On the surface, it might not sound like a place for astronauts, but it makes sense once you dive in.
Canadian Astronaut Jeremy Hansen will surface Sunday after spending a week living 19 meters (62 feet) under the sea, as part of a NASA mission.
The London, Ont., native tweeted Saturday that he was “excited” for his last full day, though it was also “bittersweet.”
The excusrion was part of the NASA Extreme Environment Mission Operations program – dubbed NEEMO.
The program sends groups of astronauts, engineers and doctors to live in the Aquarius Habitat, which sits on the sea floor 5.6 km off the coast of Key Largo, Fla.
Underwater crews are able to simulate low-gravity environments to practice what it would be like to work on the moon, Mars or asteroids. The isolated environment similarly mimics those of space missions.
Hansen served as exploration lead for the NEEMO 19 mission crew of six. He was responsible for preparing and executing spacewalk-simulating dives. Over the week, he made four dives during which he tested equipment, explored the ocean floor and relayed results to other members of the crew.
On a night dive Thursday, Hansen tweeted: “1st thing I did was walk 2 end of umbilical away from habitat & turn off light. Pitch black & alone on sea floor. Eerie & humbling.”
He also happily reported: “Back alive with all body parts! Night dive as cool as expected.”
The crew also simulated a 10-minute round-trip communications delay with mission control – as astronauts operating in deep space would experience, due to the vast distances between Earth and the spacecraft. This meant the crew were forced to address problems without immediate help from mission control.
The Aquarius Habitat is 3 metres wide by 14 metres long and maintains an internal pressure matching that of the surrounding water, meaning crews can stay at-depth indefinitely. The cost of long stays at such high pressure, however, means that crews must spend 17 hours in a decompression chamber prior to returning to the surface.