The Aquarius Habitat

Deployed 19 metres underwater, 5.6 km off Key Largo, in the Florida Keys National Marine Sanctuary, Aquarius is an undersea laboratory designed to support research in coastal and ocean resource science and management. The habitat itself, a steel cylinder 3 metres in diameter by 14 metres long, provides 11 cubic metres of living and laboratory space for a six-person crew. The lab is equipped with computers networked to shore, internet, telephones, radios and videoconferencing equipment.

Larger image of the Aquarius underwater habitat and laboratory

The Aquarius underwater habitat and laboratory (Credit: the National Oceanic and Atmospheric Administration's Undersea Research Center at the University of North Carolina Wilmington)

Aquarius is an ambient pressure habitat – this means its interior atmospheric pressure is equal to the surrounding water pressure. At this depth and pressure, visitors diving down to Aquarius have only about 80 minutes to complete their stay and return to the surface before they risk experiencing decompression-related illness.

However, the mission crew, known as "aquanauts," can stay indefinitely. They also have nearly unlimited time during their scuba dives, as long as they stay at the same depth. However, the cost of long stays at this pressure is that at the end of a mission, aquanauts must undergo a 17-hour decompression in a chamber within Aquarius itself in order to minimize the risk of decompression sickness. At the end of decompression, aquanauts exit the habitat and scuba dive back to the surface.

Aquarius missions usually last about ten days and are conducted from April through November. This extreme, hostile environment is analogous to conditions for human space flight and has been used by the National Aeronautics and Space Administration (NASA) in the training of Space Station astronauts and as a platform for research and technology development since 2001.

Aquarius provides NASA a convincing analog to space exploration. Much like space, the undersea world is a hostile, alien place for humans to live. NASA Extreme Environment Mission Operations (NEEMO) crew members experience some of the same tasks and challenges underwater as they would in space. For example, working in space and underwater environments requires extensive planning and sophisticated equipment. Working underwater also has a strong benefit to NASA because the aquanauts can be weighed out to simulate different gravity environments.

Aquarius is owned by the National Oceanic and Atmospheric Administration (NOAA) and managed by the University of North Carolina at Wilmington (UNCW) via the NOAA Undersea Research Center (NURC) in Key Largo, Florida. The laboratory is located in the Florida Keys National Marine Sanctuary and is on the ocean floor next to deep coral reefs 19 metres below the surface.

The Aquarius system has three elements: a life-support buoy at the surface, the habitat module and a base plate that secures the habitat to the ocean floor. The Aquarius habitat has about 37 square metres of living and laboratory space. This size is similar to that of the Zvezda Service Module of the International Space Station (ISS), which has served as the living quarters for Expedition crew members.

While underwater, NEEMO participants are able to simulate living on a spacecraft such as the ISS or to test extravehicular activities for future space missions. NASA sent its first set of NEEMO aquanauts to Aquarius in October 2001. The crew size varies from three to four, with UNCW engineers providing support.

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