Splashdown

Caribbean splashdown locations of American spacecraft

Splashdown was the method of landing by parachute in a body of water, utilized 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 from the large United States Navy which could more easily provide recovery ships and conduct operations than the relatively small Russian and Chinese navies.

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.

Pacific splashdown locations of American spacecraft

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 spacecraft had a flotation collar (similar to a rubber liferaft) attached to the it to increase 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.

Apollo hoisted onto ship. (NASA)

Apollo after splashdown. (NASA)

Apollo splashdown. (NASA)

The coordinates for the following spacecraft are estimated. No official numbers could be found, just 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.

• Sigma 7 - Landing site: 275 miles (440 km) North East of Midway Island.

• Faith 7 - Landing site: 115 miles (185 km) ESE (East South East) of Midway Island.