Splashdown
|
|
Splashdown.png
Splashdown was the method of landing by parachute in a body of water, used by American manned spacecraft prior to the Space Shuttle. As the name suggests, the capsule parachutes into an ocean or other large body of water. The properties of the 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 instead. 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. There were a few cases in which Russian manned spacecraft landed in inland waters, but these were unintentional.
While the water the spacecraft landed on would cushion it to some degree, the impact could still be quite violent for the astronauts. On Apollo 12, a camera mounted by one of the command module's windows broke loose and hit Alan Bean on the head, rendering him unconscious.
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 4 capsule malfunctioned and blew prematurely. The capsule was lost and Grissom nearly drowned.
Splashdown_2.png
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 retro attitude misalignment of the spacecraft automatic guidance system and a late manual retrofire. It took three hours before a recovery helicopter reached his location. This can be mitigated by having several vessels on standby for recovery in several different locations, but this is obviously quite an expensive option.
On early Mercury flights, a helicopter attached a cable to the capsule, lifted it from the water and delivered it to a nearby ship. After the sinking of Liberty Bell 7, this was changed. All later Mercury, Gemini and Apollo capsules had a flotation collar (similar to a rubber liferaft) attached to the spacecraft to increase their buoyancy. The spacecraft would then be brought along side 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.
Space capsules are not very good boats and many astronauts got seasick.
Future American space capsules will probably use a parasail type parachute to make softer landings on dry land.
Splashdown_2.jpg
Splashdown_3.jpg
Splashdown_4.jpg
The coordinates for the following spacecraft are estimated. No official numbers could be found, just small recovery zone diagrams or distance descriptions to nearby islands:
- Friendship 7 - Landing site: 200 nm (370 km) WNW of San Juan, Puerto Rico and 166 miles (267 km) East of Grand Turk Island. According to a chart printed in the NASA publication, "Results of the First United States Manned Orbital Space Flight, Feb. 20, 1962", the landing coordinates are near Template:Coor dm.
- Sigma 7 - Landing site: 275 miles (440 km) North East of Midway Island. 275 miles (440 km) NE of Midway Island. The landing coordinates were near 32° 7' 30" N - 174° 45' W according to a chart in NASA publication SP-12 "Results of the Third U.S. Manned Orbital Space Flight, October 3, 1962" .
- Faith 7 - Landing site: According to NASA SP-45 "Mercury Project Summary Including Results of the Fourth Manned Orbital Flight", Faith 7 landed 70 nautical miles (130-km) South East of Midway Island. This would be near Template:Coor dm.
Manned Spacecraft Splashdown Data
Planned recovery ship **
Unmanned Spacecraft Splashdown Data
| Spacecraft | Landing Date | Coordinates | Recovery Ship | Miss Distance |
|---|---|---|---|---|
| Jupiter AM-18 | May 28, 1959 | 2,735 km SE Cape Canaveral | USS Kiowa ATF-72 (http://www.history.navy.mil/danfs/k4/kiowa-iii.htm) | ? km |
| Mercury-Big Joe | September 9, 1959 | 2,407 km SE Cape Canaveral | USS Strong DD-758 (http://www.destroyersonline.com/usndd/dd758/) | 925 km |
| Mercury-Little Joe 2 | December 4, 1959 | 319 km SE Wallops Is, VA | USS Borie DD-704 (http://www.destroyersonline.com/usndd/dd704/) | ? 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 (http://www.homestead.com/USSDONNERLSD20/index.html) | 111 km |
| Mercury-Atlas 2 | February 21, 1961 | 2,305 km SE Cape Canaveral | USS Donner LSD-20 (http://www.homestead.com/USSDONNERLSD20/index.html) | 30? km |
| Mercury-Atlas 4 | September 13, 1961 | 320 km E of Bermuda | USS Decatur DD 936 (http://www.history.navy.mil/photos/sh-usn/usnsh-d/dd936.htm) | 63 km |
| Mercury-Atlas 5 | November 29, 1961 | 472 km SE of Bermuda | USS Stormes DD-780 (http://www.destroyersonline.com/usndd/dd780/) | 48 km |
| Gemini 2 | January 19, 1965 | Template:Coor dm | USS Lake Champlain CVS 39 | 38 km |
| Apollo 201 | February 26, 1966 | 8.18° S - 11.15° W | USS Boxer LPH 4 | 72 km |
| Apollo 202 | August 25, 1966 | 16.12° N - 168.9° 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 | 30.1° N - 172.53° W | USS Bennington CVS-20 | 16 km |
| Apollo 6 | April 4, 1968 | Template:Coor dm | USS Okinawa LPH-3 | 80 km |