Editing Proton (rocket family) (section)

==History==
Proton<ref>{{cite web |url=http://www.ilslaunch.com/launch-services/ils-proton-breeze-m-launch-vehicle/proton-heritage |title=Proton Heritage |publisher=International Launch Services}}</ref> started its life as a "super [[heavy ICBM]]". It was designed to launch a 100-[[TNT equivalent|megaton]] (or larger) [[thermonuclear weapon]] over a distance of 13,000&nbsp;km. It was hugely oversized for an ICBM and was never deployed in such a capacity. It was eventually used as a space [[launch vehicle]]. It was the brainchild of [[Vladimir Chelomei]]'s design bureau as a foil to [[Sergei Korolev]]'s [[N1 (rocket)|N1]] rocket, whose purpose was to send a two-man [[Zond program|Zond]] spacecraft around the Moon; Korolev openly opposed Proton and Chelomei's other designs for their use of toxic propellants. 

The unusual appearance of the first stage results from the need to transport components by rail. The central oxidizer tank is the maximum width for the [[loading gauge]] of the track. The six tanks surrounding it carry fuel and serve as the attachment points for the engines. Despite resembling [[booster (rocketry)|strap-on booster]]s, they are not designed to separate from the central oxidizer tank. The first and second stages are connected by a lattice structure. The second stage engine ignites shortly before separation of the first stage and the lattice allows the exhaust to escape.<ref>[http://www.russianspaceweb.com/proton_stage1.html The first stage of the Proton rocket] at Russian Space Web</ref> This is called "hot staging" and it eliminates the need for [[ullage motor]]s on the second stage.

A rushed development program led to dozens of failures between 1965 and 1972. Proton did not complete its State Trials until 1977, at which point it was judged to have a higher than 90% reliability.

Proton's design was kept secret until 1986, with the public being only shown the upper stages in film clips and photographs, and the first time the complete vehicle was shown to the outside world happened during the televised launch of [[Mir]].

Mass-production of [[guidance, navigation and control]] system for Proton has begun in 1964 on "Communard" Industrial Association ([[Kharkov, Ukraine]]).<ref name="History">{{cite web |title=History of SSIA "Communard" |url=http://www.tvset.com.ua/en/about/ |access-date=5 May 2019 |archive-date=27 January 2021 |archive-url=https://web.archive.org/web/20210127171628/https://www.tvset.com.ua/en/about/ |url-status=dead }}</ref>

Proton launched the uncrewed Soviet circumlunar flights and was intended to have launched the first crewed Soviet [[circumlunar]] spaceflights, before the United States flew the [[Apollo 8]] mission. Proton launched the [[Salyut]] space stations, the [[Mir]] core segment and expansion modules, and both the [[Zarya (ISS module)|Zarya]] and [[Zvezda (ISS module)|Zvezda]] modules of the [[International Space Station|ISS]].

Proton also launches commercial [[satellite]]s, most of them being managed by [[International Launch Services]]. The first ILS Proton launch was on 9 April 1996 with the launch of the [[SES (company)|SES]] [[Astra 1F]] [[communications satellite]].<ref name="ilslaunch">{{cite web|url=http://www.ilslaunch.com/mission-control/proton-launch-archives|title=Proton Launch Archives &#124; International Launch Services|publisher=ilslaunch.com|access-date=13 September 2014}}</ref>

Between 1994 and mid-2010, Proton revenues were $4.3&nbsp;billion, and were projected to grow to $6&nbsp;billion by 2011.<ref name="nesterov">{{cite web |url=http://www.khrunichev.ru/main.php?id=1&nid=1735 |title=Statement by Vladimir Ye. Nesterov, Khrunichev Director-General, at Press Conference on 15 July 2010
|archive-url=https://web.archive.org/web/20190924112805/http://www.khrunichev.ru/main.php?id=1&nid=1735 |archive-date=24 September 2019 |url-status=dead}}</ref>

In January 2017, the Proton was temporarily grounded due to the manufacturer, [[Voronezh Mechanical Plant]], having substituted a heat-resistant alloy in the engines with a cheaper metal.<ref>{{Cite web|url=http://www.planetary.org/blogs/guest-blogs/2017/20170125-proton-rocket-grounded.html|title=Russia's Proton rocket grounded by poor quality control|website=www.planetary.org|language=en|access-date=2017-01-26}}</ref><ref>{{Cite web|url=http://spaceflight101.com/proton-rocket-faces-extended-grounding/|title=Russia's Proton Rocket faces extended Grounding due to systemic Engine Problems|website=spaceflight101.com|date=25 January 2017 |language=en|access-date=2017-02-24}}</ref>

In June 2018, the [[state corporation]] [[Roscosmos]] announced that the Proton rocket would cease production as the new [[Angara (rocket family)|Angara]] launch vehicle comes on line and becomes operational. No new launch service contracts for Proton are likely to be signed.<ref name=asr20100625>
{{cite news |last=Berger|first=Eric |url=https://arstechnica.com/science/2018/06/russias-proton-rocket-which-predates-apollo-will-finally-stop-flying/ |title=Russia's Proton rocket, which predates Apollo, will finally stop flying Technical problems, rise of SpaceX are contributing factors. |work=arsTechica |date=25 June 2018 |access-date=26 June 2018 |quote="...failures have followed in recent years. These problems, combined with the rapid rise of low-cost alternatives such as SpaceX's Falcon 9 rocket, have caused the number of Proton launches in a given year to dwindle from eight or so to just one or two."}}</ref>

Proton flew its last scheduled commercial mission on 9 October 2019, delivering [[Eutelsat 5 West B]] and [[Mission Extension Vehicle]]-1 to geostationary orbit.<ref>{{Cite web|url=http://russianspaceweb.com/eutelsat5wb-mev1.html|title=Proton flies its last scheduled commercial mission|website=russianspaceweb.com}}</ref> A number of Roscosmos and other Russian government missions remain on Proton launch manifest.