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Splashdown

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Apollo 15 makes contact with the Pacific Ocean.
Locations of Atlantic Ocean splashdowns of American spacecraft prior to the 21st century
Locations of Pacific Ocean 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.[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]
Apollo 14 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.[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]

The splashdown of the SpaceX CRS-25 resupply mission

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

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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

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Space Shuttle SRB being recovered by Freedom Star 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.[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

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Crewed spacecraft

[edit]
# Spacecraft Agency Landing date Coordinates Recovery ship Miss distance (km) Reference
1 Freedom 7 NASA May 5, 1961 27°13.7′N 75°53′W / 27.2283°N 75.883°W / 27.2283; -75.883 (Freedom 7) USS Lake Champlain 5.6 km (3.5 mi) [19]
2 Liberty Bell 7 NASA July 21, 1961 27°32′N 75°44′W / 27.533°N 75.733°W / 27.533; -75.733 (Liberty Bell 7) USS Randolph 9.3 km (5.8 mi) [20]
3 Friendship 7 NASA February 20, 1962 21°26′N 68°41′W / 21.433°N 68.683°W / 21.433; -68.683 (Friendship 7) USS Noa
(USS Randolph**)
74 [21]
4 Aurora 7 NASA May 24, 1962 19°27′N 63°59′W / 19.450°N 63.983°W / 19.450; -63.983 (Aurora 7) USS John R. Pierce
(USS Intrepid**)
400 [22]
5 Sigma 7 NASA October 3, 1962 32°06′N 174°28′W / 32.100°N 174.467°W / 32.100; -174.467 (Sigma 7) USS Kearsarge 7.4 [23]
6 Faith 7 NASA May 16, 1963 27°20′N 176°26′W / 27.333°N 176.433°W / 27.333; -176.433 (Faith 7) USS Kearsarge 8.1 [24]
7 Gemini 3 NASA March 23, 1965 22°26′N 70°51′W / 22.433°N 70.850°W / 22.433; -70.850 (Gemini 3) USS Intrepid 111 [25]
8 Gemini 4 NASA June 7, 1965 27°44′N 74°11′W / 27.733°N 74.183°W / 27.733; -74.183 (Gemini 4) USS Wasp 81 [26]
9 Gemini 5 NASA August 29, 1965 29°44′N 69°45′W / 29.733°N 69.750°W / 29.733; -69.750 (Gemini 5) USS Lake Champlain 270 [27]
10 Gemini 7 NASA December 18, 1965 25°25′N 70°07′W / 25.417°N 70.117°W / 25.417; -70.117 (Gemini 7) USS Wasp 12 [28]
11 Gemini 6A NASA December 16, 1965 23°35′N 67°50′W / 23.583°N 67.833°W / 23.583; -67.833 (Gemini 6A) USS Wasp 13 [29]
12 Gemini 8 NASA March 17, 1966 25°14′N 136°0′E / 25.233°N 136.000°E / 25.233; 136.000 (Gemini 8) USS Leonard F. Mason
(USS Boxer**)
2 [30]
13 Gemini 9A NASA June 6, 1966 27°52′N 75°0′W / 27.867°N 75.000°W / 27.867; -75.000 (Gemini 9A) USS Wasp 0.7 [31]
14 Gemini 10 NASA July 21, 1966 26°45′N 71°57′W / 26.750°N 71.950°W / 26.750; -71.950 (Gemini 10) USS Guadalcanal 6 [32]
15 Gemini 11 NASA September 15, 1966 24°15′N 70°0′W / 24.250°N 70.000°W / 24.250; -70.000 (Gemini 11) USS Guam 5 [33]
16 Gemini 12 NASA November 15, 1966 24°35′N 69°57′W / 24.583°N 69.950°W / 24.583; -69.950 (Gemini 12) USS Wasp 5 [34]
17 Apollo 7 NASA October 22, 1968 27°32′N 64°04′W / 27.533°N 64.067°W / 27.533; -64.067 (Apollo 7) USS Essex 3 [35]
18 Apollo 8 NASA December 27, 1968 8°7.5′N 165°1.2′W / 8.1250°N 165.0200°W / 8.1250; -165.0200 (Apollo 8) USS Yorktown 2 [36]
19 Apollo 9 NASA March 13, 1969 23°15′N 67°56′W / 23.250°N 67.933°W / 23.250; -67.933 (Apollo 9) USS Guadalcanal 5 [37][38]
20 Apollo 10 NASA May 26, 1969 15°2′S 164°39′W / 15.033°S 164.650°W / -15.033; -164.650 (Apollo 10) USS Princeton 2.4 [39][40]
21 Apollo 11 NASA July 24, 1969 13°19′N 169°9′W / 13.317°N 169.150°W / 13.317; -169.150 (Apollo 11) USS Hornet 3.13 [41][42]
22 Apollo 12 NASA November 24, 1969 15°47′S 165°9′W / 15.783°S 165.150°W / -15.783; -165.150 (Apollo 12) USS Hornet 3.7 [43][44]
23 Apollo 13 NASA April 17, 1970 21°38′S 165°22′W / 21.633°S 165.367°W / -21.633; -165.367 (Apollo 13) USS Iwo Jima 1.85 [45][46]
24 Apollo 14 NASA February 9, 1971 27°1′S 172°39′W / 27.017°S 172.650°W / -27.017; -172.650 (Apollo 14) USS New Orleans 1.1 [47][48]
25 Apollo 15 NASA August 7, 1971 26°7′N 158°8′W / 26.117°N 158.133°W / 26.117; -158.133 (Apollo 15) USS Okinawa 1.85 [49][50]
26 Apollo 16 NASA April 27, 1972 0°43′S 156°13′W / 0.717°S 156.217°W / -0.717; -156.217 (Apollo 16) USS Ticonderoga 0.55 [51][52]
27 Apollo 17 NASA December 19, 1972 17°53′S 166°7′W / 17.883°S 166.117°W / -17.883; -166.117 (Apollo 17) USS Ticonderoga 1.85 [53][54]
28 Skylab 2 NASA June 22, 1973 24°45′N 127°2′W / 24.750°N 127.033°W / 24.750; -127.033 (Skylab 2) USS Ticonderoga [55]
29 Skylab 3 NASA September 25, 1973 30°47′N 120°29′W / 30.783°N 120.483°W / 30.783; -120.483 (Skylab 3) USS New Orleans [56]
30 Skylab 4 NASA February 8, 1974 31°18′N 119°48′W / 31.300°N 119.800°W / 31.300; -119.800 (Skylab 4) USS New Orleans [56]
31 Apollo CSM-111 NASA July 24, 1975 22°N 163°W / 22°N 163°W / 22; -163 (ASTP Apollo) USS New Orleans 1.3 [57][58]
32 Soyuz 23 USSR October 16, 1976 Lake Tengiz Mi-8 helicopter [59]
33 Crew Dragon Demo-2 SpaceX August 2, 2020 29°48′N 87°30′W / 29.800°N 87.500°W / 29.800; -87.500 (Crew Dragon Demo-2) GO Navigator [60]
33 Crew Dragon Crew-1 SpaceX May 2, 2021 29°32′N 86°11′W / 29.533°N 86.183°W / 29.533; -86.183 (Crew Dragon Crew-1) GO Navigator [61]
34 Inspiration4 SpaceX September 18, 2021 GO Searcher [62]
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 [63]
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

Uncrewed spacecraft

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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 / 16.5650; -49.77117 (Gemini 2) 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 / -8.18; -11.15 (Apollo 201) 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 / 16.12; 168.9 (Apollo 202) 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 / 30.1; -172.53 (Apollo 4) 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 / 27.667; -157.983 (Apollo 6) USS Okinawa ? km[74]
Zond 5 USSR September 21, 1968 32°38′S 65°33′E / 32.63°S 65.55°E / -32.63; 65.55 (Zond 5) 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 / -17; 98 (Cosmos 1374) 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 / 26.92; -120.7 (Dragon C2+) ? ?[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 / 23.6; -116.4 (EFT-1), 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
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See also

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Notes

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  1. ^ 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]
  1. ^ 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.
  2. ^ "Launch Services Program Launch Sites". NASA. May 14, 2009. Retrieved August 7, 2020.
  3. ^ Archived at Ghostarchive and the Wayback Machine: "The Accidental Spacecraft Splashdown Which Almost Killed Its Crew" – via www.youtube.com.
  4. ^ "Soyuz-23, Lands On A Frozen Lake". VideoCosmos. Archived from the original on April 14, 2012. Retrieved June 21, 2012.
  5. ^ Bob Fish. "Apollo 11 & 12 Recovery". USS Hornet Museum's website.
  6. ^ McRea, Aaron. "Dragon receives long-planned propulsive landing upgrade after years of development". Nasa Spaceflight. Retrieved November 11, 2024.
  7. ^ Clark, Stephen (January 12, 2021). "Cargo Dragon heads for splashdown off Florida's west coast". Spaceflight Now. Retrieved January 14, 2021.
  8. ^ "AUDIT OF COMMERCIAL RESUPPLY SERVICES TO THE INTERNATIONAL SPACE STATION" (PDF). Archived (PDF) from the original on October 9, 2022.
  9. ^ "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.
  10. ^ 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.
  11. ^ 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.
  12. ^ Verhagen, J.H.G (1967). "The Impact of a Flat Plate on a Water Surface". Journal of Ship Research.
  13. ^ 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.
  14. ^ "Carbon Dioxide (CO2) OCHMO-TB-004 Rev C" (PDF). NASA. Retrieved November 27, 2024.
  15. ^ "A FRAMEWORK FOR ASSESSING THE REUSABILITY OF HARDWARE (REUSABLE ROCKET ENGINES" (PDF). NASA. p. 4-5. Retrieved November 11, 2024.
  16. ^ Gebhardt, Chris (July 8, 2012). "One year on – Review notes superb performance of STS-135's SRBs". NASA Spaceflight. Retrieved November 27, 2024.
  17. ^ Bergin, Chris (January 13, 2019). "CRS-16 Dragon returns to Earth following ISS departure". NASA Spaceflight. Retrieved November 27, 2024.
  18. ^ Coldewey, Devin (November 19, 2020). "Rocket Lab makes its first booster recovery after successful launch". TechCrunch. Retrieved November 27, 2024.
  19. ^ Ezell (1988) p. 143
  20. ^ Ezell (1988) p. 144
  21. ^ Ezell, Volume II, p. 145
  22. ^ Ezell, Volume II, p. 146
  23. ^ Ezell, Volume II, p. 147
  24. ^ Ezell, Volume II, p. 148
  25. ^ Ezell, Volume II, p. 159
  26. ^ Ezell, Volume II, p. 160
  27. ^ Ezell, Volume II, p. 161
  28. ^ Ezell, Volume II, p. 162
  29. ^ Ezell, Volume II, p. 163
  30. ^ Ezell, Volume II, p. 164
  31. ^ Ezell, Volume II, p. 165
  32. ^ Ezell, Volume II, p. 166
  33. ^ Ezell, Volume II, p. 167
  34. ^ Ezell, Volume II, p. 168
  35. ^ Ezell, Volume II, p. 188
  36. ^ Ezell, Volume II, p. 189
  37. ^ Ezell, Volume III, p. 83
  38. ^ Orloff, p. 58
  39. ^ Ezell, Volume III, p. 84
  40. ^ Orloff, p. 78
  41. ^ Ezell, Volume III, p. 85
  42. ^ Orloff, p. 98
  43. ^ Ezell, Volume III, p. 86
  44. ^ Orloff, p. 120
  45. ^ Ezell, Volume III, p. 87
  46. ^ Orloff, p. 143
  47. ^ Ezell, Volume III, p. 88
  48. ^ Orloff, p. 168
  49. ^ Ezell, Volume III, p. 89
  50. ^ Orloff, p. 197
  51. ^ Ezell, Volume III, p. 91
  52. ^ Orloff, p. 225
  53. ^ Ezell, Volume III, p. 92
  54. ^ Orloff, p. 251
  55. ^ Ezell, Volume III, p. 104
  56. ^ a b Ezell, Volume III, p. 105
  57. ^ Ezell, Volume III, p. 112
  58. ^ "ASTP Apollo Miss Distance", ASTP Summary Science Report - Mission Description p. 36, Archived 2010-02-14 at the Wayback Machine
  59. ^ "Cosmonauts Land in Lake, Blizzard". The Milwaukee Journal. UPI. October 18, 1976.
  60. ^ "NASA Astronauts in SpaceX Capsule Make First Water Landing Since 1975". The New York Times. August 2, 2020.
  61. ^ "SpaceX Dragon splashes down in Gulf of Mexico, bringing 4 astronauts home". Orlando Sentinel. May 2, 2021.
  62. ^ "SpaceX capsule returns four civilians from orbit, capping off first tourism mission". CNN.com. September 18, 2021.
  63. ^ Jackie Wattles. "SpaceX's wildly busy year continues with astronaut splashdown". CNN. Retrieved May 6, 2022.
  64. ^ "Animals Survive 1,500-Mile Ride In Rocket Nose". The Windsor Daily Star. Windsor, Ontario. Associated Press. May 28, 1959.
  65. ^ "Big Joe Shot". nasa.gov. Retrieved August 9, 2018.
  66. ^ "Monkey Completes Long Flight Aloft". Ellensburg Daily Record. Ellensburg, Washington. December 4, 1959.
  67. ^ "Man-In-Space Capsule To Be Closely Studied". The Florence Times. Florence, Alabama. Associated Press. December 20, 1960.
  68. ^ a b "USS Donner LSD20". Homestead.com. Retrieved June 21, 2012.
  69. ^ "Chimp Survives Space Shot". The Milwaukee Sentinel. Associated Press. February 1, 1961.
  70. ^ "Space Capsule Soars 107 Miles High". The Florence Times. Florence, Alabama. Associated Press. February 21, 1961.
  71. ^ "U.S. Robot Orbited, Returned". Meriden Journal. September 13, 1961.
  72. ^ "Capsule Trouble Forces Early Landing Of Craft". Toledo Blade. Toledo, Ohio. Associated Press. November 29, 1961.
  73. ^ "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)
  74. ^ a b c d Mansfield, Cheryl L. (January 9, 2018). "Apollo-Saturn Unmanned Missions". NASA.
  75. ^ "Titan 3 Gives Spectacular Space Show". Sarasota Journal. Sarasota, Florida. November 3, 1966.
  76. ^ Michael Cassutt (2007). Red Moon. Tom Doherty Associates. p. 320. ISBN 978-1-4299-7172-0.
  77. ^ "Zond 5, Landing Point, Miss Distance" Archived 2011-09-27 at the Wayback Machine, NASA Solar System Exploration - Zond 5, Landing Point, Miss Distance.
  78. ^ Brian Harvey (2007). Soviet and Russian Lunar Exploration. Springer Science & Business Media. p. 218. ISBN 978-0-387-73976-2.
  79. ^ "Zond 8, Landing Point" Archived 2011-09-27 at the Wayback Machine, NASA Solar System Exploration - Zond 8, Splashdown area.
  80. ^ ""COTS 1 (SpaceX Dragon 1), Splashdown area"". Archived from the original on December 10, 2010.
  81. ^ "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.
  82. ^ "American Island". marinetraffic.com. Retrieved August 9, 2018.
  83. ^ "Dragon Returns to Earth". NASA. October 28, 2012. Retrieved October 29, 2012.
  84. ^ "SpaceX brings home Dragon with 2,700 pounds of cargo". Spaceflightnow. March 26, 2013. Retrieved March 27, 2013.

Bibliography

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[edit]
  • The dictionary definition of splashdown at Wiktionary