Walking alone through the Australian desert without any support would push anyone to the edge, physically and mentally. But Jon Muir says he thrives on a good challenge.
One of the greatest adventurers of modern time, Illawarra-born Jon Muir, has a giant map of Australia which is defined with lines of all the routes he has already walked.
There are lines radiating from the geographic centre of Australia and more all the way from Port Augusta, SA, to Burketown in north-western Queensland.
Yet the large deserts in Western Australia - replete with sandhills, rock formations and kilometres of spinifex - were looking a little bare on Muir's map.
"It's a bit unbalanced," he says. "I need a big line out in the west of the continent or I feel as if my map might suddenly flip over.
"The western desert is an obvious challenge and I'm taking it up because I want a really huge challenge. It's time."
Muir, who jokes his must-do list on the planet stretches 10,000 lifetimes long, is planning to cross the Gibson and Little Sandy Deserts on foot without any external support.
"The challenges that these vast deserts present to the unsupported walker places this traverse at the cutting edge of world adventure and pushes the limits of human endurance," he says.
The 53-year-old adventurer is still working on the specific details and the precise route of the trek which he anticipates will be 900km, and taking about 50 days to complete, during the winter months of this year.
"It's fairly slow going out in that desert country at times when you've got a fair burden to bear," says Muir by phone from his 60ha property at the foot of the Grampians, where he lives with wife Suzan Muir.
"I will be off track and it's pretty slow going through spinifex. It's a very challenging sort of situation."
Muir will be attempting an unsupported walk across the deserts, hauling a wheeled cart behind him which will carry large quantities of water and supplies.
"It will be just me and my energy, traversing across untracked desert," says Muir whose adventures span 40 years.
"I won't be following four-wheel drive tracks or anything like that.
"I'll be going cross country with no beasts of burden, no pre-laid food depots, and no re-supplies.
"It will just be me with what I start with and what I can get from the natural environment on the way."
Muir has completed more than 10,000kms of unsupported walking in Australia's deserts and has never run out of water.
He is planning on drinking and gathering water from the widely spaced traditional soaks and rock holes of the Ngatatjara, Ngaanyatjarra and Mardu people.
"Water is a major concern in the desert when you are alone with no backup so I've got to play my cards right," he says.
In the months before his walk, planned for July and August, Muir will research the route, prepare his equipment, and build a new wheeled cart specific for the spinifex terrain.
Yet there won't be any physical training for the man who made the first ascent of Everest from the south without the aid of Sherpas, arriving at the summit alone; pioneered a new route to the South Pole, and completed an unsupported trek to the North Pole.
He has also travelled more than 5000km in a sea kayak, and in 2001 became the first person to walk across the continent of Australia without resupply or any external support, which became the subject of the award-winning documentary film Alone Across Australia. He is also the author of a book with the same title.
"I haven't done any specific training since prior to my attempt on the west ridge of Everest in 1984," he says. "Over 31 years since then, I haven't done any training.
"I trained when I started climbing in the mid 1970s through to 1984 but then I found because I was doing so much of it and had a physically active lifestyle I could maintain a very strong level of fitness without training."
Muir is a yoga devotee and keeps active with the work associated with maintaining his property.
"We've got a big garden and we are reasonably self reliant with food, energy and water," he says.
In between the big expeditions, he also does smaller walks.
Walking, it seems, is in the Muir bloodline. Muir's mum Margaret Muir, 92, who still lives in the Illawarra, walks a few kilometres every day and breaks into a run for 100m of her walk. His father Bob has passed away.
Fitness is important yet Muir says the mental approach plays a bigger role in being able to survive in the world's harshest environments.
"The crux of the expedition is in your attitude and where you are at inside your head, especially on solo journeys," he says.
"If you don't get that right then it doesn't matter how fit you are, it doesn't matter how strong you are, if you haven't got it together in the head then things will fall apart."
Muir says there are enormous physical and emotional challenges pushing yourself to the limits of endurance.
"Some people can lose the plot a bit I think," he says.
"It happens fairly regularly, especially alone, but not necessarily alone.
"I've seen lots of people crack on expeditions over the years, especially the long ones that can go week after week. They tend not to be able to sustain it mentally."
Muir, who is also a motivational speaker, says one of the most basic things to consider before embarking on any venture - be it walking across a thin skin of ice in the Arctic or enrolling in university studies - is that you have chosen that path.
"You've got to keep in mind that this is your choice," he says.
"When things get hard out there, in whatever it is you are doing, if you have chosen to do something that is difficult and challenging then you've got to expect to be challenged.
"I sometimes feel that that can be a little bit overlooked, when things get hard people tend to fall apart even though they have chosen that course or that line.
"So bear that in mind that when things do become a bit difficult it's good to remind yourself that you chose something difficult.
"Some people realise that they are not really cut out for it, and so be it, or that it was all a bit more difficult than they anticipated and they drop out of their course of study, or whatever it is they might do, or it's not right for them and that can be a wise choice."
Yet Muir thrives on intense challenges and pushing himself to the limits.
The warmer environment will create numerous challenges for the adventurer who will need to work physically hard, pulling along the heavy laden cart.
"The deserts are a more challenging place to travel through on foot than the polar regions," he says.
"People say: 'Oh, I don't like the cold' but if you are doing hard physical labour minus 30 degrees is a fantastic temperature to do it in.
"It doesn't get much better than that if you are doing really hard physical labour because you hardly sweat and the cold tends to keep your core temperature low and you don't overheat.
"Plus-30 degrees and doing hard physical labour is not nice."
Water is also guaranteed at the Poles or in high mountainous terrain, where ice can be melted.
Aboriginal communities lived in the western deserts, backed by tens of thousands of years of experience handed down through generations, and have crossed the deserts on foot.
Muir aims to be the first person since European settlement to cross the western desert solo and unsupported and without the aid of camels, horses or motor-powered vehicles.
"People have walked, for example the Canning Stock Route, but they have re-supplied along the way," he says.
"I won't be relying on a bulldozer in the sense that I will not be walking on a vehicle track.
"I won't be relying on water from bores ... I will be untracked and relying on what I find in the natural environment."
Muir is the recipient of three medals; an OAM in 1989 for services to mountaineering, a Centenary Medal in 2003 and he was named Australian Geographic Society's Adventurer of the Year in 2001.
The former Figtree High School student first showed his adventurous streak around the age of 11, during a family holiday to Canada and Scotland.
The turning point came when Muir read Sir Chris Bonington's Everest the Hard Way as a teenager. That was when he decided he wanted to become a mountaineer.
Over the past 30 years, many world adventurers including Muir have increasingly tried to strip away the paraphernalia which has enabled humans to explore the planet.
The concept of unsupported - only human powered expeditions - started to take off in the 1970s and 1980s.
"It's certainly not for the faint-hearted," he says.
"People wanted to know could they climb Everest without big teams of Sherpas carrying all the gear?
"Could they reach the South Pole or the North Pole without teams of huskies or tractors? People have been pursuing this purer simpler approach for a while and I've been one of those people doing that.
"And that's where the focus of my attention has tended to lie."
■ More information about Muir's next expedition can be found here.