ImageMissions in Aquarius typically last ten days and aquanaut trainees undergo five days of specialized training before each mission starts. Missions are conducted on a monthly basis from April through November. From 1993 to 1996, Aquarius was operated from a large (100 feet long by 50 feet wide) manned barge, known as the MSB (Mobile Support Base), which was located immediately above the underwater laboratory. Offshore operations were supported during missions by staff working on 12 hour rotating shifts. As part of the refurbishment in 1997, the barge was replaced by a semi–autonomous (unmanned) Life Support Buoy (LSB) provided by NOAA’s National Data Buoy Center. The LSB is a large discus buoy, 30 feet in diameter, and hosts generators for power, compressors for air, and a telemetry communications system.

During missions a surface-based support crew monitors the aquanauts and habitat 24/7 from a watch desk and command center at the shore base. Divers are available round the clock for emergencies and a workboat goes out to the site almost every day.

Size and Configuration

Aquarius is a three–part system, including the LSB described above, a 120 ton baseplate, which provides a stable platform upon which Aquarius is mounted, and an 85 ton “habitat” (underwater laboratories are often referred to as habitats) that provides living and working space for a six person crew. The habitat itself is a 9 feet diameter by 43 feet long steel cylinder that can support operations to depths of 120 feet. The habitat includes a seawater interface in a “Wet Porch”, and two pressure locks known as the Entry Lock and Main Lock, sized at 500 and 1400 cubic feet, respectively. Approximately 400 square feet of living and laboratory space is available for operations and science. The lab is equipped with computers networked to shore, internet, telephones, radios, video conferencing and broadcast equipment.

Operating Environment

Aquarius is normally an ambient pressure habitat, which means that the interior atmospheric pressure is equal to the surrounding water pressure. The entryway within the Wet Porch, called the moon pool, remains open as the equal air pressure inside prevents the water from flowing in. The baseplate rests in approximately 62 feet of water, with the habitat mounted off the bottom at a depth of approximately 47 feet (tidal range at the site is between two and three feet). This operating depth is referred to as “hatch depth”. The pressure at 47 feet of seawater is about 2.5 times greater than the atmospheric pressure found at sea level. At this depth and pressure, non-saturated visitors to Aquarius have less than about 80 minutes to visit and return to the surface before they risk experiencing decompression related illness. However, the mission aquanauts living in Aquarius can stay indefinitely and have 6 to 9 hours of diving down to about 95 feet each day, with unlimited time at storage depth. At the end of a mission, aquanauts undergo 15 hours and 45 minutes of decompression that is conducted within Aquarius itself, while on the bottom. At the end of decompression, Aquanauts exit Aquarius and scuba dive back to the surface.

Length of an Aquarius Mission

Aquarius missions typically last 10 days. We conduct shorter missions at the start of the year for training and to test systems. Typical missions in Aquarius are 14 days long. Interestingly, and this relates to the technique of saturation diving that we support, once you are saturated it doesn't matter if you stay one day, a week, or a month — the decompression time remains the same.

At the end of missions aquanauts decompress inside Aquarius, where pressure is slowly brought back to one atmosphere (or surface pressure) from the operating depth of about 50 feet — and it takes over 17 hours. Aquanauts then “lock–out” and swim to the surface. People sometimes think that Aquarius is brought to the surface during decompression, but it stays on the bottom; it’s the pressure inside Aquarius that is changed.

Additional Information

The Aquarius website contains detailed information about current science projects and mission schedules. A virtual tour, lesson plans, archives, and press room are also included. Web cameras operate during missions with cameras inside and outside Aquarius. Live broadcasts (webcasts and special videoconferencing opportunities) are frequently conducted that involve schools, museums, and aquariums across the country. Scientific missions in Aquarius are typically awarded through a peer review process when funding becomes available or through partnership and other funding mechanisms. For more information, or if you are interested in hosting a live program, please contact Thomas Potts, Aquarius Program Director .