Boredom was hardest part of year-long dome isolation: Nasa crew

In addition to insufficient stimulation, isolation and lack of fresh food and air were the toughest challenges.

Monotony was the hardest part of a yearlong Nasa experiment about the mental and psychological rigors of long term spaceflight,” crew members said after the test ended. The six-member crew emerged Sunday from a dome in Hawaii, on the barren northern slope of the Mauna Loa volcano, where they were studied as part of the US space agency's mission to send people to Mars by the 2030s. On Monday, US President Barack Obama congratulated them, writing on Twitter: "Congrats to Nasa and the scientists taking us a step closer to Mars. Now enjoy Hawaii and get a shave ice!"

In addition to insufficient stimulation, isolation and a lack of fresh food and air were the toughest challenges during the yearlong experiment, known as the Hawaii Space Exploration Analog and Simulation (HI-SEAS) -- the third and longest of its kind. The team locked themselves into the dome, located in an abandoned quarry far from animals and vegetation, on August 28, 2015.

"We were always in the same place, always with the same people," said French astrobiologist Cyprien Verseux in a Periscope interview by organizers posted on Twitter. The crew lived inside a structure 36 feet (11 metres) in diameter and 20 feet tall, emerging only if outfitted in spacesuits, never breathing the outside air or eating fresh produce. Verseux said the experiment shows that "a mission to Mars in the close future is realistic." He said a key hurdle involves producing food and a small-scale ecosystem on Mars, where the atmosphere is thin, the ground dry and water is scarce.

The experiment did not test the process of growing food, but was aimed primarily at the psychological study of the crew.

The men and women had their own small rooms, with space for a sleeping cot and desk, and spent their days eating food like powdered cheese and canned tuna. The dome had composting toilets and showers, and was powered by solar energy. Team members had limited Internet access and they could venture outside only in spacesuits.

Christiane Heinicke from Germany said that her main experiment was extracting water from the ground -- adding that the volcanic soil on Mauna Loa is very similar in mineral composition to the Martian soil.

“You can actually get water from a ground that is seemingly dry,” she said. “The implication is that you could get water from Mars.”

The crew also included a pilot, a doctor/journalist and a soil scientist. The full analysis of the team's psychological performance has yet to be revealed, but it is expected to be published in the coming months. Nasa is studying how these long-term isolation scenarios play out on Earth before pressing on toward Mars, which the US space agency hopes to reach sometime in the 2030s.

Nasa can currently send a robot to the Red Planet in about eight months, but astronauts traveling to Mars face a trip lasting between one and three years.

The first HI-SEAS experiment involved studies about cooking on Mars and was followed by a four-month and an eight-month cohabitation mission.

Two more HI-SEAS missions are presently being planned starting in January 2017 and 2018. Both missions are scheduled to last eight months.