A Canadian astronaut takes part in the underwater mission designed to give a taste of what it would be like in the space orbit and is currently living on the floor of the Atlantic Ocean.
Jeremy Hansen was currently on the floor of the Atlantic Ocean at the Aquarius Reef Base in Florida, 20m below the surface, Sky News reported.
The 38-year-old said that there's a hole in the floor that's open to the ocean all the time, and the air pressure keeps the water out, and they just go in and out.
Hansen, who's the exploration lead for NASA's extreme environment mission operations, has been tweeting images of his underwater adventure, including an early morning snap of a passing barracuda.