splashdown

{{short description|Method of landing a spacecraft by parachute in a body of water}}

{{For-multi|aircraft landing on water|Water landing|other uses|Splashdown (disambiguation)}}

File:Apollo 15 splashdown.jpg makes contact with the Pacific Ocean.]]

Image:Splashdown.png splashdowns of American spacecraft prior to the 21st century]]

Image:Splashdown 2.png splashdowns of American spacecraft]]

Splashdown is the method of landing a spacecraft or launch vehicle in a body of water, usually by parachute. This has been the primary recovery method of American capsules including NASA’s Mercury, Gemini, Apollo and Orion along with the private SpaceX Dragon. It is also possible for the Boeing Starliner, Russian Soyuz, and the Chinese Shenzhou crewed capsules to land in water in case of contingency. NASA recovered the Space Shuttle solid rocket boosters (SRBs) via splashdown, as is done for Rocket Lab's Electron first stage.

As the name suggests, the vehicle parachutes into an ocean or other large body of water. Due to its low density and viscosity, water cushions the spacecraft enough that there is no need for a braking rocket to slow the final descent as is the case with Russian and Chinese crewed space capsules or airbags as is the case with the Starliner.{{cite web |last1=Tous |first1=Marcos |title=The science behind splashdown—aerospace engineer explains how NASA and SpaceX get spacecraft safely back |date = 28 June 2024|url=https://theconversation.com/the-science-behind-splashdown-an-aerospace-engineer-explains-how-nasa-and-spacex-get-spacecraft-safely-back-on-earth-232786 |website=The Conversation |access-date=27 November 2024}}

The American practice came in part because American launch sites are on the coastline and launch primarily over water.{{cite web|url=https://www.nasa.gov/centers/kennedy/launchingrockets/sites.html |title=Launch Services Program Launch Sites |publisher=NASA |date=2009-05-14 |access-date=2020-08-07}} Russian launch sites such as Baikonur Cosmodrome are far inland, and most early launch aborts would descend on land.

History

File:Apollo14 - Landung.jpg returns to Earth, 1971.]]

The splashdown method of landing was used for Mercury, Gemini and Apollo (including Skylab, which used Apollo capsules). Soyuz 23 unintentionally landed on a freezing lake with slushy patches of ice during a snowstorm.Archived at [https://ghostarchive.org/varchive/youtube/20211211/m4pD1L7hedA Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20200516214113/https://www.youtube.com/watch?v=m4pD1L7hedA&attr_tag=BUqbSjTAJRrN1ykS%3A6 Wayback Machine]{{cbignore}}: {{Cite web|url=https://www.youtube.com/watch?v=m4pD1L7hedA|title=The Accidental Spacecraft Splashdown Which Almost Killed Its Crew|via=www.youtube.com}}{{cbignore}}{{cite web|url=http://www.videocosmos.com/soyuz23.shtm |title=Soyuz-23, Lands On A Frozen Lake |publisher=VideoCosmos |access-date=2012-06-21 |url-status=dead |archive-url=https://web.archive.org/web/20120414220743/http://www.videocosmos.com/soyuz23.shtm |archive-date=2012-04-14 }}

On early Mercury flights, a helicopter attached a cable to the capsule, lifted it from the water and delivered it to a nearby ship. This was changed after the sinking of Liberty Bell 7. All later Mercury, Gemini and Apollo capsules had a flotation collar (similar to a rubber life raft) attached to the spacecraft to increase their buoyancy. The spacecraft would then be brought alongside a ship and lifted onto deck by crane.

After the flotation collar is attached, a hatch on the spacecraft is usually opened. At that time, some astronauts decide to be hoisted aboard a helicopter for a ride to the recovery ship and some decided to stay with the spacecraft and be lifted aboard ship via crane. All Gemini and Apollo flights (Apollos 7 to 17) used the former, while Mercury missions from Mercury 6 to Mercury 9, as well as all Skylab missions and Apollo-Soyuz used the latter, especially the Skylab flights as to preserve all medical data. During the Gemini and Apollo programs, NASA used {{MV|Retriever}} for the astronauts to practice water egress.

Apollo 11 was America's first Moon landing mission and marked the first time that humans walked on the surface of another planetary body. The possibility of the astronauts bringing pathogens from the Moon back to Earth was remote, but not ruled out. To contain any possible contaminants at the scene of the splashdown, the astronauts donned special Biological Isolation Garments and the outside of the suits were scrubbed prior to the astronauts being hoisted aboard {{USS|Hornet|CV-12|6}} and escorted safely inside a Mobile Quarantine Facility.{{cite web |url=http://www.uss-hornet.org/history/apollo/ |title=Apollo 11 & 12 Recovery |author=Bob Fish |publisher=USS Hornet Museum's website}}

File:SpaceX CRS 25 Splashdown (1920x1080).webm

Both the SpaceX Dragon 1 and Dragon 2 capsules were designed to use the splashdown method of landing.{{efn|Dragon 2 was originally intended to propulsively land using its SuperDraco engines, but this was abandoned except for contingency in case of parachute failure.{{cite web |last1=McRea |first1=Aaron |title=Dragon receives long-planned propulsive landing upgrade after years of development |url=https://www.nasaspaceflight.com/2024/10/dragon-propulsive-landing/ |website=Nasa Spaceflight |access-date=11 November 2024}}}} The original cargo Dragon splashed down in the Pacific Ocean off the coast of Baja California. At the request of NASA, both the crew and cargo variations of the Dragon 2 capsule splash down off the coast of Florida, either in the Atlantic Ocean or the Gulf of Mexico.{{cite news|url=https://spaceflightnow.com/2021/01/12/cargo-dragon-heads-for-splashdown-off-floridas-west-coast/|title=Cargo Dragon heads for splashdown off Florida's west coast|publisher=Spaceflight Now|first=Stephen|last=Clark|date=12 January 2021|access-date=14 January 2021}}{{Cite web|url=https://oig.nasa.gov/docs/IG-18-016.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://oig.nasa.gov/docs/IG-18-016.pdf |archive-date=2022-10-09 |url-status=live|title=AUDIT OF COMMERCIAL RESUPPLY SERVICES TO THE INTERNATIONAL SPACE STATION}}

The early design concept for Orion (then known as the Crew Exploration Vehicle) featured recovery on land using a combination of parachutes and airbags, although it was also designed to make a contingency splashdown if needed. Due to weight considerations, the airbag design concept was dropped for Orion, and it conducts landings via splashdown in the Pacific Ocean off the coast of California.{{cite web|url=http://solarsystem.nasa.gov/news/display.cfm?News_ID=37403 |archive-url=https://web.archive.org/web/20110703185450/http://solarsystem.nasa.gov/news/display.cfm?News_ID=37403 |url-status=dead |archive-date=2011-07-03 |title=Solar System Exploration: News & Events: News Archive: NASA Announces Key Decision For Next Deep Space Transportation System |publisher=Solarsystem.nasa.gov |date=2011-05-24 |access-date=2012-06-21}}

Disadvantages

Perhaps the most dangerous aspect is the possibility of the spacecraft flooding and sinking. For example, when the hatch of Gus Grissom's Liberty Bell 7 capsule blew prematurely, the capsule sank and Grissom almost drowned. Since the spacecraft's flooding will occur from a location in its hull where it ruptures first, it is important to determine the location on the hull that experiences the highest loading.{{cite journal|last=Jain|first=U.|display-authors=et al.|journal=Journal of Fluid Mechanics|date=2021|volume=938|issue=4|title=Air entrapment and its effect on pressure impulses in the slamming of a flat disc on water |page= A31 |doi=10.1017/jfm.2021.846| arxiv=2012.10137|bibcode=2021JFM...928A..31J }} This location along the impacting side is determined by the surrounding `air cushion' layer, which deforms the water surface before the moment of impact, and results in a non-trivial geometry of the liquid surface during first touch-down.{{cite journal|last=Jain|first=U.|display-authors=et al.|journal=Physical Review Fluids|date=2021|volume=6|issue=4|title=Air-cushioning effect and Kelvin-Helmholtz instability before the slamming of a disk on water |page= L042001 |doi=10.1103/PhysRevFluids.6.L042001|arxiv= 2106.09551|bibcode=2021PhRvF...6d2001J }}{{cite journal|last=Verhagen|first=J.H.G|journal= Journal of Ship Research|year=1967|title=The Impact of a Flat Plate on a Water Surface|volume=11 |issue=4 |pages=211–223 |doi=10.5957/jsr.1967.11.4.211 |url=https://archive.org/details/Verhagen1967}}{{cite journal|last= Asryan |first=N.G.|journal= Izv. Akad. Nauk Arm. SSR Mekh|date=1972|title=Solid plate impact on surface of incompressible fluid in the presence of a gas layer between them|url=https://archive.org/details/Asrian1972_201803}} Soyuz 23 was dragged under a frozen lake by its parachutes. The crew became incapacitated by carbon dioxide and were rescued after a nine-hour recovery operation.{{cite web |title=Carbon Dioxide (CO2) OCHMO-TB-004 Rev C |url=https://www.nasa.gov/wp-content/uploads/2023/12/ochmo-tb-004-carbon-dioxide.pdf |website=NASA |access-date=27 November 2024}}

If the capsule comes down far from any recovery forces, the crew may be stranded at sea for an extended period of time. As an example, Scott Carpenter in Aurora 7 overshot the assigned landing zone by {{convert|400|km|sp=us}}. These recovery operation mishaps can be mitigated by placing several vessels on standby in different locations, but this can be an expensive option.

Exposure to salt water can have adverse effects on vehicles intended for reuse, such as Dragon.{{cite web |work = NASA|page=4-5|title=A FRAMEWORK FOR ASSESSING THE REUSABILITY OF HARDWARE (REUSABLE ROCKET ENGINES |url=https://ntrs.nasa.gov/api/citations/20170000606/downloads/20170000606.pdf |access-date=11 November 2024}}

Launch vehicles

File:Freedom Star SRB recovery.jpg after splashing down on STS-133]]

Some reusable launch vehicles recover components via splashdown. This was first seen with the Space Shuttle SRBs, with STS-1 launching in 1981. Out of 135 launches, NASA recovered all but two sets of SRBs.{{cite web |last1=Gebhardt |first1=Chris |date=8 July 2012|title=One year on – Review notes superb performance of STS-135's SRBs |url=https://www.nasaspaceflight.com/2012/07/final-flight-superb-performance-sts-135s-srbs/ |website=NASA Spaceflight |access-date=27 November 2024}}

SpaceX has conducted propulsive splashdowns of the Falcon 9 first stage, Super Heavy booster, and Starship spacecraft. These vehicles are designed to land on land or modified barges and do not always survive intact after tipping over in the water; SpaceX has mainly conducted propulsive splashdowns for development flights. After the launch of CRS-16, the booster experienced a control issue and splashed down in the ocean instead of making an intended landing at Landing Zone 1.{{cite web |last1=Bergin |first1=Chris |date=13 January 2019|title=CRS-16 Dragon returns to Earth following ISS departure |url=https://www.nasaspaceflight.com/2019/01/crs-16-dragon-departs-iss-return-journey/ |website=NASA Spaceflight |access-date=27 November 2024}}

Rocket Lab intended to catch the first stage of their Electron rocket with a helicopter as it descended under parachute, but abandoned this idea in favor of parachute splashdown. In 2020, Rocket Lab made their first booster recovery.{{cite web |last1=Coldewey |first1=Devin |title=Rocket Lab makes its first booster recovery after successful launch |url=https://techcrunch.com/2020/11/19/rocket-lab-makes-its-first-booster-recovery-after-successful-launch/ |website=TechCrunch |date=19 November 2020|access-date=27 November 2024}}

List of spacecraft splashdowns

=Crewed spacecraft=

class="wikitable"
# ! Spacecraft ! Agency ! Landing date ! Coordinates ! Recovery ship ! Miss distance (km) ! Reference
1 \| Freedom 7 \| NASA \| May 5, 1961 \| {{coord\|27\|13.7\|N\|75\|53\|W\|name=Freedom 7}} \| {{USS\|Lake Champlain\|CV-39\|6}} \| {{convert\|5.6\|km\|mi\|abbr=on}} \|Ezell (1988) p. 143
2 \| Liberty Bell 7 \| NASA \| July 21, 1961 \| {{coord\|27\|32\|N\|75\|44\|W\|name=Liberty Bell 7}} \| {{USS\|Randolph\|CV-15\|6}} \| {{convert\|9.3\|km\|mi\|abbr=on}} \|Ezell (1988) p. 144
3 \| Friendship 7 \| NASA \| February 20, 1962 \| {{coord\|21\|26\|N\|68\|41\|W\|name=Friendship 7}} \| {{USS\|Noa\|DD-841\|6}} (USS Randolph**) \| 74 \|Ezell, Volume II, p. 145
4 \| Aurora 7 \| NASA \| May 24, 1962 \| {{coord\|19\|27\|N\|63\|59\|W\|name=Aurora 7}} \| {{USS\|John R. Pierce\|DD-753\|6}} ({{USS\|Intrepid\|CV-11\|6}}**) \| 400 \|Ezell, Volume II, p. 146
5 \| Sigma 7 \| NASA \| October 3, 1962 \| {{coord\|32\|06\|N\|174\|28\|W\|name=Sigma 7}} \| {{USS\|Kearsarge\|CV-33\|6}} \| 7.4 \|Ezell, Volume II, p. 147
6 \| Faith 7 \| NASA \| May 16, 1963 \| {{coord\|27\|20\|N\|176\|26\|W\|name=Faith 7}} \| USS Kearsarge \| 8.1 \|Ezell, Volume II, p. 148
7 \| Gemini 3 \| NASA \| March 23, 1965 \| {{coord\|22\|26\|N\|70\|51\|W\|name=Gemini 3}} \| USS Intrepid \| 111 \|Ezell, Volume II, p. 159
8 \| Gemini 4 \| NASA \| June 7, 1965 \| {{coord\|27\|44\|N\|74\|11\|W\|name=Gemini 4}} \| {{USS\|Wasp\|CV-18\|6}} \| 81 \|Ezell, Volume II, p. 160
9 \| Gemini 5 \| NASA \| August 29, 1965 \| {{coord\|29\|44\|N\|69\|45\|W\|name=Gemini 5}} \| USS Lake Champlain \| 270 \|Ezell, Volume II, p. 161
10 \| Gemini 7 \| NASA \| December 18, 1965 \| {{coord\|25\|25\|N\|70\|07\|W\|name=Gemini 7}} \| USS Wasp \| 12 \|Ezell, Volume II, p. 162
11 \| Gemini 6A \| NASA \| December 16, 1965 \| {{coord\|23\|35\|N\|67\|50\|W\|name=Gemini 6A}} \| USS Wasp \| 13 \|Ezell, Volume II, p. 163
12 \| Gemini 8 \| NASA \| March 17, 1966 \| {{coord\|25\|14\|N\|136\|0\|E\|name=Gemini 8}} \| {{USS\|Leonard F. Mason\|DD-852\|6}} ({{USS\|Boxer\|LPH-4\|6}}**) \| 2 \|Ezell, Volume II, p. 164
13 \| Gemini 9A \| NASA \| June 6, 1966 \| {{coord\|27\|52\|N\|75\|0\|W\|name=Gemini 9A}} \| USS Wasp \| 0.7 \|Ezell, Volume II, p. 165
14 \| Gemini 10 \| NASA \| July 21, 1966 \| {{coord\|26\|45\|N\|71\|57\|W\|name=Gemini 10}} \| {{USS\|Guadalcanal\|LPH-7\|6}} \| 6 \|Ezell, Volume II, p. 166
15 \| Gemini 11 \| NASA \| September 15, 1966 \| {{coord\|24\|15\|N\|70\|0\|W\|name=Gemini 11}} \| {{USS\|Guam\|LPH-9\|6}} \| 5 \|Ezell, Volume II, p. 167
16 \| Gemini 12 \| NASA \| November 15, 1966 \| {{coord\|24\|35\|N\|69\|57\|W\|name=Gemini 12}} \| USS Wasp \| 5 \|Ezell, Volume II, p. 168
17 \| Apollo 7 \| NASA \| October 22, 1968 \| {{coord\|27\|32\|N\|64\|04\|W\|name=Apollo 7}} \| {{USS\|Essex\|CV-9\|6}} \| 3 \|Ezell, Volume II, p. 188
18 \| Apollo 8 \| NASA \| December 27, 1968 \| {{coord\|8\|7.5\|N\|165\|1.2\|W\|name=Apollo 8}} \| {{USS\|Yorktown\|CV-10\|6}} \| 2 \|Ezell, Volume II, p. 189
19 \| Apollo 9 \| NASA \| March 13, 1969 \| {{coord\|23\|15\|N\|67\|56\|W\|name=Apollo 9}} \| USS Guadalcanal \| 5 \|Ezell, Volume III, p. 83Orloff, p. 58
20 \| Apollo 10 \| NASA \| May 26, 1969 \| {{coord\|15\|2\|S\|164\|39\|W\|name=Apollo 10}} \| {{USS\|Princeton\|LPH-5\|6}} \| 2.4 \|Ezell, Volume III, p. 84Orloff, p. 78
21 \| Apollo 11 \| NASA \| July 24, 1969 \| {{coord\|13\|19\|N\|169\|9\|W\|name=Apollo 11}} \| {{USS\|Hornet\|CV-12\|6}} \| 3.13 \|Ezell, Volume III, p. 85Orloff, p. 98
22 \| Apollo 12 \| NASA \| November 24, 1969 \| {{coord\|15\|47\|S\|165\|9\|W\|name=Apollo 12}} \| USS Hornet \| 3.7 \|Ezell, Volume III, p. 86Orloff, p. 120
23 \| Apollo 13 \| NASA \| April 17, 1970 \| {{coord\|21\|38\|S\|165\|22\|W\|name=Apollo 13}} \| {{USS\|Iwo Jima\|LPH-2\|6}} \| 1.85 \|Ezell, Volume III, p. 87Orloff, p. 143
24 \| Apollo 14 \| NASA \| February 9, 1971 \| {{coord\|27\|1\|S\|172\|39\|W\|name=Apollo 14}} \| {{USS\|New Orleans\|LPH-11\|6}} \| 1.1 \|Ezell, Volume III, p. 88Orloff, p. 168
25 \| Apollo 15 \| NASA \| August 7, 1971 \| {{coord\|26\|7\|N\|158\|8\|W\|name=Apollo 15}} \| {{USS\|Okinawa\|LPH-3\|6}} \| 1.85 \|Ezell, Volume III, p. 89Orloff, p. 197
26 \| Apollo 16 \| NASA \| April 27, 1972 \| {{coord\|0\|43\|S\|156\|13\|W\|name=Apollo 16}} \| {{USS\|Ticonderoga\|CV-14\|6}} \| 0.55 \|Ezell, Volume III, p. 91Orloff, p. 225
27 \| Apollo 17 \| NASA \| December 19, 1972 \| {{coord\|17\|53\|S\|166\|7\|W\|name=Apollo 17}} \| USS Ticonderoga \| 1.85 \|Ezell, Volume III, p. 92Orloff, p. 251
28 \| Skylab 2 \| NASA \| June 22, 1973 \| {{coord\|24\|45\|N\|127\|2\|W\|name=Skylab 2}} \| USS Ticonderoga \| \|Ezell, Volume III, p. 104
29 \| Skylab 3 \| NASA \| September 25, 1973 \| {{coord\|30\|47\|N\|120\|29\|W\|name=Skylab 3}} \| USS New Orleans \| \|Ezell, Volume III, p. 105
30 \| Skylab 4 \| NASA \| February 8, 1974 \| {{coord\|31\|18\|N\|119\|48\|W\|name=Skylab 4}} \| USS New Orleans \| \|
31 \| Apollo CSM-111 \| NASA \| July 24, 1975 \| {{coord\|22\|N\|163\|W\|name=ASTP Apollo}} \| USS New Orleans \| 1.3 \|Ezell, Volume III, p. 112[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19780009147_1978009147.pdf "ASTP Apollo Miss Distance"], ASTP Summary Science Report - Mission Description p. 36, {{Webarchive\|url=https://web.archive.org/web/20100214223755/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19780009147_1978009147.pdf \|archive-url=https://ghostarchive.org/archive/20221009/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19780009147_1978009147.pdf \|archive-date=2022-10-09 \|url-status=live \|date=2010-02-14 }}
32 \| Soyuz 23 \| USSR \| October 16, 1976 \| Lake Tengiz \| Mi-8 helicopter \| \|{{cite news \|url=https://www.newspapers.com/article/the-birmingham-news-cosmonauts-land-in-l/171148700/ \|title=Cosmonauts land in lake in snowstorm \|newspaper=The Birmingham News \|date=October 18, 1976 \|agency=UPI \|via=newspapers.com}}
33 \| Crew Dragon Demo-2 \| SpaceX \| August 2, 2020 \| {{coord\|29\|48\|N\|87\|30\|W\|name=Crew Dragon Demo-2}} \| GO Navigator \| \|{{cite news\|url=https://www.nytimes.com/2020/08/02/science/spacex-nasa-return.html?smtyp=cur&smid=tw-nytimes \|title=NASA Astronauts in SpaceX Capsule Make First Water Landing Since 1975 \|newspaper=The New York Times \|date=August 2, 2020}}
33 \| Crew Dragon Crew-1 \| SpaceX \| May 2, 2021 \| {{coord\|29\|32\|N\|86\|11\|W\|name=Crew Dragon Crew-1}} \| GO Navigator \| \|{{cite news\|url=https://www.orlandosentinel.com/space/os-bz-spacex-crew1-astronaut-splashdown-20210502-3ujhszbeejhxtbmb55lynkzcc4-story.html \|title=SpaceX Dragon splashes down in Gulf of Mexico, bringing 4 astronauts home \|newspaper=Orlando Sentinel \|date=May 2, 2021}}
34 \| Inspiration4 \| SpaceX \| September 18, 2021 \| \| GO Searcher \| \|{{cite news\|url=https://www.cnn.com/2021/09/18/tech/spacex-inspiration4-splashdown-scn/index.html \|title=SpaceX capsule returns four civilians from orbit, capping off first tourism mission \|website=CNN.com \|date=September 18, 2021}}
35 \| Crew Dragon Crew-2 \| SpaceX \| November 7, 2021 \| \| GO Navigator \| \|
35 \| Axiom Mission 1 \| SpaceX \| April 25, 2022 \| \| Megan \| \|
36 \|Crew Dragon Crew-3 \|SpaceX \|May 6, 2022 \| \|Shannon \| \|{{Cite web \|author=Jackie Wattles \|title=SpaceX's wildly busy year continues with astronaut splashdown \|url=https://www.cnn.com/2022/05/06/tech/spacex-crew-3-nasa-splashdown-scn/index.html \|access-date=2022-05-06 \|website=CNN}}
37 \|Crew Dragon Crew-4 \|SpaceX \|October 14, 2022 \| \|Megan \| \|
38 \|Crew Dragon Crew-5 \|SpaceX \|March 11, 2023 \| \|Shannon \| \|
39 \|Axiom Mission 2 \|SpaceX \|May 31, 2023 \| \|Megan \| \|
40 \|Polaris Dawn \|SpaceX \|Sep 15, 2024 \| \| \| \|

class="wikitable"

! Spacecraft

! Agency

! Landing date

! Coordinates

! Recovery ship

! Miss distance (km)

! Reference

splashdown

History

Disadvantages

Launch vehicles

List of spacecraft splashdowns

=Crewed spacecraft=

=Uncrewed spacecraft=

Gallery

See also

Notes

References

Bibliography

External links