Six people have shut themselves inside a dome for a year in Hawaii, in the longest US isolation experiment aimed at helping NASA prepare for a pioneering journey to Mars.

Key points: Six people take part in year-long isolation

Six people take part in year-long isolation NASA studying how conflict scenarios play out

NASA studying how conflict scenarios play out "Cheap" simulation costing $1.6 million

"Cheap" simulation costing $1.6 million Conflicts found to arise in other similar simulation experiments

The crew includes a French astrobiologist, a German physicist and four Americans; a pilot, an architect, a doctor/journalist and a soil scientist.

They are based on a barren, northern slope of Mauna Loa, living inside a dome that is 11 metres in diameter and about six metres tall.

In a place with no animals and little vegetation around, they closed themselves in on Friday at 3:00pm Hawaii time, marking the official start to the 12-month mission.

The men and women have their own small rooms, with space for a sleeping cot and desk, and will spend their days eating food like powdered cheese and canned tuna, only going outside if dressed in a spacesuit, and having limited access to the internet.

Crew member Sheyna Gifford described the team as "six people who want to change the world by making it possible for people to leave it at will" in a post on her blog.

Architect Tristan Bassingthwaighte said he would be "studying architectural methods for creating a more habitable environment and increasing our capability to live in the extreme environments of Earth and other worlds", according to his LinkedIn page.

"Hoping to learn a lot!" he added.

The crew includes a French astrobiologist, a German physicist and four Americans; a pilot, an architect, a doctor/journalist and a soil scientist. ( AFP: Zak Wilson )

Conflicts in cramped space certain to occur

Any astronauts that go to Mars are facing a trip that would last far longer than the six months that humans typically spend at the orbiting International Space Station.

NASA's current technology can send a robotic mission to the red planet in eight months, and the space agency estimates that a human mission would take between one and three years.

With all that time spent in a cramped space without access to fresh air, food, or privacy, conflicts are certain to occur.

The US space agency is studying how these scenarios play out on Earth — in a program called Hawaii Space Exploration Analog and Simulation (HI-SEAS) — before pressing on toward Mars, which NASA hopes to reach some time in the 2030s.

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

NASA is spending about $1.6 million on these simulations and has just received funding of around another $1.4 million for three more in the coming years, according to principal investigator Kim Binsted.

"That is very cheap for space research," she said.

"It is really inexpensive compared to the cost of a space mission going wrong."

The men and women have their own small rooms, with space for a sleeping cot and desk. ( AFP: Zak Wilson )

Other simulation experiments have taken place under the ocean off the Florida coast, in Antarctica and in Russia, where a 520-day Mars experiment was carried out in 2011.

Ms Binsted said during the eight-month co-habitation mission, which ended earlier this year, conflicts did arise.

She said she could not go into detail about the nature of them without breaching confidentiality of the crew.

But the crew was able to work through their problems, she said.

"I think one of the lessons is that you really can't prevent interpersonal conflicts. It is going to happen over these long-duration missions, even with the very best people," she said.

"But what you can do is help people be resilient so they respond well to the problems and can resolve them and continue to perform well as a team."

Ms Binsted said the first scientific results from the missions should be made public about a year from now.

Jocelyn Dunn, a crew member from the previous mission, said she came to love the inside jokes among the crew, doing daily workouts, and learning to cook things like bagels and pizza dough with the ingredients on hand.

"I guess I got a taste of marriage, albeit a hexagon of relationships rather than a dyad," she wrote on her blog.

Then, just days after the mission ended in mid-June, she described the joy of being "on Earth" again, eating fresh vegetables, using a knife to cut meat, swimming, and drinking soft drink and champagne.

"I couldn't believe how much I had missed the flavours and textures of a juicy steak," she said.

AFP