underwater habitat
Underwater habitats are fixed underwater structures in which people can live for extended periods and carry out most of the basic human functions of a 24-hour day, such as working, resting, eating, attending to personal hygiene, and sleeping.
In this context 'habitat' is generally used in a narrow sense to mean the interior and immediate exterior of the structure and its fixtures, but not its surrounding marine environment.
An underwater habitat has to meet the needs of human physiology and provide suitable environmental conditions, and the one which is most critical is breathing air of suitable quality. Others concern the physical environment (pressure, temperature, light, humidity), the chemical environment (drinking water, food, waste products, toxins) and the biological environment (hazardous sea creatures, microrganisms, fungi).
Much of the science covering underwater habitats and their technology designed to meet human requirements is shared with diving, diving bells, submersible vehicles and submarines, and spacecraft.
There have been numerous underwater habitats designed, built and used around the world since the early 1960s, either by private individuals or by government agencies. In that time they have been used almost exclusively for research and exploration, but in recent years at least one underwater habitat has been provided for recreation and tourism. Research has been devoted particularly to the physiological processes and limits of breathing gases under pressure, for aquanaut and astronaut training, as well as for research on marine ecosystems.
Basic types of habitats
Underwater habitats are designed to operate in two fundamental modes.
- One: habitats open to ambient pressure via a moon pool, meaning that the air pressure inside the habitat equals underwater pressure at the same level, such as SEALAB, and which makes entry and exit easy as there is no physical barrier other than the moon pool water surface.
- Two: underwater habitats closed to the sea by hatches, with internal air pressure less than ambient pressure and at or closer to atmospheric pressure; entry or exit to the sea requires passing through hatches and an airlock.
A third type of habitat can be made by having compartments of both types within the same habitat structure and connected via airlocks, such as Aquarius (laboratory).
Conshelf I, II and III
Conshelf, short for Continental Shelf Station, was a series of undersea living and research stations undertaken by Jacques Cousteau's team in the 1960's. The original design was for five of these stations to be submerged to a maximum depth of 300m over the decade; in reality only three were completed with a maximum depth of 100m. Much of the work was funded in part by the French Petrochemical industry, who, along with Cousteau, hoped that such manned colonies could serve as base stations for the future exploitation of the sea. Such colonies did not find a productive future, however, as Cousteau later repudiated his support for such exploitation of the sea and put his efforts toward conservation. It was also found in later years that industrial tasks underwater could be more efficiently performed by undersea robot devices and men operating from the surface or from smaller lowered structures, made possible by a more advanced understanding of diving physiology. Still, these three undersea living experiments did much to advance man's knowledge of undersea technology and physiology, and were valuable as "proof of concept" constructs. They also did much to publicize oceanographic research and, ironically, usher in an age of ocean conservation through building public awareness. Along with Sealab and others, it spawned a generation of smaller, less ambitious yet longer-term undersea habitats primarily for marine research purposes. (See below)
Conshelf I (Continental Shelf Station), constructed in 1962 was the first inhabited underwater
habitat. Developed by Jacques-Yves Cousteau to record basic observations of life
underwater, Conshelf I was submerged in 10 metres of water near Marseilles, and the first
experiment involved a team of two spending seven days in the habitat. The two oceanauts, Albert Falco and Claude Wesly, were
expected to spend at least five hours a day outside of the station, and were subject to daily medical exams. They were among the
first to breath a mixture of helium and oxygen, avoiding the
normal nitrogen/oxygen mixture which when breathed under pressure can cause temporary mental
instability. This was also an early effort in saturation diving, in which the
oceanauts' body tissues were allowed to become totally saturated by the helium in the breathing mixture, a result of breathing
the gases under pressure. Normally, this would prove fatal when the team returned to the surface, at which time reduced pressure
would cause the helium to bubble out into the divers joints and tissues, afflicting them with the bends. The conventional solution would have been to subject the divers to lengthy and complex
decompression; however, in this case the divers' instead breathed an oxygen-rich mixture of gases for a few hours before
returning to the surface in order to purge the excess helium from their tissues. They suffered no apparent ill affects.
Conshelf Two, the first ambitious attempt for men to live and work on the
sea floor, was launched in 1963. In it, a half-dozen oceanauts lived 10 meters down in the Red
Sea off Sudan in a starfish-shaped house for 30 days. The
undersea living experiment also had two other structures, one a submarine hangar that housed a small, two man submarine referred to as the "diving saucer" for its resemblance to a science fiction flying saucer, and a
smaller "deep cabin" where two oceanauts lived at a depth of 30 meters for a week. The undersea colony was supported with air,
water, food, power, all essentials of life, from a large support team above. Men on the bottom performed a number of experiments
intended to determine the practicality of working on the sea floor and were subjected to continual medical examinations. Conshelf
II was a defining effort in the study of diving physiology and technology, and captured wide public appeal due to its dramatic
"Jules Verne" look and feel. A Cousteau-produced feature film about the effort was awarded
an Academy Award for Best Documentary the following year.
Conshelf III was tested in 1965, six divers lived in the habitat at 100 metres in the
Mediterranean near the Île du Levant for three
weeks. In this effort, Cousteau was determined to make the station more self-sufficient, severing most ties with the surface. A
mock oil rig was set up underwater, and divers successfully performed several industrial
tasks.
SEALAB I, II and III
- See main article SEALAB
SEALAB was developed by the United States Navy, primarily to research the physiological aspects of saturation diving.
Tektite I and II
The Tektite underwater habitat was constructed by General Electric and was funded by NASA, the Office of Naval Research and the Department of Interior.
On February 15, 1969, four U. S. Department of Interior scientists descended to the ocean floor in Great Lameshur Bay in the U. S. Virgin Islands and occupied the Tektite I. By March 18, 1969, the four aquanauts had established a new world's record for saturated diving by a single team. On April 15, 1969, the aquanaut team returned to the surface with over 58 days of marine scientific studies.
The Tektite II missions were carried out in 1970. Tektite II comprised ten missions lasting 10-20 days with four scientists and an engineer on each mission. The Tektite II missions were the first to undertake in-depth ecological studies.
The Tektite Project was led by Dr. Theodore Marton who worked for General Electric
Hydrolab
Hydrolab was constructed in 1966 and used as a research station from 1970, the project was in part funded by the National Oceanic and Atmospheric Administration (NOAA). Hydrolab could house 4 people. Approximately 180 Hydrolab missions were conducted; 100 missions in the Bahamas during the early to mid 1970s, and 80 missions in St. Croix, United States Virgin Islands, from 1977 to 1985 .
The habitat was decommissioned in 1985 and placed on display at the Smithsonian Institution’s National History Museum in Washington, D.C.. The habitat is now located at the headquarters of the National Oceanic and Atmospheric Administration (NOAA) in Silver Spring, MD.
Aquarius
- See main article Aquarius.
Aquarius is presently one of the world's only operational underwater laboratories. It is located adjacent to a coral reef in the Florida Keys National Marine Sanctuary.
MarineLab
The MarineLab [1] underwater laboratory is the longest serving seafloor habitat in history, having operated continuously in an unbroken service since 1984 under the direction of aquanaut Chris Olstad [2] at Key Largo, Florida. The seafloor laboratory has trained hundreds of individuals in that time featuring an extensive array of educational and scientific investigations from US Military investigations to pharmaceutical development.
Beginning with a project initiated in 1973, MarineLab, then known as MEDUSA (Midshipman Engineered & Designed Undersea Systems Apparatus), was designed and built as part of an ocean engineering student program at the United States Naval Academy under the direction of Dr. Neil T. Monney. In 1983, MEDUSA was donated to the Marine Resources Development Foundation (MRDF), and in 1984 was deployed on the seafloor in John Pennekamp Coral Reef State Park, Key Largo, Florida. The 8 X 16 - foot (2.5 X 4.9m) shore-supported habitat supports 3-4 persons and is divided into a laboratory, a wet-room, and a 5’ 6” (1.7m) transparent observation sphere. From the beginning, it has been used by students for observation, research, and instruction. In 1985, it was renamed MarineLab and moved to the 30-foot (9.2m) deep mangrove lagoon at MRDF headquarters in Key Largo at a depth of 27 foot (8.3m) with a hatch depth of 20 feet (6.2m). The lagoon contains artifacts and wrecks placed there for education and training. During 1993-95, NASA used MarineLab repeatedly to study Controlled Ecological Life Support Systems (CELLS). These education and research programs qualify MARINE-LAB as the world’s most extensively used habitat.
La Chalupa Research Laboratory
In the early 70's, Ian Koblick, president of Marine Resources Development Foundation, developed and operated the La Chalupa research laboratory, which was the largest and most technologically advanced underwater habitat of its time. Koblick, who has continued his work as a pioneer in developing advanced undersea programs for ocean science and education, is the co-author of the book "Living and Working in the Sea" and is considered one of the foremost authorities on undersea habitation.
In the mid 80's La Chalupa was transformed into Jules' Undersea Lodge. Jules' co-developer Dr. Neil Monney formerly served as Professor and Director of Ocean Engineering at the U.S. Naval Academy, and has extensive experience as a research scientist, aquanaut, and designer of underwater habitats. Jules' has had over 10,000 overnight guests in its 20 years of operation. It is still the only underwater hotel in the world. [3]
In popular culture
- Sealab 2020, an animated series from the 1970s, takes place in a fictional underwater research lab, as does Cartoon Network's reworking of the show, Sealab 2021.
- The Abyss, a 1989 movie that takes place in an underwater habitat.
- In The Spy Who Loved Me, the film's villain, Karl Stromberg, lives in an underwater fortress.
- SeaQuest DSV featured numerous underwater colonies, research facilities, and military installations.
References
- Gregory Stone: "Deep Science". National Geographic Online Extra (Sept 2003). Retrieved 29 July 2007.
- BBC. Living under the sea
- Colette, B.B. Results of the Tektite program: Ecology of coral-reef fishes
- Middleton, N. Conshelf - Cousteau’s Cutting Edge
- Miller, J.W. 1970. Tektite: Expectations and costs. Science 169: 1264-1265.
- Miller, J.W., Koblick, I. 1997. Living and Working in the Sea
External links
- Jules' Undersea Lodge
- Trilobis 65 Floating Home
- US Naval Undersea Museum SEALAB II Display
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