Six crew members who spent eight months in isolation on a remote Hawaiian volcano - one of the world’s largest active volcanoes - will emerge from their Mars-esque habitat and return to Earth on Sunday.

The experiment was specially designed to replicate conditions on Mars, and to test the social and psychological effects a real manned mission to the red planet would pose to humans.

The research subjects, two men and four women, were cooped up in a small 1,200 square-foot (111-square meter) dome, except for excursions to explore the simulated Martian landscape.

Throughout the mission, crew members had to follow protocols simulating their life on Earth’s closest planetary neighbor, including eating “shelf-stable” food fit for space travel and donning astronaut suits when leaving their living quarters.

All communications to the team were subject to a 20-minute delay, the time it would take messages to travel from Earth to Mars.

Crew members wore sensors to gauge their moods and proximity to others. Among the sensor’s functions was monitoring the crew's voice levels and detecting whether people were avoiding one another.

This is the fifth such mission undertaken by the Hawaii Space Exploration Analog and Simulation (HI-SEAS), based at the University of Hawaii. NASA has earmarked roughly $2.5 million for studies at the facility.

“This is our fifth mission, and we have learned a lot over those five missions. We've learned, for one thing, that conflict, even in the best of teams, is going to arise,” project lead investigator Kim Binsted said, according to AP.

“So what's really important is to have a crew that, both as individuals and a group, is really resilient, is able to look at that conflict and come back from it,” she added.



Just like Mars? NASA team to spend 8 months on top of Hawaii volcano https://t.co/d8N1TZJB9Opic.twitter.com/VBxbP9GLWx — RT (@RT_com) January 30, 2017

It is hoped that the data gathered, and the insights of the crew members, will be used by NASA to select astronauts for a manned mission to Mars, hopefully by the 2030s.

Crew member Laura Lark thinks this is a realistic goal for the space agency.

“Long term space travel is absolutely possible. There are certainly technical challenges to be overcome. There are certainly human factors to be figured out, that’s part of what HI-SEAS is for. But I think that overcoming those challenges is just a matter of effort. We are absolutely capable of it,” she said from within the dome.

The university is currently making plans for a sixth mission, the last one funded by NASA.