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.[1]
The American practice came in part because American launch sites are on the coastline and launch primarily over water.[2] Russian launch sites such as Baikonur Cosmodrome are far inland, and most early launch aborts would descend on land.
History
[edit]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.[3][4]
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 and escorted safely inside a Mobile Quarantine Facility.[5]
Both the SpaceX Dragon 1 and Dragon 2 capsules were designed to use the splashdown method of landing.[a] 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.[7][8]
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.[9]
Disadvantages
[edit]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.[10] 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.[11][12][13] 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.[14]
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 400 kilometers (250 mi). 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.[15]
Launch vehicles
[edit]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.[16]
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.[17]
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.[18]
List of spacecraft splashdowns
[edit]Crewed spacecraft
[edit]Uncrewed spacecraft
[edit]Spacecraft | Agency | Landing date | Coordinates | Recovery ship | Miss distance | |
---|---|---|---|---|---|---|
Jupiter AM-18 (Able and Baker) |
USAF | May 28, 1959 | 48 to 96 km (30 to 60 mi) N Antigua Island | USS Kiowa | 16 km (9.9 mi)[64] | |
Mercury-Big Joe | NASA | September 9, 1959 | 2,407 km (1,496 mi) SE Cape Canaveral | USS Strong | 925 km (575 mi)[65] | |
Mercury-Little Joe 2
Sam The Rhesus Monkey |
NASA | December 4, 1959 | 319 km (198 mi) SE Wallops Island, Virginia | USS Borie | ? km[66] | |
Mercury-Redstone 1A | NASA | December 19, 1960 | 378.2 km (235.0 mi) SE Cape Canaveral | USS Valley Forge | 12.9 km (8.0 mi)[67] | |
Mercury-Redstone 2 | NASA | January 31, 1961 | 675.9 km (420.0 mi) SE Cape Canaveral | USS Donner[68] | 209.2 km (130.0 mi)[69] | |
Mercury-Atlas 2 | NASA | February 21, 1961 | 2,293.3 km (1,425.0 mi) SE Cape Canaveral | USS Donner[68] | 20.9 km (13.0 mi)[70] | |
Discoverer 25 (Corona 9017) |
USAF | June 16, 1961 | mid-air recovery missed | |||
Mercury-Atlas 4 | NASA | September 13, 1961 | 257.5 km (160.0 mi) E of Bermuda | USS Decatur | 64.4 km (40.0 mi)[71] | |
Mercury-Atlas 5 | NASA | November 29, 1961 | 804.7 km (500.0 mi) SE of Bermuda | USS Stormes | ? km[72] | |
Gemini 2 | NASA | January 19, 1965 | 16°33.9′N 49°46.27′W / 16.5650°N 49.77117°W 3,423.1 km (2,127.0 mi) downrange from KSC | USS Lake Champlain | 38.6 km (24.0 mi)[73] | |
AS-201 | NASA | February 26, 1966 | 8°11′S 11°09′W / 8.18°S 11.15°W 8,472 km (5,264 mi) downrange from KSC | USS Boxer | ? km[74] | |
AS-202 | NASA | August 25, 1966 | 16°07′N 168°54′E / 16.12°N 168.9°E 804.7 km (500.0 mi) southwest of Wake Island | USS Hornet | ? km[74] | |
Gemini 2-MOL | USAF | November 3, 1966 | 8,149.7 km (5,064.0 mi) SE KSC near Ascension Island | USS La Salle | 11.26 km (7.00 mi)[75] | |
Apollo 4 | NASA | November 9, 1967 | 30°06′N 172°32′W / 30.1°N 172.53°W | USS Bennington | 16 km (9.9 mi)[74] | |
Apollo 6 | NASA | April 4, 1968 | 27°40′N 157°59′W / 27.667°N 157.983°W | USS Okinawa | ? km[74] | |
Zond 5 | USSR | September 21, 1968 | 32°38′S 65°33′E / 32.63°S 65.55°E | USSR recovery naval vessel Borovichy and Vasiliy Golovin | 105 km (65 mi)[76][77] | |
Zond 8 | USSR | October 27, 1970 | 730 km (450 mi) SE of the Chagos Archipelago, Indian Ocean | USSR recovery ship Taman | 24 km[78][79] | |
Cosmos 1374 | USSR | June 4, 1982 | 17°S 98°E / 17°S 98°E 560 km (350 mi) S of Cocos Islands, Indian Ocean | USSR recovery ship | ? km | |
Cosmos 1445 | USSR | March 15, 1983 | 556 km (345 mi) 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 | 800 km (500 mi) west of Baja California, Mexico, Pacific Ocean | ? | 0.8 km (0.50 mi)[80] | |
Dragon C2+ | SpaceX | May 31, 2012 | 26°55′N 120°42′W / 26.92°N 120.7°W | ? | ?[81] | |
CRS SpX-1 | SpaceX | October 28, 2012 | ? | American Islander[82] | ?[83] | |
CRS SpX-2 | SpaceX | March 27, 2013 | ? | American Islander | ?[84] | |
Exploration Flight Test 1 | NASA | December 5, 2014 | 23°36′N 116°24′W / 23.6°N 116.4°W, 443 kilometres (275 mi) west of Baja California | USS Anchorage | ||
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 |
Gallery
[edit]-
The Apollo 15 spacecraft splashed down safely despite a parachute failure. (NASA)
-
Apollo 15 splashdown (NASA)
-
Apollo 11 after splashdown (NASA)
-
Apollo 13 hoisted onto ship (NASA)
-
Gemini water egress training
-
Recovery of the Dragon C2+ on May 31, 2012
-
Recovery of the EFT-1 Orion, December 5, 2014
-
Landing of SpaceX Demo-2, 2 August 2020
See also
[edit]- Apollo program
- Apollo–Soyuz Test Project
- Helicopter 66
- Project Gemini
- Project Mercury
- Skylab
- SpaceX Dragon 1
- SpaceX Dragon 2
- Water landing
- Zond program
Notes
[edit]- ^ Dragon 2 was originally intended to propulsively land using its SuperDraco engines, but this was abandoned except for contingency in case of parachute failure.[6]
References
[edit]- ^ Tous, Marcos (June 28, 2024). "The science behind splashdown—aerospace engineer explains how NASA and SpaceX get spacecraft safely back". The Conversation. Retrieved November 27, 2024.
- ^ "Launch Services Program Launch Sites". NASA. May 14, 2009. Retrieved August 7, 2020.
- ^ Archived at Ghostarchive and the Wayback Machine: "The Accidental Spacecraft Splashdown Which Almost Killed Its Crew" – via www.youtube.com.
- ^ "Soyuz-23, Lands On A Frozen Lake". VideoCosmos. Archived from the original on April 14, 2012. Retrieved June 21, 2012.
- ^ Bob Fish. "Apollo 11 & 12 Recovery". USS Hornet Museum's website.
- ^ McRea, Aaron. "Dragon receives long-planned propulsive landing upgrade after years of development". Nasa Spaceflight. Retrieved November 11, 2024.
- ^ Clark, Stephen (January 12, 2021). "Cargo Dragon heads for splashdown off Florida's west coast". Spaceflight Now. Retrieved January 14, 2021.
- ^ "AUDIT OF COMMERCIAL RESUPPLY SERVICES TO THE INTERNATIONAL SPACE STATION" (PDF). Archived (PDF) from the original on October 9, 2022.
- ^ "Solar System Exploration: News & Events: News Archive: NASA Announces Key Decision For Next Deep Space Transportation System". Solarsystem.nasa.gov. May 24, 2011. Archived from the original on July 3, 2011. Retrieved June 21, 2012.
- ^ Jain, U.; et al. (2021). "Air entrapment and its effect on pressure impulses in the slamming of a flat disc on water". Journal of Fluid Mechanics. 938 (4): A31. arXiv:2012.10137. doi:10.1017/jfm.2021.846.
- ^ Jain, U.; et al. (2021). "Air-cushioning effect and Kelvin-Helmholtz instability before the slamming of a disk on water". Physical Review Fluids. 6 (4): L042001. arXiv:2106.09551. doi:10.1103/PhysRevFluids.6.L042001.
- ^ Verhagen, J.H.G (1967). "The Impact of a Flat Plate on a Water Surface". Journal of Ship Research.
- ^ Asryan, N.G. (1972). "Solid plate impact on surface of incompressible fluid in the presence of a gas layer between them". Izv. Akad. Nauk Arm. SSR Mekh.
- ^ "Carbon Dioxide (CO2) OCHMO-TB-004 Rev C" (PDF). NASA. Retrieved November 27, 2024.
- ^ "A FRAMEWORK FOR ASSESSING THE REUSABILITY OF HARDWARE (REUSABLE ROCKET ENGINES" (PDF). NASA. p. 4-5. Retrieved November 11, 2024.
- ^ Gebhardt, Chris (July 8, 2012). "One year on – Review notes superb performance of STS-135's SRBs". NASA Spaceflight. Retrieved November 27, 2024.
- ^ Bergin, Chris (January 13, 2019). "CRS-16 Dragon returns to Earth following ISS departure". NASA Spaceflight. Retrieved November 27, 2024.
- ^ Coldewey, Devin (November 19, 2020). "Rocket Lab makes its first booster recovery after successful launch". TechCrunch. Retrieved November 27, 2024.
- ^ Ezell (1988) p. 143
- ^ Ezell (1988) p. 144
- ^ Ezell, Volume II, p. 145
- ^ Ezell, Volume II, p. 146
- ^ Ezell, Volume II, p. 147
- ^ Ezell, Volume II, p. 148
- ^ Ezell, Volume II, p. 159
- ^ Ezell, Volume II, p. 160
- ^ Ezell, Volume II, p. 161
- ^ Ezell, Volume II, p. 162
- ^ Ezell, Volume II, p. 163
- ^ Ezell, Volume II, p. 164
- ^ Ezell, Volume II, p. 165
- ^ Ezell, Volume II, p. 166
- ^ Ezell, Volume II, p. 167
- ^ Ezell, Volume II, p. 168
- ^ Ezell, Volume II, p. 188
- ^ Ezell, Volume II, p. 189
- ^ Ezell, Volume III, p. 83
- ^ Orloff, p. 58
- ^ Ezell, Volume III, p. 84
- ^ Orloff, p. 78
- ^ Ezell, Volume III, p. 85
- ^ Orloff, p. 98
- ^ Ezell, Volume III, p. 86
- ^ Orloff, p. 120
- ^ Ezell, Volume III, p. 87
- ^ Orloff, p. 143
- ^ Ezell, Volume III, p. 88
- ^ Orloff, p. 168
- ^ Ezell, Volume III, p. 89
- ^ Orloff, p. 197
- ^ Ezell, Volume III, p. 91
- ^ Orloff, p. 225
- ^ Ezell, Volume III, p. 92
- ^ Orloff, p. 251
- ^ Ezell, Volume III, p. 104
- ^ a b Ezell, Volume III, p. 105
- ^ Ezell, Volume III, p. 112
- ^ "ASTP Apollo Miss Distance", ASTP Summary Science Report - Mission Description p. 36, Archived 2010-02-14 at the Wayback Machine
- ^ "Cosmonauts Land in Lake, Blizzard". The Milwaukee Journal. UPI. October 18, 1976.
- ^ "NASA Astronauts in SpaceX Capsule Make First Water Landing Since 1975". The New York Times. August 2, 2020.
- ^ "SpaceX Dragon splashes down in Gulf of Mexico, bringing 4 astronauts home". Orlando Sentinel. May 2, 2021.
- ^ "SpaceX capsule returns four civilians from orbit, capping off first tourism mission". CNN.com. September 18, 2021.
- ^ Jackie Wattles. "SpaceX's wildly busy year continues with astronaut splashdown". CNN. Retrieved May 6, 2022.
- ^ "Animals Survive 1,500-Mile Ride In Rocket Nose". The Windsor Daily Star. Windsor, Ontario. Associated Press. May 28, 1959.
- ^ "Big Joe Shot". nasa.gov. Retrieved August 9, 2018.
- ^ "Monkey Completes Long Flight Aloft". Ellensburg Daily Record. Ellensburg, Washington. December 4, 1959.
- ^ "Man-In-Space Capsule To Be Closely Studied". The Florence Times. Florence, Alabama. Associated Press. December 20, 1960.
- ^ a b "USS Donner LSD20". Homestead.com. Retrieved June 21, 2012.
- ^ "Chimp Survives Space Shot". The Milwaukee Sentinel. Associated Press. February 1, 1961.
- ^ "Space Capsule Soars 107 Miles High". The Florence Times. Florence, Alabama. Associated Press. February 21, 1961.
- ^ "U.S. Robot Orbited, Returned". Meriden Journal. September 13, 1961.
- ^ "Capsule Trouble Forces Early Landing Of Craft". Toledo Blade. Toledo, Ohio. Associated Press. November 29, 1961.
- ^ "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)
- ^ a b c d Mansfield, Cheryl L. (January 9, 2018). "Apollo-Saturn Unmanned Missions". NASA.
- ^ "Titan 3 Gives Spectacular Space Show". Sarasota Journal. Sarasota, Florida. November 3, 1966.
- ^ Michael Cassutt (2007). Red Moon. Tom Doherty Associates. p. 320. ISBN 978-1-4299-7172-0.
- ^ "Zond 5, Landing Point, Miss Distance" Archived 2011-09-27 at the Wayback Machine, NASA Solar System Exploration - Zond 5, Landing Point, Miss Distance.
- ^ Brian Harvey (2007). Soviet and Russian Lunar Exploration. Springer Science & Business Media. p. 218. ISBN 978-0-387-73976-2.
- ^ "Zond 8, Landing Point" Archived 2011-09-27 at the Wayback Machine, NASA Solar System Exploration - Zond 8, Splashdown area.
- ^ ""COTS 1 (SpaceX Dragon 1), Splashdown area"". Archived from the original on December 10, 2010.
- ^ "History is made as Dragon splashes down safely in the Pacific! | Bad Astronomy | Discover Magazine". Blogs.discovermagazine.com. Archived from the original on July 5, 2012. Retrieved June 21, 2012.
- ^ "American Island". marinetraffic.com. Retrieved August 9, 2018.
- ^ "Dragon Returns to Earth". NASA. October 28, 2012. Retrieved October 29, 2012.
- ^ "SpaceX brings home Dragon with 2,700 pounds of cargo". Spaceflightnow. March 26, 2013. Retrieved March 27, 2013.
Bibliography
[edit]- Ezell, Linda Neumann (1988), NASA Historical Data Book (PDF), vol. II Programs and Projects 1958 - 1968 (NASA SP-4012), archived (PDF) from the original on October 9, 2022
- Ezell, Linda Neumann (1988), NASA Historical Data Book (PDF), vol. III - Programs and Projects 1969 - 1978 (SP-4012), archived (PDF) from the original on October 9, 2022
- Orloff, Richard W., Apollo By The Numbers - A Statistical Reference (NASA SP-2000-4029) (PDF), p. 143, archived (PDF) from the original on October 9, 2022
External links
[edit]- The dictionary definition of splashdown at Wiktionary