Editing Challenger Deep (section)

===Manned descents===
[[File: Bathyscaphe Trieste.jpg|thumb|Bathyscaphe ''Trieste''. The spherical crew cabin is attached to the underside of a tank filled with gasoline (which is incompressible), which serves as a float giving the craft buoyancy.]]
[[File: Bathyscaphe Trieste Piccard-Walsh.jpg|thumb|upright|Lt. Don Walsh, USN (bottom) and Jacques Piccard (center) in the ''Trieste'']]

====1960 – ''Trieste''====
{{Main|Bathyscaphe Trieste}}
On 23 January 1960, the Swiss-designed [[Bathyscaphe Trieste|''Trieste'']], originally built in Italy and acquired by the [[United States Navy|U.S. Navy]], supported by the USS ''Wandank'' (ATF 204) and escorted by the USS ''Lewis'' (DE 535), descended to the ocean floor in the trench piloted by [[Jacques Piccard]] (who co-designed the submersible along with his father, [[Auguste Piccard]]) and USN Lieutenant [[Don Walsh]]. Their crew compartment was inside a spherical pressure vessel – measuring 2.16 metres in diameter suspended beneath a buoyancy tank 18.4 metres in length<ref name=":0">{{Cite web|url=https://www.smh.com.au/environment/descent-to-challenger-deep-20110413-1ddnq.html|title=Descent to Challenger Deep|last=Kwek|first=Glenda|date=13 April 2011|website=The Sydney Morning Herald|language=en|access-date=31 July 2019|archive-date=31 July 2019|archive-url=https://web.archive.org/web/20190731175727/https://www.smh.com.au/environment/descent-to-challenger-deep-20110413-1ddnq.html|url-status=live}}</ref> – which was a heavy-duty replacement (of the Italian original) built by [[Krupp]] Steel Works of [[Essen]], [[Germany]]. The [[steel]] walls were {{cvt|12.7|cm|in}} thick and designed to withstand pressure of up to {{convert|1250|kg/cm2|psi atm MPa|abbr=out|comma=off}}.<ref name=":0" />
Their descent took almost five hours and the two men spent barely twenty minutes on the ocean floor before undertaking the three-hour-and-fifteen-minute ascent. Their early departure from the [[Seabed|ocean floor]] was due to their concern over a crack in the outer window caused by the temperature differences during their descent.<ref name="National Geographics">{{cite web |url=http://deepseachallenge.com/the-expedition/1960-dive/ |title=1960 Dive - DEEPSEA CHALLENGE Expedition |access-date=10 April 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120414093239/http://deepseachallenge.com/the-expedition/1960-dive/ |archive-date=14 April 2012}}</ref>

''Trieste'' dived at/near {{Coord|11|18.5|N|142|15.5|E}}, bottoming at {{convert|10911|m|ft}} ±{{convert|7|m|ft|0|abbr=on}} into the Challenger Deep's ''western'' basin, as measured by an onboard [[manometer]].<ref>Piccard, J. "Seven Miles Deep," ''G.P. Putnam's Sons'', 1961, p. 242</ref> Another source states the measured depth at the bottom was measured with a [[manometer]] at {{convert|10913|m|0|abbr=on}} ±{{convert|5|m|ft|0|abbr=on}}.<ref name="Bathymetric mapping of the world's deepest seafloor, Challenger Deep" /><ref name="usn1960">{{cite web
|author=Press Release, Office of Naval Research
|date=1 February 1960
|url=http://www.onr.navy.mil/focus/ocean/vessels/submersibles11.htm
|title=Research Vessels: Submersibles – ''Trieste''
|publisher=United States Navy
|access-date=16 May 2010
|url-status=dead
|archive-url=https://web.archive.org/web/20020418105908/http://www.onr.navy.mil/focus/ocean/vessels/submersibles11.htm
|archive-date=18 April 2002
}}</ref>
Navigation of the support ships was by celestial and [[LORAN-C]] with an accuracy of {{convert|460|m|ft}} or less.<ref name="jproc.ca"/> Fisher noted that the ''Trieste'''s reported depth "agrees well with the sonic sounding."<ref>Fisher, Trenches, ''The Earth Beneath the Sea'', p. 416</ref>

====2012 – ''Deepsea Challenger''====
{{main|Deepsea Challenger}}
[[File:Deepsea Challenger Panorama.jpg|thumb|DSV ''Deepsea Challenger'']]
On 26 March 2012 (local time), Canadian film director [[James Cameron]] made a solo descent in the [[deep submergence vehicle|DSV]] ''Deepsea Challenger'' to the bottom of the Challenger Deep.<ref name="NGS-20120325">{{cite web|last=Than|first=Ker|title=James Cameron Completes Record-Breaking Mariana Trench Dive|url=http://news.nationalgeographic.com/news/2012/03/120325-james-cameron-mariana-trench-challenger-deepest-returns-science-sub/|date=25 March 2012|publisher=[[National Geographic Society]]|access-date=25 March 2012|archive-date=16 May 2019|archive-url=https://web.archive.org/web/20190516231005/https://news.nationalgeographic.com/news/2012/03/120325-james-cameron-mariana-trench-challenger-deepest-returns-science-sub/|url-status=dead}}</ref><ref name="NYT-20120325">{{cite news |last=Broad|first=William J. |title=Filmmaker in Submarine Voyages to Bottom of Sea|url=https://www.nytimes.com/2012/03/26/science/james-camerons-submarine-trip-to-challenger-deep.html |archive-url=https://ghostarchive.org/archive/20220101/https://www.nytimes.com/2012/03/26/science/james-camerons-submarine-trip-to-challenger-deep.html |archive-date=2022-01-01 |url-access=limited|date=25 March 2012 |work=[[The New York Times]] |access-date=25 March 2012}}{{cbignore}}</ref><ref name="MSNBC-20120325">{{cite web |author=AP Staff |title=James Cameron has reached deepest spot on Earth |url=https://www.nbcnews.com/id/wbna46850002 |date=25 March 2012 |work=[[NBC News]] |access-date=25 March 2012 |archive-date=30 September 2020 |archive-url=https://web.archive.org/web/20200930203233/http://www.nbcnews.com/id/46850002 |url-status=live }}</ref><ref>{{cite news|last=Prince |first=Rosa |url=https://www.telegraph.co.uk/news/worldnews/australiaandthepacific/guam/9166425/James-Cameron-becomes-first-solo-diver-to-visit-Earths-deepest-point.html |archive-url=https://ghostarchive.org/archive/20220111/https://www.telegraph.co.uk/news/worldnews/australiaandthepacific/guam/9166425/James-Cameron-becomes-first-solo-diver-to-visit-Earths-deepest-point.html |archive-date=11 January 2022 |url-access=subscription |url-status=live |title=James Cameron becomes first solo diver to visit Earth's deepest point |newspaper=The Telegraph |date=25 March 2012 |access-date=26 March 2012}}{{cbignore}}</ref>
At approximately 05:15 [[ChST]] on 26 March (19:15 UTC on 25 March), the descent began.<ref name="James Cameron Begins Descent to Ocean's Deepest Point">{{cite web |author=National Geographic |title=James Cameron Begins Descent to Ocean's Deepest Point |url=http://news.nationalgeographic.com/news/2012/03/120325-james-cameron-mariana-trench-dive-deepest-science-sub-descent/ |date=25 March 2012 |publisher=National Geographic Society |access-date=25 March 2012 |archive-date=27 March 2012 |archive-url=https://web.archive.org/web/20120327014617/http://news.nationalgeographic.com/news/2012/03/120325-james-cameron-mariana-trench-dive-deepest-science-sub-descent/ |url-status=dead }}</ref>
At 07:52 ChST (21:52 UTC), ''Deepsea Challenger'' arrived at the bottom. The descent lasted 2 hours and 36 minutes and the recorded depth was {{convert|10908|m|ft}} when ''Deepsea Challenger'' touched down.<ref name="James Cameron Now at Ocean's Deepest Point">{{cite web |author=National Geographic |title=James Cameron Now at Ocean's Deepest Point |url=http://news.nationalgeographic.com/news/2012/03/120325-james-cameron-mariana-trench-challenger-deep-deepest-science-sub/ |date=25 March 2012 |publisher=National Geographic Society |access-date=25 March 2012 |archive-date=27 March 2012 |archive-url=https://web.archive.org/web/20120327053619/http://news.nationalgeographic.com/news/2012/03/120325-james-cameron-mariana-trench-challenger-deep-deepest-science-sub/ |url-status=dead }}</ref>
Cameron had planned to spend about six hours near the ocean floor exploring but decided to start the ascent to the surface after only 2 hours and 34 minutes.<ref name="Cameron's Historic Dive Cut Short by Leak; Few Signs of Life Seen">{{cite web |author=National Geographic |title=Cameron's Historic Dive Cut Short by Leak; Few Signs of Life Seen |url=http://news.nationalgeographic.com/news/2012/03/120326-james-cameron-mariana-trench-fluid-leak-fish-science-sub/ |date=26 March 2012 |publisher=National Geographic Society |access-date=26 March 2012 |archive-date=28 March 2012 |archive-url=https://web.archive.org/web/20120328060000/http://news.nationalgeographic.com/news/2012/03/120326-james-cameron-mariana-trench-fluid-leak-fish-science-sub/ |url-status=dead }}</ref> The time on the bottom was shortened because a hydraulic fluid leak in the lines controlling the manipulator arm obscured the visibility out of the only viewing port. It also caused the loss of the submersible's starboard thrusters.<ref name="Problems at the bottom">{{cite web |author=National Geographic |title=Cameron's Historic Dive Cut Short by Leak; Few Signs of Life Seen |url=http://news.nationalgeographic.com/news/2012/03/120326-james-cameron-mariana-trench-fluid-leak-fish-science-sub/ |date=28 March 2012 |publisher=National Geographic Society |access-date=28 March 2012 |archive-date=28 March 2012 |archive-url=https://web.archive.org/web/20120328060000/http://news.nationalgeographic.com/news/2012/03/120326-james-cameron-mariana-trench-fluid-leak-fish-science-sub/ |url-status=dead }}</ref> At around 12:00 ChST (02:00 UTC on 26 March), the Deepsea Challenger website says the sub resurfaced after a 90-minute ascent,<ref name="We Just Did the Impossible">{{cite web |author=deepseachallenge.com |title=We Just Did the Impossible |url=http://deepseachallenge.com/expedition-journal/we-just-did-the-impossible/ |date=25 March 2012 |publisher=deepseachallenge.com |access-date=26 March 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120329093127/http://deepseachallenge.com/expedition-journal/we-just-did-the-impossible/ |archive-date=29 March 2012}}</ref> although [[Paul Allen]]'s tweets indicate the ascent took only about 67 minutes.<ref>{{cite tweet|number=184097111770529793|user=PaulGAllen|title=#deepseachallenge has surfaced, now for recovery...<!-- full text of tweet that Twitter returned to the bot (excluding links) added by TweetCiteBot. This may be better truncated or may need expanding (TW limits responses to 140 characters) or case changes. --> |accessdate=22 July 2022|date=26 March 2012}}</ref> During a post-dive press conference Cameron said: "I landed on a very soft, almost gelatinous flat plain. Once I got my bearings, I drove across it for quite a distance ... and finally worked my way up the slope." The whole time, Cameron said, he didn't see any fish, or any living creatures more than an inch (2.54&nbsp;cm) long: "The only free swimmers I saw were small [[amphipods]]" – shrimplike bottom-feeders.<ref name="James Cameron on Earth's Deepest Spot: Desolate, Lunar-Like">{{cite web |author=National Geographic |title=James Cameron on Earth's Deepest Spot: Desolate, Lunar-Like |url=http://news.nationalgeographic.com/news/2012/03/120326-james-cameron-mariana-trench-challenger-deepest-lunar-sub-science/ |date=27 March 2012 |publisher=National Geographic Society |access-date=27 March 2012 |archive-date=28 March 2012 |archive-url=https://web.archive.org/web/20120328064958/http://news.nationalgeographic.com/news/2012/03/120326-james-cameron-mariana-trench-challenger-deepest-lunar-sub-science/ |url-status=dead }}</ref>

====2019 – ''Five Deeps Expedition / DSV Limiting Factor''====
{{main|DSV Limiting Factor}}
[[File:Limiting Factor to be prepared for a dive into the Atlantic Ocean.jpg|thumb|DSSV ''Pressure Drop'' and DSV ''Limiting Factor'' at its stern]]
[[File:Skaf and Closp shortly before a launch.jpg|thumb|The landers ''Skaff'' and ''Closp'' are prepared for a deployment during the Five Deeps Expedition.|alt=]]

The Five Deeps Expedition's objective was to thoroughly map and visit the deepest points of all five of the world's oceans by the end of September 2019.<ref>{{cite web|url=https://fivedeeps.com/|title=Home|website=fivedeeps.com|access-date=9 January 2019|archive-date=11 January 2019|archive-url=https://web.archive.org/web/20190111180529/https://fivedeeps.com/|url-status=live}}</ref> On 28 April 2019, explorer [[Victor Vescovo]] descended to the "Eastern Pool" of the Challenger Deep in the Deep-Submergence Vehicle ''Limiting Factor'' (a Triton 36000/2 model submersible).<ref>{{cite web |url=https://fivedeeps.com/home/technology/sub/ |title=Full Ocean Depth Submersible LIMITING FACTOR |work=fivedeeps.com |access-date=18 May 2019 |archive-date=14 May 2019 |archive-url=https://web.archive.org/web/20190514014338/https://fivedeeps.com/home/technology/sub/ |url-status=live }}</ref><ref name="BBC News">{{cite news |url=https://www.bbc.co.uk/news/science-environment-48230157 |title=Mariana Trench: Deepest-ever sub dive finds plastic bag |work=BBC News |date=13 May 2019 |access-date=13 May 2019 |archive-date=13 May 2019 |archive-url=https://web.archive.org/web/20190513141623/https://www.bbc.co.uk/news/science-environment-48230157 |url-status=live }}</ref> Between 28 April and 4 May 2019, the ''Limiting Factor'' completed four dives to the bottom of Challenger Deep. The fourth dive descended to the slightly less deep "Central Pool" of the Challenger Deep (crew: Patrick Lahey, Pilot; John Ramsay, Sub Designer). The Five Deeps Expedition estimated maximum depths of {{Convert|10927|m|ft|abbr=on}} ±{{Convert|8|m|ft|abbr=on}} and {{Convert|10928|m|ft|abbr=on}} ±{{Convert|10.5|m|ft|abbr=on}} at ({{Coord|11.3693|N|142.5889|E|scale:100000}}) by direct [[CTD (instrument)|CTD]] pressure measurements and a survey of the operating area by the support ship, the Deep Submersible Support Vessel ''[[USNS Indomitable (T-AGOS-7)|DSSV ''Pressure Drop'']]'', with a Kongsberg SIMRAD EM124 multibeam echosounder system. The CTD measured pressure at {{Convert|10928|m|ft|abbr=on}} of seawater depth was {{convert|1126.79|bar|MPa psi|abbr=on}}.<ref>{{cite web|url=https://fivedeeps.com/home/technology/sub/certification/|title=Full Ocean Depth Submersible DNV-GL CERTIFICATION|work=fivedeeps.com|access-date=4 May 2019|archive-date=3 November 2019|archive-url=https://web.archive.org/web/20191103145726/https://fivedeeps.com/home/technology/sub/certification/|url-status=live}}</ref><ref name="ioc-unesco.org">{{cite web|url=http://ioc-unesco.org/index.php?option=com_oe&task=viewDocumentRecord&docID=3939|title=UNESCO Technical Papers in Marine Science 44, Algorithms for computation of fundamental properties of seawater|work=ioc-unesco.org|date=1983|access-date=9 November 2019|archive-date=27 July 2020|archive-url=https://web.archive.org/web/20200727192427/http://ioc-unesco.org/index.php?option=com_oe&task=viewDocumentRecord&docID=3939|url-status=live}}</ref> Due to a technical problem the (uncrewed) [[benthic lander|ultra-deep-sea lander ''Skaff'']] used by the Five Deeps Expedition stayed on the bottom for two and half days before it was salvaged by the ''Limiting Factor'' (crew: Patrick Lahey, Pilot; Jonathan Struwe, [[DNV GL]] Specialist) from an estimated depth of {{convert|10927|m|ft|abbr=on}}.<ref>{{cite web|url=https://www.dnvgl.com/expert-story/maritime-impact/Dive-to-the-ultimate-abyss.html|title=Dive to the ultimate abyss|work=dnvgl.com|access-date=19 December 2019|archive-date=22 December 2019|archive-url=https://web.archive.org/web/20191222083907/https://www.dnvgl.com/expert-story/maritime-impact/Dive-to-the-ultimate-abyss.html|url-status=live}}</ref><ref name="ioc-unesco.org"/> The gathered data was published with the caveat that it was subject to further analysis and could possibly be revised in the future. The data will be donated to the GEBCO Seabed 2030 initiative.<ref>{{cite web |url=https://fivedeeps.com/wp-content/uploads/2019/05/FDE-Challenger-Release-FINAL-5132019.pdf |title=Deepest Submarine Dive in History, Five Deeps Expedition Conquers Challenger Deep |work=fivedeeps.com |access-date=13 May 2019 |archive-date=3 February 2020 |archive-url=https://web.archive.org/web/20200203210835/https://fivedeeps.com/wp-content/uploads/2019/05/FDE-Challenger-Release-FINAL-5132019.pdf |url-status=live }}</ref><ref name="BBC News"/><ref>{{cite web| url = https://seabed2030.gebco.net/| title = The Nippon Foundation-GEBCO Seabed 2030 Project| access-date = 19 June 2019| archive-date = 16 June 2019| archive-url = https://web.archive.org/web/20190616070107/https://seabed2030.gebco.net/| url-status = dead}}</ref><ref>{{cite web|url=https://seabed2030.gebco.net/resources_for_journalists/press_release_2019-03-11.html|title=Major partnership announced between The Nippon Foundation-GEBCO Seabed 2030 Project and The Five Deeps Expedition|date=11 March 2019|website=gebco.net|access-date=19 June 2019|archive-date=19 June 2019|archive-url=https://web.archive.org/web/20190619174227/https://seabed2030.gebco.net/resources_for_journalists/press_release_2019-03-11.html|url-status=dead}}</ref><ref>{{cite web |url=https://fivedeeps.com/home/technology/landers/ |title=Science Landers Flere, Skaff & Closp |work=fivedeeps.com |access-date=22 October 2019 |archive-date=19 July 2019 |archive-url=https://web.archive.org/web/20190719171454/https://fivedeeps.com/home/technology/landers/ |url-status=live }}</ref> Later in 2019, following a review of bathymetric data, and multiple sensor recordings taken by the DSV ''Limiting Factor'' and the ultra-deep-sea landers ''Closp'', ''Flere'' and ''Skaff'', the Five Deeps Expedition revised the maximum depth to {{Convert|10925|m|ft|abbr=on}} ±{{Convert|4|m|ft|abbr=on}}.<ref>{{cite web |url=https://fivedeeps.com/home/expedition/ |title=The Five Deeps Expedition Overview |work=fivedeeps.com |access-date=5 November 2019 |archive-date=10 June 2019 |archive-url=https://web.archive.org/web/20190610030231/https://fivedeeps.com/home/expedition/ |url-status=live }}</ref>

====2020 – ''Ring of Fire Expedition / DSV Limiting Factor''====
{{main|DSV Limiting Factor}}
[[File:Limiting Factor floating on the water surface.jpg|thumb|DSV ''Limiting Factor'' floating on the water surface]]

Caladan Oceanic's "Ring of Fire" expedition in the Pacific included six manned descents and twenty-five lander deployments into all three basins of the Challenger Deep all piloted by [[Victor Vescovo]] and further topographical and marine life survey of the entire Challenger Deep.<ref>{{cite web |url=https://caladanoceanic.com/expeditions/ringoffire/ |title=The Ring of Fire Expedition Overview |work=caladanoceanic.com |access-date=9 June 2020 |archive-date=8 June 2020 |archive-url=https://web.archive.org/web/20200608152244/https://caladanoceanic.com/expeditions/ringoffire/ |url-status=live }}</ref> The expedition craft used are the Deep Submersible Support Vessel DSSV ''Pressure Drop'', Deep-Submergence Vehicle DSV ''Limiting Factor'' and the ultra-deep-sea landers ''Closp'', ''Flere'' and ''Skaff''.
During the first manned dive on 7 June 2020 Victor Vescovo and former US astronaut (and former NOAA Administrator) [[Kathryn D. Sullivan]] descended to the "Eastern Pool" of the Challenger Deep in the Deep-Submergence Vehicle ''Limiting Factor''.<ref>{{cite web |url=http://www.collectspace.com/news/news-060820a-astronaut-sullivan-challenger-deep.html |title=Former astronaut becomes first person to visit both space and the deepest place in the ocean |work=collectspace.com |access-date=9 June 2020 |archive-date=11 July 2020 |archive-url=https://web.archive.org/web/20200711022902/http://www.collectspace.com/news/news-060820a-astronaut-sullivan-challenger-deep.html |url-status=live }}</ref><ref>{{cite web |url=https://edition.cnn.com/travel/article/astronaut-kathy-sullivan-challenger-deep-dive-scn/index.html |title=Astronaut Kathy Sullivan is first woman to dive to Challenger Deep |work=cnn.com |date=10 June 2020 |access-date=10 June 2020 |archive-date=10 June 2020 |archive-url=https://web.archive.org/web/20200610145606/https://edition.cnn.com/travel/article/astronaut-kathy-sullivan-challenger-deep-dive-scn/index.html |url-status=live }}</ref>

On 12 June 2020, Victor Vescovo and mountaineer and explorer [[Vanessa O'Brien]] descended to the "Eastern Pool" of the Challenger Deep spending three hours mapping the bottom. O'Brien said her dive scanned about a mile of desolate bottom terrain, finding that the surface is not flat, as once was thought, but sloping by about {{convert|18|ft|m|1|abbr=on|lk=on}} per mile, subject to verification.<ref>{{cite web |url=https://metro.co.uk/2020/06/16/female-explorer-becomes-first-reach-highest-lowest-points-planet-reveals-what-was-like-journeying-4-hours-ocean-floor-12857647/ |title=Explorer becomes the first woman to reach the highest and lowest points on the planet |work=metro.co.uk |date=16 June 2020 |access-date=23 June 2020 |archive-date=16 June 2020 |archive-url=https://web.archive.org/web/20200616134000/https://metro.co.uk/2020/06/16/female-explorer-becomes-first-reach-highest-lowest-points-planet-reveals-what-was-like-journeying-4-hours-ocean-floor-12857647/ |url-status=live }}</ref><ref>{{cite web |url=https://jedennews.com/second-woman-to-make-challenger-deep-ocean-dive/ |title=Second Woman to Make Challenger Deep Ocean Dive |work=jedennews.com |access-date=13 June 2020 |archive-date=13 June 2020 |archive-url=https://web.archive.org/web/20200613100758/https://jedennews.com/second-woman-to-make-challenger-deep-ocean-dive/ |url-status=dead }}</ref><ref>{{cite web |url=https://www.forbes.com/sites/jimclash/2020/06/18/voyage-to-the-bottom-of-the-earth/ |title=Voyage to the Bottom of the Earth |work=forbes.com |access-date=21 June 2020 |archive-date=7 July 2020 |archive-url=https://web.archive.org/web/20200707063259/https://www.forbes.com/sites/jimclash/2020/06/18/voyage-to-the-bottom-of-the-earth/ |url-status=live }}</ref><ref>{{Cite web|title=To the Bottom of the Sea: Interview with Vanessa O'Brien|url=https://explorersweb.com/2020/06/23/to-the-bottom-of-the-sea-interview-with-vanessa-obrien/|access-date=2020-06-25|website=Explorersweb|date=23 June 2020 |archive-date=25 June 2020|archive-url=https://web.archive.org/web/20200625162246/https://explorersweb.com/2020/06/23/to-the-bottom-of-the-sea-interview-with-vanessa-obrien/|url-status=live}}</ref>
On 14 June 2020, Victor Vescovo and John Rost descended to the "Eastern Pool" of the Challenger Deep in the Deep-Submergence Vehicle ''Limiting Factor'' spending four hours at depth and transiting the bottom for nearly 2 miles.<ref>{{cite tweet|number=1272342697551028230|user=VictorVescovo|title=Yesterday we just completed the deepest, longest dive ever. Mission specialist John Rost and I explored the Eastern…<!-- full text of tweet that Twitter returned to the bot (excluding links) added by TweetCiteBot. This may be better truncated or may need expanding (TW limits responses to 140 characters) or case changes. --> |accessdate=21 June 2020|date=15 June 2020}}</ref>
On 20 June 2020, Victor Vescovo and Kelly Walsh descended to the "Western Pool" of the Challenger Deep in the Deep-Submergence Vehicle ''Limiting Factor'' spending four hours at the bottom. They reached a maximum depth of {{Convert|10923|m|ft|abbr=on}}. Kelly Walsh is the son of the ''[[Trieste (bathyscaphe)|Trieste's]]'' captain [[Don Walsh]] who descended there in 1960 with [[Jacques Piccard]].<ref>{{cite news |url=https://www.bbc.com/news/science-environment-53112621 |title=Mariana Trench: Don Walsh's son repeats historic ocean dive |work=bbc.com |date=20 June 2020 |access-date=21 June 2020 |archive-date=23 June 2020 |archive-url=https://web.archive.org/web/20200623122434/https://www.bbc.com/news/science-environment-53112621 |url-status=live }}</ref><ref>{{cite web|url=https://caladanoceanic.com/wp-content/uploads/2020/06/EYOS-Expeditions-Kelly-Walsh-dive-20th-June-2020.pdf |archive-url=https://web.archive.org/web/20201021022307/https://caladanoceanic.com/wp-content/uploads/2020/06/EYOS-Expeditions-Kelly-Walsh-dive-20th-June-2020.pdf |archive-date=2020-10-21 |url-status=live |title=From father to son; the next generation of ocean exploration. Kelly Walsh repeats father's historic dive, 60 years later, on Father's Day weekend |work=caladanoceanic.com |access-date=4 August 2020}}</ref>
On 21 June 2020, Victor Vescovo and Woods Hole Oceanographic Institution researcher Ying-Tsong Lin descended to the "Central Pool" of the Challenger Deep in the Deep-Submergence Vehicle ''Limiting Factor''. They reached a maximum depth of {{Convert|10915|m|ft|abbr=on}} ±{{Convert|4|m|ft|abbr=on}}.<ref>{{cite web |url=https://twitter.com/CaladanOceanic |title=On our latest dive, @WHOI research scientist Dr. Ying-Tsong "Y.-T". Lin joined @VictorVescovo to become, not only the first person born in Taiwan to go to the bottom of the Mariana Trench, but also the first from the Asian continent to do so.work=@CaladanOceanic twitter.com |access-date=24 June 2020 |archive-date=24 June 2020 |archive-url=https://web.archive.org/web/20200624123831/https://twitter.com/caladanoceanic |url-status=live }}</ref><ref>{{cite web |url=https://www.whoi.edu/press-room/news-release/whoi-researcher-dives-to-challenger-deep/ |title=WHOI Researcher Dives to Challenger Deep |work=whoi.edu |access-date=27 June 2020 |archive-date=29 June 2020 |archive-url=https://web.archive.org/web/20200629024615/https://www.whoi.edu/press-room/news-release/whoi-researcher-dives-to-challenger-deep/ |url-status=live }}</ref><ref>{{cite web|url=https://caladanoceanic.com/wp-content/uploads/2020/06/PhaseV_YTRelease_FINAL.pdf |archive-url=https://web.archive.org/web/20201021023506/https://caladanoceanic.com/wp-content/uploads/2020/06/PhaseV_YTRelease_FINAL.pdf |archive-date=2020-10-21 |url-status=live |title=First Taiwanese Native Dives to Challenger Deep |work=caladanoceanic.com |access-date=4 August 2020}}</ref>
On 26 June 2020 Victor Vescovo and [[Jim Wigginton]] descended to the "Eastern Pool" of the Challenger Deep in the Deep-Submergence Vehicle ''Limiting Factor''.<ref>{{cite web |url=https://tritonsubs.com/2020/07/01/8773/ |title=Caladan Oceanic Revisits Challenger Deep in Month-Long Dive Series |work=tritonsubs.com |access-date=29 July 2020 |archive-date=29 July 2020 |archive-url=https://web.archive.org/web/20200729135248/https://tritonsubs.com/2020/07/01/8773/ |url-status=dead }}</ref>

====2020 – ''Fendouzhe''====
{{main|Striver (bathyscaphe)}}

[[File:The chinese submersible Fendouzhe aboard its mother ship Tan Suo Yi Hao.jpg|thumb|upright|''Fendouzhe'' aboard its mother ship ''Tan Suo Yi Hao'']]

''Fendouzhe'' (奋斗者, ''Striver'') is a manned [[China|Chinese]] deep-sea submersible developed by the China Ship Scientific Research Center (CSSRC). Between 10 October and 28 November, 2020, it carried out thirteen dives in the Mariana Trench as part of a test programme. Of these, eight led to depths of more than {{convert|10000|m|ft|0|abbr=on}}. On 10 November 2020, the bottom of the Challenger Deep was reached by ''Fendouzhe'' with three Chinese scientists (Zhāng Wěi 张伟 [pilot], Zhào Yáng 赵洋, and Wáng Zhìqiáng 王治强) onboard whilst live-streaming the descent to a reported depth of {{convert|10909|m|ft|0|abbr=on}}.<ref name="Fendouze3">{{Cite web|title=Chinese submarine reaches the deepest place on Earth|url=https://www.livescience.com/chinese-submarine-record-dive.html|access-date=2021-04-26|website=interestingengineering.com|date=30 November 2020 |language=en-US|archive-date=26 April 2021|archive-url=https://web.archive.org/web/20210426104528/https://www.livescience.com/chinese-submarine-record-dive.html|url-status=live}}</ref><ref name="Fendouze1">{{Cite web|title=Chinese Submersible "Fendouzhe" Descended to Earth's Deepest Oceanic Trench|url=https://www.sciencetimes.com/articles/28350/20201121/chinese-submersible-fendouzhe-descended-earths-deepest-oceanic-trench.htm|access-date=2021-04-26|website=sciencetimes.com|date=21 November 2020 |language=en-US|archive-date=16 September 2021|archive-url=https://web.archive.org/web/20210916190150/https://www.sciencetimes.com/articles/28350/20201121/chinese-submersible-fendouzhe-descended-earths-deepest-oceanic-trench.htm|url-status=live}}</ref> This makes the '' Fendouzhe '' the fourth manned submersible vehicle achieving a successful descent. The pressure hull of ''Fendouzhe'', made from a newly developed titanium alloy, offers space for three people in addition to technical equipment.<ref name="Fendouze2">{{Cite web|title=Chinese Manned Submersible Reaches Deepest Part of Mariana Trench|url=https://interestingengineering.com/chinese-manned-submersible-reaches-deepest-part-of-mariana-trench|access-date=2021-04-26|website=interestingengineering.com|date=26 November 2020 |language=en-US|archive-date=26 April 2021|archive-url=https://web.archive.org/web/20210426104525/https://interestingengineering.com/chinese-manned-submersible-reaches-deepest-part-of-mariana-trench|url-status=live}}</ref> ''Fendouzhe'' is equipped with cameras made by the Norwegian manufacturer Imenco.<ref name="Fendouze8">{{Cite web|title=Imenco in the worlds deepest waters|url=https://imenco.no/imenco-in-the-worlds-deepest-waters|access-date=2021-04-28|website=imenco.no|date=23 November 2020 |language=en-US|archive-date=28 April 2021|archive-url=https://web.archive.org/web/20210428100327/https://imenco.no/imenco-in-the-worlds-deepest-waters|url-status=live}}</ref>
According to Ye Cong 叶聪, the chief designer of the submersible, China's goals for the dive aren't just scientific investigation but also the future use of deep-sea seabed resources.<ref name="Fendouze6">{{Cite web|title=China breaks national record for Mariana Trench manned-dive amid race for deep sea resources|url=https://edition.cnn.com/2020/11/11/asia/china-record-dive-mariana-trench-intl-hnk/index.html|access-date=2021-04-26|website=cnn.com|date=11 November 2020 |language=en-US|archive-date=12 April 2021|archive-url=https://web.archive.org/web/20210412034036/https://edition.cnn.com/2020/11/11/asia/china-record-dive-mariana-trench-intl-hnk/index.html|url-status=live}}</ref><ref name="Fendouze7">{{Cite news|title=Chinese submarine sends first live video back from the bottom of the Mariana Trench|url=https://www.abc.net.au/news/2020-11-29/chinese-sub-reaches-deepest-ocean-trench-mariana-fendouzhe/12932462|access-date=2021-04-27|newspaper=ABC News|date=29 November 2020 |language=en-US|archive-date=24 July 2021|archive-url=https://web.archive.org/web/20210724015107/https://www.abc.net.au/news/2020-11-29/chinese-sub-reaches-deepest-ocean-trench-mariana-fendouzhe/12932462|url-status=live}}</ref>

====2021 – ''Ring of Fire 2 Expedition / DSV Limiting Factor''====
{{main|DSV Limiting Factor}}
On 28 February 2021 Caladan Oceanic's "Ring of Fire 2" expedition arrived over the Challenger Deep and conducted manned descents and lander deployments into the Challenger Deep.<ref>{{cite web| url = https://twitter.com/VictorVescovo| title = Victor Vescovo @ twitter| access-date = 21 June 2020| archive-date = 20 March 2021| archive-url = https://web.archive.org/web/20210320061916/https://twitter.com/VictorVescovo| url-status = live}}</ref> At the start the (uncrewed) ultra-deep-sea lander ''Skaff'' was deployed to collect water column data by CTD for the expedition. The effects of the Pacific subducting plate crashing into the Philippine Plate was among the things researched onsite.
On 1 March 2021, the first manned descent to the eastern pool was made by Victor Vescovo and [[Richard Garriott]].<ref>{{cite web| url = https://twitter.com/RichardGarriott/status/1366326951372328962| title = Richard Garriott @ twitter| access-date = 2 March 2021| archive-date = 1 March 2021| archive-url = https://web.archive.org/web/20210301095935/https://twitter.com/RichardGarriott/status/1366326951372328962| url-status = live}}</ref> Garriott became the 17th person to descend to the bottom.<ref>{{cite web |url=https://www.mirror.co.uk/news/uk-news/history-making-brit-explorer-dives-23593598 |title=Brit spaceman's incredible pictures from the bottom the Earth – including selfie |work=mirror.co.uk |date=2 March 2021 |access-date=3 March 2021 |archive-date=2 March 2021 |archive-url=https://web.archive.org/web/20210302195003/https://www.mirror.co.uk/news/uk-news/history-making-brit-explorer-dives-23593598 |url-status=live }}</ref><ref name="collectspace.com">{{cite web |url=http://www.collectspace.com/news/news-030321a-astronaut-garriott-dive-challenger-deep.html |title=Astronaut-explorer sets records on dive to deepest point on Earth |work=collectspace.com |access-date=6 March 2021 |archive-date=5 March 2021 |archive-url=https://web.archive.org/web/20210305083455/http://www.collectspace.com/news/news-030321a-astronaut-garriott-dive-challenger-deep.html |url-status=live }}</ref>
On 2 March 2021, a descent to the eastern pool was made by Victor Vescovo and [[Michael Dubno]].<ref name="collectspace.com"/><ref>{{cite web| url = https://twitter.com/hashtag/venturetothedeep?src=hashtag_click| title = VentureToTheDeep @ twitter| access-date = 15 March 2021| archive-date = 24 December 2021| archive-url = https://web.archive.org/web/20211224185749/https://twitter.com/hashtag/venturetothedeep?src=hashtag_click| url-status = live}}</ref>
On 5 March a descent to the eastern pool was made by Victor Vescovo and [[Hamish Harding]].<ref>{{cite web |url=https://www.gulftoday.ae/news/2021/03/05/dubai-resident-hamish-harding-explores-ocean-deepest-point-challenger-deep |title=Dubai resident Hamish Harding explores ocean's deepest point 'Challenger Deep' in record-breaking attempt |work=gulftoday.ae |access-date=6 March 2021 |format=video |archive-date=5 March 2021 |archive-url=https://web.archive.org/web/20210305210749/https://www.gulftoday.ae/news/2021/03/05/dubai-resident-hamish-harding-explores-ocean-deepest-point-challenger-deep |url-status=live }}</ref> They traversed the bottom of Challenger Deep.<ref>{{cite web| url = https://www.facebook.com/ActionAviationChairman/| title = Hamish Harding @ facebook| website = [[Facebook]]}}</ref><ref>{{cite web| url = https://twitter.com/actionaviation0| title = Hamish Harding @ twitter| access-date = 6 March 2021| archive-date = 20 March 2021| archive-url = https://web.archive.org/web/20210320062151/https://twitter.com/ActionAviation0| url-status = live}}</ref>
On 11 March 2021 a descent to the Western Pool was made by Victor Vescovo and marine botanist [[Nicole Yamase]].<ref>{{cite web| url = https://www.facebook.com/BlueProsperityMicronesia/posts/257836152625175 |archive-url=https://ghostarchive.org/iarchive/facebook/113462413729217/257836152625175 |archive-date=2022-02-25 |url-access=limited| title = Blue Prosperity Micronesia @ Facebook|website=[[Facebook]] }}{{cbignore}}</ref>
On 13 April 2021 a descent was made by deep water submersible operations expert [[Rob McCallum]] and Tim Macdonald who piloted the dive.<ref>{{cite web |url=https://www.stuff.co.nz/science/124823189/historymaking-109km-anzac-dive-to-the-bottom-of-the-mariana-trench |title=History-making 10.9km 'Anzac Dive' to the bottom of the Mariana Trench |work=stuff.co.nz |date=13 April 2021 |access-date=17 April 2021 |archive-date=16 April 2021 |archive-url=https://web.archive.org/web/20210416222540/https://www.stuff.co.nz/science/124823189/historymaking-109km-anzac-dive-to-the-bottom-of-the-mariana-trench |url-status=live }}</ref><ref name="ANZAC Dive">{{Cite web|title='The ANZAC Dive': Australian, New Zealander Dive To Challenger Deep – DeeperBlue.com|url=https://www.deeperblue.com/the-anzac-dive-australian-new-zealander-dive-to-challenger-deep/|access-date=2021-04-10|website=www.deeperblue.com|language=en-US|archive-date=10 April 2021|archive-url=https://web.archive.org/web/20210410024556/https://www.deeperblue.com/the-anzac-dive-australian-new-zealander-dive-to-challenger-deep/|url-status=live}}</ref><ref name="challengeranzac">{{Cite web|title=Challenger Deep ANZAC Expedition|url=https://caladanoceanic.com/expeditions/challengeranzac/|access-date=2021-04-18|website=caladanoceanic.com|language=en-US|archive-date=18 April 2021|archive-url=https://web.archive.org/web/20210418130115/https://caladanoceanic.com/expeditions/challengeranzac/|url-status=live}}</ref>
A 2021 descent with a Japanese citizen is planned.<ref name="challengerjapan">{{Cite web|title=Challenger Deep Japanese Expedition|url=https://caladanoceanic.com/expeditions/challengerjapan/|access-date=2021-04-18|website=caladanoceanic.com|language=en-US|archive-date=18 April 2021|archive-url=https://web.archive.org/web/20210418130117/https://caladanoceanic.com/expeditions/challengerjapan/|url-status=dead}}</ref>
All manned descents were conducted in the Deep-Submergence Vehicle ''[[Triton Submarines|DSV Limiting Factor]]''.

====2022 - ''Ring of Fire 3 Expedition / DSV Limiting Factor''====
{{main|DSV Limiting Factor}}
{{multiple image
   | width     = 207
   | footer    = 
   | image1    = Dr Dawn Wright and CDR Victor Vescovo Challenger Deep Dive 071222 Western Pool-1.jpg
   | alt21     =
   | caption1  = <small>Dawn Wright and Victor Vescovo aboard DSV ''Limiting Factor'' during their July 2022 dive into the Western Pool</small>
   | image2    = Challenger Deep Dive 071222 by V Vescovo in DSV Limiting Factor - Southern Wall of Western Pool.jpg
   | alt2      =
   | caption2  = <small>Southern wall of the Western Pool</small>
  }}

In July 2022 for the fourth consecutive year, Caladan Oceanic's deep submergence system, consisting of the deep submersible DSV ''Limiting Factor'' supported by the mother ship DSSV ''Pressure Drop'', returned to the Challenger Deep for dives into the Challenger Deep.<ref>[https://www.facebook.com/pg/Dssvpressuredrop/posts/ @Dssvpressuredrop on Twitter]</ref>
In early July 2022, Victor Vescovo was joined by Aaron Newman as a mission specialist for a dive into the Central pool.<ref>{{cite tweet|number=1544086485556658179|user=VictorVescovo|title=Completed a dive into the Challenger Deep, Central Pool with Aaron Newman...<!-- full text of tweet that Twitter returned to the bot (excluding links) added by TweetCiteBot. This may be better truncated or may need expanding (TW limits responses to 140 characters) or case changes. --> |accessdate=22 July 2022|date=5 July 2022}}</ref> On 5 July 2022, Tim Macdonald as pilot and Jim Kitchen as mission specialist for a dive into the Eastern pool.<ref>{{cite tweet|number=1545243188692193281|user=VictorVescovo|title=A dive at Challenger Deep (CD) was completed on July 5th with Tim Macdonald as pilot and Jim Kitchen as mission specialist...<!-- full text of tweet that Twitter returned to the bot (excluding links) added by TweetCiteBot. This may be better truncated or may need expanding (TW limits responses to 140 characters) or case changes. --> |accessdate=22 July 2022|date=8 July 2022}}</ref> On 8 July 2022 Victor Vescovo was joined by [[Dylan Taylor (executive)|Dylan Taylor]] as mission specialist for a dive into the Eastern pool.<ref>{{cite tweet|number=1545244724612694017|user=VictorVescovo|title=Completed another dive into the western, unvisited, area of the Eastern Pool of CD with Dylan Taylor...<!-- full text of tweet that Twitter returned to the bot (excluding links) added by TweetCiteBot. This may be better truncated or may need expanding (TW limits responses to 140 characters) or case changes. --> |accessdate=22 July 2022|date=8 July 2022}}</ref>
Victor Vescovo (for his 15th dive into the Challenger Deep) was joined by geographer and oceanographer [[Dawn Wright]] as mission specialist on the 12 July 2022 dive to {{convert|10919|m|ft|0|abbr=on}} in the Western Pool.<ref>{{Cite web |url=https://divernet.com/world-dives/deep-sea-mapper-cant-get-much-deeper/ |title=Deep-sea mapper can't get much deeper! divernet.com 15 July 2022 |date=15 July 2022 |access-date=16 July 2022 |archive-date=15 July 2022 |archive-url=https://web.archive.org/web/20220715101107/https://divernet.com/world-dives/deep-sea-mapper-cant-get-much-deeper/ |url-status=live }}</ref><ref>{{cite tweet|number=1547122307646341122|user=VictorVescovo|title=Dr. Dawn Wright and I completed a dive to 10,919m +/- 6m at the bottom of Challenger Deep (my 15th visit), Western Pool.<!-- full text of tweet that Twitter returned to the bot (excluding links) added by TweetCiteBot. This may be better truncated or may need expanding (TW limits responses to 140 characters) or case changes. --> |accessdate=22 July 2022|date=13 July 2022}}</ref> Wright operated the world's first sidescan sonar to ever operate at full-ocean depth to capture detailed imagery along short transects of the southern wall of the Western Pool.<ref>{{cite web |last1=EYOS Expeditions Blog |title=Dawn Wright Successfully Dives Challenger Deep |url=https://www.eyos-expeditions.com/dawn-wright-successfully-dives-challenger-deep/ |website=EYOS Expeditions |date=13 July 2022 |access-date=28 July 2022 |archive-date=14 July 2022 |archive-url=https://web.archive.org/web/20220714010910/https://www.eyos-expeditions.com/dawn-wright-successfully-dives-challenger-deep/ |url-status=live }}</ref><ref>{{cite web |last1=Deep Ocean Search |title=DOS to integrate the world's first 'Full Ocean Depth' side scan sonar |url=http://www.deepoceansearch.com/2021/12/01/dos-to-integrate-the-first-full-ocean-depth-side-scan-sonar-for-caladan-oceanic/ |website=Deep Ocean Search News |date=December 2021 |publisher=Deep Ocean Search |access-date=28 July 2022 |archive-date=18 August 2022 |archive-url=https://web.archive.org/web/20220818041209/http://www.deepoceansearch.com/2021/12/01/dos-to-integrate-the-first-full-ocean-depth-side-scan-sonar-for-caladan-oceanic/ |url-status=live }}</ref>