Splashdown

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.

The American practice came in part because American launch sites are on the coastline and launch primarily over water. Russian launch sites such as Baikonur Cosmodrome are far inland, and most early launch aborts would descend on land.

History

The splashdown method of landing was used for Mercury, Gemini, and Apollo (including Skylab, which used Apollo capsules) missions, and is used for Artemis missions. Soyuz 23 unintentionally landed on a freezing lake with slushy patches of ice during a snowstorm.Archived at Ghostarchive and the Wayback Machine:

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 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 and escorted safely inside a Mobile Quarantine Facility.

Both the SpaceX Dragon 1 and Dragon 2 capsules were designed to use the splashdown method of landing. 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.

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.

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. 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. 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.

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 . 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.

Launch vehicles

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.

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.

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 completed their first booster recovery.

List of spacecraft splashdowns Crewed spacecraft # Spacecraft Agency Landing date Coordinates Recovery ship Miss distance (km) Reference 1 Freedom 7 NASA May 5, 1961 Ezell (1988) p. 143 2 Liberty Bell 7 NASA July 21, 1961 Ezell (1988) p. 144 3 Friendship 7 NASA February 20, 1962 (USS Randolph**) 74 Ezell, Volume II, p. 145 4 Aurora 7 NASA May 24, 1962 (**) 400 Ezell, Volume II, p. 146 5 Sigma 7 NASA October 3, 1962 7.4 Ezell, Volume II, p. 147 6 Faith 7 NASA May 16, 1963 USS Kearsarge 8.1 Ezell, Volume II, p. 148 7 Gemini 3 NASA March 23, 1965 USS Intrepid 111 Ezell, Volume II, p. 159 8 Gemini 4 NASA June 7, 1965 81 Ezell, Volume II, p. 160 9 Gemini 5 NASA August 29, 1965 USS Lake Champlain 270 Ezell, Volume II, p. 161 10 Gemini 7 NASA December 18, 1965 USS Wasp 12 Ezell, Volume II, p. 162 11 Gemini 6A NASA December 16, 1965 USS Wasp 13 Ezell, Volume II, p. 163 12 Gemini 8 NASA March 17, 1966 (**) 2 Ezell, Volume II, p. 164 13 Gemini 9A NASA June 6, 1966 USS Wasp 0.7 Ezell, Volume II, p. 165 14 Gemini 10 NASA July 21, 1966 6 Ezell, Volume II, p. 166 15 Gemini 11 NASA September 15, 1966 5 Ezell, Volume II, p. 167 16 Gemini 12 NASA November 15, 1966 USS Wasp 5 Ezell, Volume II, p. 168 17 Apollo 7 NASA October 22, 1968 3 Ezell, Volume II, p. 188 18 Apollo 8 NASA December 27, 1968 2 Ezell, Volume II, p. 189 19 Apollo 9 NASA March 13, 1969 USS Guadalcanal 5 Ezell, Volume III, p. 83Orloff, p. 58 20 Apollo 10 NASA May 26, 1969 2.4 Ezell, Volume III, p. 84Orloff, p. 78 21 Apollo 11 NASA July 24, 1969 3.13 Ezell, Volume III, p. 85Orloff, p. 98 22 Apollo 12 NASA November 24, 1969 USS Hornet 3.7 Ezell, Volume III, p. 86Orloff, p. 120 23 Apollo 13 NASA April 17, 1970 1.85 Ezell, Volume III, p. 87Orloff, p. 143 24 Apollo 14 NASA February 9, 1971 1.1 Ezell, Volume III, p. 88Orloff, p. 168 25 Apollo 15 NASA August 7, 1971 1.85 Ezell, Volume III, p. 89Orloff, p. 197 26 Apollo 16 NASA April 27, 1972 0.55 Ezell, Volume III, p. 91Orloff, p. 225 27 Apollo 17 NASA December 19, 1972 USS Ticonderoga 1.85 Ezell, Volume III, p. 92Orloff, p. 251 28 Skylab 2 NASA June 22, 1973 USS Ticonderoga Ezell, Volume III, p. 104 29 Skylab 3 NASA September 25, 1973 USS New Orleans Ezell, Volume III, p. 105 30 Skylab 4 NASA February 8, 1974 USS New Orleans 31 Apollo CSM-111 NASA July 24, 1975 USS New Orleans 1.3 Ezell, Volume III, p. 112"ASTP Apollo Miss Distance", ASTP Summary Science Report - Mission Description p. 36, 32 Soyuz 23 USSR October 16, 1976 Lake Tengiz Mi-8 helicopter 33 Crew Dragon Demo-2 SpaceX August 2, 2020 GO Navigator 33 Crew Dragon Crew-1 SpaceX May 2, 2021 GO Navigator 34 Inspiration4 SpaceX September 18, 2021 GO Searcher 35 Crew Dragon Crew-2 SpaceX November 7, 2021 GO Navigator 35 Axiom Mission 1 SpaceX April 25, 2022 Megan36Crew Dragon Crew-3SpaceXMay 6, 2022Shannon37Crew Dragon Crew-4SpaceXOctober 14, 2022Megan38Crew Dragon Crew-5SpaceXMarch 11, 2023Shannon39Axiom Mission 2SpaceXMay 31, 2023Megan40Polaris DawnSpaceXSeptember 15, 202441Artemis IINASAApril 10, 2026USS John P. Murtha

Uncrewed spacecraft Spacecraft Agency Landing date Coordinates Recovery ship Miss distance Jupiter AM-18(Able and Baker) USAF May 28, 1959 N Antigua Island Mercury-Big Joe NASA September 9, 1959 SE Cape Canaveral Mercury-Little Joe 2 Sam The Rhesus Monkey NASA December 4, 1959 SE Wallops Island, Virginia ? km Mercury-Redstone 1A NASA December 19, 1960 SE Cape Canaveral Mercury-Redstone 2 NASA January 31, 1961 SE Cape Canaveral Mercury-Atlas 2 NASA February 21, 1961 SE Cape Canaveral USS Donner Discoverer 25(Corona 9017) USAF June 16, 1961 mid-air recovery missed Mercury-Atlas 4 NASA September 13, 1961 E of Bermuda Mercury-Atlas 5 NASA November 29, 1961 SE of Bermuda ? km Gemini 2 NASA January 19, 1965 downrange from KSC USS Lake Champlain "Gemini 2 Distance traveled, Landing Point, Miss Distance", Manned Space Flight Network Performance Analysis for the GT-2 Mission; Pg V - Distance traveled, Page 21 - Landing Point, Miss Distance, (NASA X-552-65-204) AS-201 NASA February 26, 1966 downrange from KSC USS Boxer ? km AS-202 NASA August 25, 1966 southwest of Wake Island USS Hornet ? km Gemini 2-MOL USAF November 3, 1966 SE KSC near Ascension Island Apollo 4 NASA November 9, 1967 Apollo 6 NASA April 4, 1968 USS Okinawa ? km Zond 5 USSR September 21, 1968 USSR recovery naval vessel and "Zond 5, Landing Point, Miss Distance" , NASA Solar System Exploration - Zond 5, Landing Point, Miss Distance. Zond 8 USSR October 27, 1970 SE of the Chagos Archipelago, Indian Ocean USSR recovery ship 24 km"Zond 8, Landing Point" , NASA Solar System Exploration - Zond 8, Splashdown area. Cosmos 1374 USSR June 4, 1982 S of Cocos Islands, Indian Ocean USSR recovery ship ? km Cosmos 1445 USSR March 15, 1983 S of Cocos Islands, Indian Ocean USSR recovery ship ? km Cosmos 1517 USSR December 27, 1983 near Crimea, Black Sea USSR recovery ship ? km Cosmos 1614 USSR December 19, 1984 ? km W of the Crimea, Black Sea USSR recovery ship ? km COTS Demo Flight 1 SpaceX December 8, 2010 west of Baja California, Mexico, Pacific Ocean ? Dragon C2+ SpaceX May 31, 2012 ? ? CRS SpX-1 SpaceX October 28, 2012 ? American Islander ? CRS SpX-2 SpaceX March 27, 2013 ? American Islander ? Exploration Flight Test 1 NASA December 5, 2014 , west of Baja California Crew Dragon Demo-1 SpaceX March 8, 2019 In the Gulf of Mexico, off the coast of Pensacola, Florida GO Searcher SpaceX CRS-21 SpaceX January 14, 2020 In the Gulf of Mexico, off the coast of Tampa, Florida GO Navigator Artemis I NASA December 11, 2022 Pacific Ocean, west of Baja California USS Portland 4 nm IFT-4 SpaceX June 6, 2024 Indian Ocean IFT-5 SpaceX October 13, 2024 Indian Ocean IFT-6 SpaceX November 19, 2024 Indian Ocean IFT-10 SpaceX August 26, 2025 Indian Ocean IFT-11 SpaceX October 13, 2025 Indian OceanIFT-12SpaceXMay 22, 2026Indian OceanIFT-13SpaceXJuly 24, 2026Indian OceanGo australis, Normad ranger, Skimmer Tide and Boskalis Forte

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