Six researchers have spent the past four months living in a small dome on a barren Hawaii lava field at 8000 feet, trying to figure out what foods astronauts might eat on Mars and during deep-space missions.

They emerged on Tuesday with their recipes and without the space suits they were required to wear each time they ventured onto the northern slope of Mauna Loa – an active volcano that last erupted in 1984.

"It's a moment I'm going to remember for the rest of my life," said Oleg Abramov, a research space scientist at the US Geological Survey Astrogeology branch in Flagstaff, Arizona. "Walking out ... experiencing the sunshine and wind on our faces."

The six researchers were selected by the University of Hawaii and Cornell University for the NASA-funded study to prepare meals from a list of dehydrated, preserved foods that are not perishable. They examined pre-prepared meals similar to what astronauts currently eat and concocted meals themselves in an attempt to combat malnourishment and food boredom.