Splashdown (spacecraft landing)

Int




Atlantic Ocean splashdowns of American spacecraft.
Credit: NASA.

Pacific Ocean splashdowns of American spacecraft.
Credit: NASA.

Splashdown is the method of landing a spacecraft by parachute in a body of water. It was used by American manned spacecraft prior to the Space Shuttle program. It is also possible for the Russian Soyuz spacecraft and Chinese Shenzhou spacecraft to land in water, though this is only a contingency. The only example of the splashdown in Soviet history is Soyuz 23 landing.

As the name suggests, the capsule parachutes into an ocean or other large body of water. The properties of water cushion the spacecraft enough that there is no need for a braking rocket to slow the final descent as was the case with Russian and Chinese manned space capsules, which returned to Earth over land. The American practice came in part because American launch sites are on the coastline and launch primarily over water. Russian and Chinese launch sites are far inland and most early launch aborts are likely to descend on land.

The splashdown method of landing was utilized for Mercury, Gemini and Apollo (including Skylab, which used Apollo capsules). On one occasion a Soviet spacecraft, Soyuz 23, punched through the ice of a frozen lake (nearly killing the cosmonauts), but this was unintentional.

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. (Because of his overshoot aboard Aurora 7, and mindful of the fate of Liberty Bell 7, Scott Carpenter alone egressed through the nose of his capsule instead of through the hatch, waiting for recovery forces in his life raft.) 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.

The new Crew Exploration Vehicle, which will replace the Space Shuttle (which lands on a modified aircraft-style runway), will be designed to be recovered on land using a combination of parachutes and airbags, although it is also designed to make a contingency splashdown (only for an in-flight abort) if needed. Although not new, NASA and the Air Force originally wanted to place a paraglider recovery system to allow for a controlled, precise landing on land on ski-like skids (a landing system used on X-15 rocket plane), most likely on the dry lakebeds at Edwards Air Force Base in California. This idea was first proposed for the Gemini spacecraft, but was dropped in favor of the traditional parachute system.

Disadvantages:

While the water the spacecraft landed on would cushion it to some degree, the impact could still be quite violent for the astronauts.

There are several disadvantages for splashdowns, foremost among them being the danger of the spacecraft flooding and sinking. This happened to Gus Grissom when the hatch of his Mercury-Redstone 4 capsule malfunctioned and blew prematurely. The capsule was lost and Grissom nearly drowned. Space capsules are also not very good boats and many astronauts got seasick.

Another problem associated with splashdown is that if the capsule comes down far from any recovery forces the crew are exposed to greater danger. As an example, Scott Carpenter in Mercury 7 overshot the assigned landing zone by 400 km. This was caused by a retroattitude misalignment caused by the spacecraft automatic guidance system. It took three hours for a recovery helicopter to reach his location. These recovery operation mishaps can be mitigated by placing several vessels on standby in several different locations, but this is quite an expensive option.

Locations of splashdowns:

Manned spacecraft:

Spacecraft Landing Date Coordinates Recovery Ship Miss Distance
 Freedom 7  May 5, 1961  2713.7'N 7553'W  USS Lake Champlain CVS 39  5.6 km
 Liberty Bell 7  July 21, 1961  2732'N 7544'W  USS Randolph CVS-15  9.3 km
 Friendship 7  February 20, 1962  2126'N 6841'W  USS Noa DD-841
(USS Randolph CVS-15**)
 74 km
 Aurora 7  May 24, 1962  1927'N 6359'W  USS Farragut DLG-6
(USS Intrepid CVS-11**)
 400 km
 Sigma 7  October 3, 1962  3206'N 17428'W  USS Kearsarge CVS-33  7.4 km
 Faith 7  May 16, 1963  2720'N 17626'W  USS Kearsarge CVS-33  8.1 km
 Gemini 3  March 23, 1965  2226'N 7051'W  USS Intrepid CVS-11  111 km
 Gemini 4  June 7, 1965  2744'N 7411'W  USS Wasp CVS-18  81 km
 Gemini 5  August 29, 1965  2944'N 6945'W  USS Lake Champlain CVS 39  270 km
 Gemini 7  December 18, 1965  2525'N 7007'W  USS Wasp CVS-18  12 km
 Gemini 6A  December 16, 1965  2335'N 6750'W  USS Wasp CVS-18  13 km
 Gemini 8  March 17, 1966  2514'N 1360'E  USS Mason DD-852
(USS Boxer LPH 4**)
 2 km
 Gemini 9A  June 6, 1966  2752'N 750'W  USS Wasp CVS-18  0.7 km
 Gemini 10  July 21, 1966  2645'N 7157'W  USS Guadalcanal LPH-7  6 km
 Gemini 11  September 15, 1966  2415'N 700'W  USS Guam LPH-9  5 km
 Gemini 12  November 15, 1966  2435'N 6957'W  USS Wasp CVS-18  5 km
 Apollo 1  March 7, 1967  Planned N of Puerto Rico  USS Essex CVS-9**  Planned
 Apollo 7  October 22, 1968  2732'N 6404'W  USS Essex CVS-9  3 km
 Apollo 8  December 27, 1968  87.5'N 1651.2'W  USS Yorktown CVS-10  2 km
 Apollo 9  March 13, 1969  2315'N 6756'W  USS Guadalcanal LPH-7  5 km
 Apollo 10  May 26, 1969  152'S 16439'W  USS Princeton CVS-37  2.4 km
 Apollo 11  July 24, 1969  1319'N 1699'W  USS Hornet CVS-12  3.1 km
 Apollo 12  November 24, 1969  1547'S 1659'W  USS Hornet CVS-12  3.7 km
 Apollo 13  April 17, 1970  2138'24'S 16521'42'W  USS Iwo Jima LPH-2  1.9 km
 Apollo 14  February 9, 1971  271'S 17239'W  USS New Orleans LPH-11  1.1 km
 Apollo 15  August 7, 1971  267'N 1588'W  USS Okinawa LPH-3  1.9 km
 Apollo 16  April 27, 1972  045'S 15613'W  USS Ticonderoga CVS-14  5.6 km
 Apollo 17  December 19, 1972  1753'S 1667'W  USS Ticonderoga CVS-14  1.9 km
 Skylab 2  June 22, 1973  2445'N 1272'W  USS Ticonderoga CVS-14  9.6 km
 Skylab 3  September 25, 1973  3047'N 12029'W  USS New Orleans LPH-11  8 km?
 Skylab 4  February 8, 1974  3118'N 11948'W  USS New Orleans LPH-11  8 km?
 ASTP Apollo  July 24, 1975  2152'N 16245'W  USS New Orleans LPH-11  7.3 km
 Soyuz 23  October 16, 1976  Lake Tengiz  Helicopter Mi-8  Not intended to land in water


Planned recovery ship **

Unmanned spacecraft:

Spacecraft Landing Date Coordinates Recovery Ship Miss Distance
 Jupiter AM-18  May 28, 1959  2,735 km SE Cape Canaveral  USS Kiowa ATF-72   ? km
  Mercury-Big Joe  September 9, 1959  2,407 km SE Cape Canaveral  USS Strong DD-758  925 km
 Mercury-Little Joe 2  December 4, 1959  319 km SE Wallops Is, VA  USS Borie DD-704   ? km
 Mercury-Redstone 1A  December 19, 1960  378.2 km SE Cape Canaveral  USS Valley Forge CV-45  33 km
 Mercury-Redstone 2  January 31, 1961  679 km SE Cape Canaveral  USS Donner LSD-20  111 km
 Mercury-Atlas 2  February 21, 1961  2,305 km SE Cape Canaveral  USS Donner LSD-20  30? km
 Mercury-Atlas 4  September 13, 1961  320 km E of Bermuda  USS Decatur DD 936  63 km
 Mercury-Atlas 5  November 29, 1961  472 km SE of Bermuda  USS Stormes DD-780  48 km
 Gemini 2  January 19, 1965  1633.9'N 4946.27'W  USS Lake Champlain CVS 39  38 km
 Apollo 201  February 26, 1966  811'S 1109'W  USS Boxer LPH 4  72 km
 Apollo 202  August 25, 1966  1607'N 16854'E  USS Hornet CVS-12  370 km
 Gemini 2-MOL  November 3, 1966  SE KSC near Ascension Is.  USS La Salle LPD-3  13 km
 Apollo 4  November 9, 1967  3006'N 17232'W  USS Bennington CVS-20  16 km
 Apollo 6  April 4, 1968  2740'N 15759'W  USS Okinawa LPH-3  80 km
 Zond 5  September 21, 1968  3238'S 6533'E  Vasiliy Golovin
 Zond 8  October 27, 1970  Indian Ocean



References


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