2013/06/20/navy-develops-torpedo-killing-torpedo Navy Develops Torpedo Killing Torpedo] {{Webarchive|url=https://web.archive.org/web/20151208120511/http://news.usni.org/2013/06/20/navy-develops-torpedo-killing-torpedo |date=8 December 2015}} – News.USNI.org, 20 June 2013</ref><ref>{{usurped|1=[https://web.archive.org/web/20151208094936/http://defensetech.org/2013/10/28/navy-deploying-new-anti-torpedo-technology/ Navy Deploying New Anti-Torpedo Technology]}} – Defensetech.org, 28 October 2013</ref><ref>[http://www.navyrecognition.com/index.php/news/defence-news/year-2015-news/march-2015-navy-naval-forces-defense-industry-technology-maritime-security-global-news/2495-us-navy-continues-work-on-torpedo-warning-systemcountermeasure-anti-torpedo-system.html US Navy Continues Work on Torpedo Warning System/Countermeasure Anti-Torpedo System] {{Webarchive|url=https://web.archive.org/web/20151208174617/http://www.navyrecognition.com/index.php/news/defence-news/year-2015-news/march-2015-navy-naval-forces-defense-industry-technology-maritime-security-global-news/2495-us-navy-continues-work-on-torpedo-warning-systemcountermeasure-anti-torpedo-system.html |date=8 December 2015}} – Navyrecognition.com, 12 March 2015</ref> The Navy suspended work on the project in September 2018 due to poor reliability of the components; hardware, already installed on five carriers, is to be removed by 2023.<ref>[https://www.dote.osd.mil/Portals/97/pub/reports/FY2018/navy/2018sstd_tws_cat.pdf?ver=2019-08-21-155651-040 Surface Ship Torpedo Defense (SSTD) System]. ''[[Director, Operational Test and Evaluation|Office of the Director of Test and Evaluation]]''. FY18 NAVY PROGRAMS.</ref><ref>[https://www.thedrive.com/the-war-zone/26347/the-navy-is-ripping-out-underperforming-anti-torpedo-torpedoes-from-its-supercarriers The Navy Is Ripping Out Underperforming Anti-Torpedo Torpedoes From Its Supercarriers]. ''The Drive.com/The War Zone''. 5 February 2019.</ref>