After 31 days underwater, Fabien Cousteau and his crew are about to become land dwellers again.
An ocean explorer and filmmaker like his famous grandfather Jacques, Cousteau will ascend Wednesday morning from the world's only undersea lab, Aquarius Reef Base.
Since June 1, Cousteau and his fellow aquanauts have been living mostly on freeze-dried food and conducting scientific research on the marine life and themselves -- all the while broadcasting the mission live online from the school-bus-size lab.
Known as Mission 31, it became the longest-running expedition at the Aquarius habitat, which sits 63 feet below the surface near a coral reef in the Florida Keys National Marine Sanctuary. (The next longest was a special NASA training mission that ran 18 days.) The mission comes half a century after Jacques Cousteau led a similar expedition in undersea living known as Conshelf Two, which took place 33 feet below in the Red Sea.
Going weeks without sun and fresh air and living in tight quarters, the aquanauts' biggest challenge may have been time itself.
Living at the habitat means aquanauts can dive up to nine hours a day, enabling them to conduct research that might normally take several months in only a few weeks. But it turns out that living underwater for 31 days goes by quickly when you've got a full calendar.
"Maybe this should be Mission 62, instead of Mission 31," Cousteau said in an interview with CNET about two and half weeks into the expedition.
In addition to conducting scientific research on how climate change, overconsumption, and pollution are affecting the health of the ocean, the crew also filmed footage for short- and long-form documentaries. Then there were the Skype sessions with schools and museums and Google Hangouts with policymakers and scientists. There were plenty of special visitors too -- among them Cousteau's father, Jean-Michel, and Sylvia Earle, a pioneer in ocean exploration known as "Her Deepness." Even a few Hollywood heartthrobs showed up at the habitat, including Ian Somerhalder of "Vampire Diaries."
Mission 31 went deeper and one day longer than Conshelf Two in a nod to Jacques Cousteau's legacy. But a larger aim of the mission was to highlight the "human-ocean connection," Fabien Cousteau said in an interview last year. And that's why having an underwater habitat like Aquarius is so important, he said.
"You're able to discover a lot more," Cousteau said, "discover new species and the interconnectivity and the wonders of our one and only life-support system, which is this planet and why it is that it's important for us to pay attention to it."