NASA has thrown together four astronauts into an underwater tin can -- well, OK, a habitation module -- sitting on the seafloor a few miles off the Florida Keys for a nine-day stretch beginning this week.
The goal is to test some new equipment and procedures, but experts say the real payoff may be in figuring how people get along under pressure, just like a long-duration flight to Mars or beyond.
The NEEMO project (NASA Extreme Environment Missions Operation) is one of several "space analogs" or trial runs for space here on Earth. Others include installations are in Antarctica, the Arizona desert, Devon Island, Canada; and Mauna Kea, Hawaii.
"For any kind of exploration they are essential," said John Rummel, biology professor at East Carolina University and former NASA senior astrobiologist. "You don't want that someone going into a difficult situation without the ability of the control center to fix anything to happen for the first time on surface of the moon or Mars."
Still, going 69 feet underwater is not like going into space. The buoyancy is different, the water provides resistance, divers are on hand to help the "aquanauts" suit up and accomplish certain tasks when they leave the module. And there are fish swimming around.
Perhaps the biggest space analog is the crew, according to Akihiko Hoshide, commander of the four-person team and an astronaut with Japan's space agency, JAXA.
Hoshide spoke to Discovery News from his underwater home for the next nine days. "We are living and working together and the schedule is pretty tight," he said. "There are some malfunctions here and there and then you have to deal with it. In that aspect, it really is close to spaceflight."
Hoshide should know. He spent more than four months on board the International Space Station in 2012.
NASA Astronaut and Army Col. Mark Vande Hei is working on so-called "human factors," such as how to deal with a 10-minute delay between ground control and someone doing a spacewalk to collect rocks. That's something he expects to do on a possible NASA mission to land on an asteroid.
Over the next few days, the NASA crew, will be learning to get along in the tight quarters of the 43-foot long, 9-foot wide Aquarius module that includes lab space, computers, power and life support, and kitchen and bathroom facilities. A second NASA team is scheduled to use Aquarius, which is operated by Florida International University, in August.
Despite the political and financial uncertainty about the future of NASA's human spaceflight mission, Rummel said there's another reason to put crews together in tough situations: it breeds leadership.
"Expedition leaders are much better at picking teams than anyone else," Rummel said. "To get expedition leaders into the astronaut corps, the analog is the only way to do it. That's why you go to those places that are demanding and not personable environments."