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Aquarius

Aquarius operates 5.6 km off the shores of Key Largo, Florida. The underwater laboratory is deployed next to deep coral reefs, 20 metres beneath the surface. Aquanauts, like astronauts in its outer-space counterpart, explore and investigate an environment hostile to human habitation. Aquarius provides life support systems that allow scientists to live and work underwater in comfortable living quarters. It has sophisticated research capabilities.

The Aquarius System

The fully equipped underwater laboratory includes several components. The Aquarius habitat module is an 82-ton, double-lock pressure vessel about 14 by 3 metres. Scientists live and work inside the habitat or they can set off for the reefs on diving excursions. Entry is through the 20-cubic-metre wet porch, which contains an open moon pool, dive equipment storage areas, and a hot-water heater and shower.

There are two main compartments in the Aquarius module. The 14-cubic metre entry lock has bench space for computers and experiments, power equipment, life support controls, small ports for viewing and washrooms. The largest living space is the 40-cubic-metre main lock, with berths for a six-person crew, computer work stations, two large view ports, dining and work areas, as well as kitchen facilities with a microwave, a hot water dispenser, refrigerator, and sink. The main lock also contains life support controls, because entry and main locks are independently pressurized.

The Aquarius baseplate is a 116-ton structure that provides a stable and level support base for the habitat. The four adjustable legs contain 25 tons of lead ballast and can level the station in relation to the variations found on the sea-floor terrain through the use of hydraulically driven screw jacks.

The life support buoy (LSB) is a 10-metre-wide buoy provided by NOAA's National Data Buoy Center.

It sits above Aquarius on a five-point mooring using thick, double-braided nylon lines connected to 1.5-metre-wide spring buoys. Mooring plates were installed with anchor bolts sunk 1.2 metres into the seafloor. The LSB includes a communication tower and over 70 square metres of inside workspace. Inside are two diesel-powered 40 kW generators, two 18.7-cubic-foot-per-minute air compressors, VHF radios, a cell phone, and microwave broadcasting system.

The LSB is linked to Aquarius by a three-inch-wide, 42-metre unitized umbilical with hoses that supply air from compressors and oxygen from storage flasks, as well as power lines from the generators, and two coaxial cables and pair wires for data and communications. The microwave telemetry system provides reliable wireless audio, video, and data transmission between Aquarius
and shore.

A shore-based mission control centre is located in Key Largo, about 12 kilometres from Aquarius, and includes a specially designed watch desk with computers and communication equipment with a wireless telemetry link to Aquarius. Also on shore are: docks for the program's boats; office space; storage and work rooms for dive gear and equipment; an electronics shop; a six-person, dual-lock decompression chamber for emergency evacuation of Aquarius; two laboratories; and living accommodations for on-duty staff and visiting scientists.

The advantages of saturation diving for scientists

Aquarius scientists avoid the limitations of conventional scuba diving through the use of saturation diving, where breathing under high pressure conditions causes the body tissues and blood to become saturated in inert gases. The most serious threat divers face when working underwater is decompression sickness, also known as "the bends." If a diver surfaces too quickly from a long, deep dive, bubbles that form in the blood and tissues get caught in joints and vessels, causing  pain, paralysis, and perhaps even death. This is because the bubbles come back out of solution in the tissues as the pressure decreases. In saturation diving, the decompression time is the same whether the dive is two hours or two days.

Instead of surfacing after diving, scientists who use Aquarius return to the undersea laboratory. They use special dive tables to calculate their bottom time, and can go nearly ten times longer than they would using surface-based diving. Without an underwater habitat, researchers are forced to make multiple dives of short duration, which leaves them vulnerable to the complications of daily boat trips, unpredictable weather, difficulties setting up sea-floor experiments that require power and computers from the surface, and frequent deep dives with the increased risk of suffering decompression sickness.

Aquarius science results

Aquarius supports scientists in their efforts to better understand oceans and coastal resources. An open and competitive peer-review process is used to select proposals submitted to the program on an annual basis; proposals target science and management issues of highest merit and relevance to NOAA, and in particular the Florida Keys National Marine Sanctuary. After nearly 50 missions, more than 200 scientists have participated directly in the program, representing over 90 organizations including universities from across the U.S. and several other countries.

Aquarius Undersea Laboratory Hosts Astronauts for Space Simulation and Training Project

During the seven-day mission the project team will live underwater using Aquarius as an analogue for working and training under environmental conditions  surprisingly similar to those in outer space.

Marine scientists who study coral reefs and our coastal ocean use Aquarius. The unique design of Aquarius allows aquanauts to live and work on the sea floor for extended periods using a special technique called saturation diving. Divers can spend more working in the ocean depths and they have onsite access to science equipment and computers—the lab even has an Internet connection.

Aquanauts stay underwater, isolated from the outside world for the duration of their mission because saturation diving requires lengthy decompression before surfacing. Isolation in an extreme environment is important for studies on behaviour and physiology. In particular, the NASA Aquarius experience will be used to help build crew–mission control communication techniques, and leadership and interpersonal skills.

Various NASA departments are involved in the mission. They monitor the progress of the astronaut crew from the Johnson Space Center in real-time. Underwater communications equipment and cameras will provide interactive capability between the aquanauts and NASA staff in Houston. A number of tasks performed inside Aquarius are designed to simulate similar functions to be performed in space. A goal of the mission is to use results of the mission to help NASA planners shape future training programs.

As with each Aquarius mission, the October 2001 effort will consist of two operations specialists from the University of North Carolina at Wilmington, Mark Hulsbeck and Ryan Snow, and four astronaut specialists. The four specialists include mission commander Bill Todd, a senior simulation supervisor with United Space Alliance; Shuttle astronaut and former commercial diver Mike Gernhardt; Shuttle astronaut Mike Lopez-Alegria; and Canadian astronaut Dave Williams.