• Graham Mann is a senior lecturer at Murdoch University in Perth, Australia.
Life on Earth has its challenges but what about life on Mars? Can humans ever survive on our neighbouring red planet?
To help answer that, an international crew of six people spent a year living inside a solar-powered dome on the barren slopes of Hawaii's Mauna Loa volcano.
It was the latest Earth-bound project from the HawaiI Space Exploration Analogue and Simulation (Hi-Seas), a Nasa-funded trial of technologies, systems and people for its future Mars mission.
The crew - an astrobiologist, a doctor/journalist, a soil scientist, an engineer, a physicist and a habitat specialist - emerged from the dome on Sunday, August 28, pale but triumphant from their mission during which they played out an elaborate and realistic game of planetary exploration.
Life in the dome
The crew spent most of their mission time working, playing and sleeping inside the 11m dome, all the while performing experiments, and having experiments performed on them.
They could leave the dome, but only in mock-up spacesuits, and never alone. They could communicate with the world by email and blogs, but the 20-minute delay representing the radio signal time delay across interplanetary distances made real-time conversation impossible.
They ate only canned or freeze-dried food, though they were able to supplement this with fermentation to make such delicacies as bread and cream cheese. They were allowed a total of eight minutes in the shower per week.
This has not been the only, or even the longest, Mars mission simulation. Hi-Seas itself has conducted three shorter missions before. Meanwhile in 2010, an international crew in Moscow stayed in the Mars 500 simulation for 520 days.
In September, Australians Jon Clarke and Annalea Beattie will join a 160-day simulation at habitats in Utah and northern Canada. The rationale is simple: to prepare for anything difficult or dangerous, you need to practise in conditions as close as possible to the real thing.
In Hi-Seas mission 4, the research was focused on human factors questions, in particular: how will a team of six people, more isolated than any in history, living in close proximity and carrying out difficult technical tasks, perform over time?
Some red flags had been noted in earlier missions. Russian crews on the Mir space station had sometimes become withdrawn and uncommunicative, even ceasing work altogether. Ground simulations had warned of the potential for serious cultural clashes among international crews, specifically around food and interpersonal etiquette.
For a space team, where the cooperation of every member is critical, such disharmony could be disastrous. Crews had also experienced a third-quarter effect, in which morale - and performance - dipped low at the 75 per cent mark.
The mission 4 crew, forewarned about these problems, experimented with solutions. The full results are not written up yet, but much can be seen in the crew blogs.
To overcome depression and withdrawal, and cement crew solidarity, the crew danced together, learnt new skills together and took turns creating semi-gourmet meals out of the limited rations.
To prepare themselves for an unexpected crisis, they practised getting by on reduced water rations. Later, when a water delivery failed to arrive on schedule, they were forced to draw on an old water tank that they feared had been contaminated.
They calculated their minimum requirements, which let them improvise an evaporative purification system that supplied enough water for the six to survive until they could be resupplied.
Still, critics complain and ask, what's the point of exploring Mars, anyway? We have pretty good pictures and science data already. Why spend huge sums on such a venture?
Shouldn't we wait until we've solved some of the pressing problems that face us on Earth first?
There are very good reasons for learning how people can travel, live, work and play beyond the Earth. This is not a pipe dream, it's a socioeconomic necessity. History shows the continuous and ongoing expansion of healthy human societies into new environments.
Staying put is not what humans tend to do, especially when resources and opportunities are limited. Increasingly, as the population (and our appetite for material things) grows, this puts us into conflict with others.
To suppress or delay an expansion away from our point of origin is to put unbearable constraints on human life in the future, and increase the risk of ever escalating territorial disputes, closed borders, hoarding and warfare.
A history of discovery
In Europe, 250 years ago, there was a red, dusty, alien environment out there on the frontier. Hostile, unknown, dangerous. Six months away on a ship, if you survived at all.
That was Australia. Now look at it.
A Mars colony would be a truly wonderful thing. A whole new branch of humanity, with its own customs, laws, science, business, music, art, dance and literature.
It would be an inspiration even to those who would never go. It would be giving something positive to the future, instead of always robbing it.