To date, no life has been found on the surface of Mars and for good reason. Observations from NASA’s various Mars missions indicate that it is very dry, with no surface water, a thin atmosphere and normal temperatures averaging well below zero.

It is possible that someday Mars may be made more hospitable to human life but early visitors and pioneers will have to survive in some harsh conditions. For the past four months, members of the second Hawaii Space Exploration Analog & Simulation mission (HI-SEAS 2) atop Hawaii’s Mauna Loa volcano, 8,000 feet above sea level, in an effort to simulate these harsh conditions.

The volunteers, Casey Stedman, an officer in the U.S. Air Force Reserve, Lucie Poulet, NASA scientist Anne Caraccio, spaceflight research assistant Tiffany Swarmer, Physics Ph.D. student Ross Lockwood, space-engineering Ph.D. candidate and neuropsychologist Ronald William lived in a two-story, 36-foot-wide, solar-powered dome. They only left the structure for simulated “Mars Walks”.

On Friday, July 25, the team webcast their “return to Earth”.

“I haven’t seen a tree, smelled the rain, heard a bird, or felt wind on my skin in four months,” said Stedman, in a statement.

NASA is preparing for its first manned missions to Mars in the 2030s and Mars One is planning on sending the first colonists in the 2020s. The simulated Mars missions will, no doubt, help these organizations to understand some of the challenges that humans will face on the Red Planet and hopefully avoid problems that may arise.

“In the last 60 days, the crew and I have faced power system failures, water shortages, illness, fatigue, electrical fluctuations, spacesuit leaks, medical emergencies, network dropouts, storms, habitat leaks, and numerous equipment failures. How the crew responds to each crisis will help future mission planners devise new techniques to mitigate risks and better prepare astronauts for the challenges of long duration missions,” said Stedman in a recent blog post.