Everything Felicity Aston has done in her career has been about testing how far she can push herself.

She has raced on skis in the Canadian Arctic, led a team of women across Greenland, searched for meteorite craters in Quebec and completed the infamous Marathon des Sables, which the Discovery Channel called “the toughest footrace on Earth”.

But on a solo skiing expedition across Antarctica, the 34-year-old realised she had reached the limits of her endurance.

On January 22 last year, Aston became the first woman to complete the feat, covering 1744km from the Ross Ice Shelf to the Hercules Inlet on the Ronne Ice Shelf via the South Pole.

She spent 59 days pulling two sledges across one of the world’s most inhospitable climates without seeing another human being. No amount of psychological training could have prepared her for the trip.

“I was shocked by just how awful it felt watching the plane disappear and knowing that the closest person was probably 700km away from me.

“I knew it would be very difficult for the plane to get back – just getting me there had meant a week of logistical planning, two planes and two fuel drops – so I knew they couldn’t come and get me unless it was a life or death emergency. Then the weather became so bad that there was no way a plane could have landed even if it had tried to.

I realised then what it meant to be totally reliant on oneself.

I knew I was the only person who could get me out of this.”

All the tools and techniques she had been taught by a psychologist before she embarked on the journey went straight out of the window.

“There was a lot of crying.

Every morning I’d sit in the tent listening to the noise of the wind, which reminds you what you’re about to propel yourself into, and every fibre of me didn’t want to go out there and spend another day on my skis.”

Then there was the fear; she told one newspaper she was “permanently scared for two months”. Everything from crossing crevasses to running out of the matches she was forced to use when her lighters stopped working presented the possibility she would die out there.

She faced temperatures of more than -30 and recalls being hit by winds which threatened to rip her tent apart, leaving her completely exposed to the elements.

To her surprise, it was resentment rather than optimism that propelled her onwards. “I started thinking about people who hadn’t been supportive of me in all sorts of ways – old colleagues who’d thought I couldn’t do it, people who’d left me indignant or hurt.

I didn’t want them to be right about me and I knew that meant I had to finish this.”

Aston remembers the moment she let herself believe she was going to make it. It was a terrible day – “The sky was grey and the landscape was featureless – just spongy nothingness, totally disorientating.”

In the distance she saw “two hazy blobs” which she suddenly realised were the coastal mountains on the far side of Antarctica. Again, she cried.

“That was genuinely the first time I allowed myself to even consider the possibility I’d reach the far coast. I couldn’t think about the end because it was too emotionally challenging.

I could only think about the next day. I changed from thinking like that to thinking there was no way I was going to leave without reaching those mountains.”

The relief when she finally made it was “indescribable”.

The expedition had been around a decade coming and to have completed it when she had doubted she could has left her with a lingering confidence.

“It’s not that I now have no fear but I’ve noticed a calmness in myself when approaching new challenges. I know I can get to a pretty extreme point and yet still be okay. The trip reaffirmed my belief that our bodies and brains are far more resilient than we give them credit for.”

She had been thinking about the expedition for years. Aged 19, she won a place on an expedition to Greenland with the British Exploring Society, which ignited her fascination with the Arctic landscape.

On leaving university with a degree in applied meterology, she landed a job with the British Antarctic Survey and was sent to a research station in Antarctica for three years where she monitored ozone depletion and climate.

She has gone on to lead numerous expeditions of her own, crossing Greenland in a four-woman team recruited from a local newspaper ad, skiing the frozen Vilyuy river in Siberia and leading eight women from Commonwealth countries in a journey across the Antarctic.

She has worked as expeditions officer for BSES Expeditions, the oldest youth development charity in the UK, and picked up a list of awards for her projects including the Captin Scott Society Spirit of Adventure Award.

She sits on the Council of the Young Explorer’s Trust and is an ambassador for the British Antarctic Monument Trust.

“I think it comes down to being curious,” she says of her amazing adventures. “I want to know what’s over the horizon.

After that very first expedition in Greenland, I’ve had a natural curiosity to find out how far I can go.”

The Commonwealth trip was challenging; many of the women involved had never done anything like it in their lives and it was up to Aston to lead them and keep them going.

“But I kept wondering what it would be like to be there without a team, to be alone.”

The idea wouldn’t go away – usually a sign that something is worth pursuing, she says.

“When it gets like that, you have to do something about it.”

Although exploring seems an unlikely career for most, Aston is a firm believer that anyone could do what she does. She points to that initial expedition with the British Exploring Society: “Anyone could apply for it, although of course you have to fundraise to cover the costs.”

She won an RAF scholarship when she was younger and now holds a private pilot’s licence. “I’d heard they offered them, was interested and applied for a place. I do believe you have to go out there looking for opportunities. If what you want doesn’t exist, you have to try to create that opportunity. If I think of an expedition I want to do, I’ll ask lots of questions and do lots of research until I’ve found a way of making it happen.”

She is set to spend the next few months on more familiar territory, touring the UK to promote her new book Alone In Antarctica, and spending time with her partner Pete at home in Kent.

Is it hard adjusting to normal life after living in such extreme conditions?

I’m reminded of the way astronauts are reported to struggle on returning to Earth after seeing it from above.

“I think some people do come back feeling a huge sense of anticlimax and begin questioning everything about their normal lives. But I know that when I’m on a trip, I’ll think of nothing but home and when I’m at home, I’ll be planning my next trip and I need both those things for balance.

“When you’re skiing into a blizzard completely alone, knowing all you have to look forward to is a cold tent and a cold dinner, the greatest achievement in the world seems to be going home to a loved one and snuggling up on the sofa with a glass of wine and a film.

“Going away makes me value what I have at home and being at home helps me to value how amazing it is that we live on this incredible planet and that there is always so much more to see.”

*Felicity Aston will talk about her adventures in Antarctica at Shoreham’s Ropetackle Arts Centre on Tuesday, June 4, at 7.30pm. Tickets cost £10. Visit www.ropetacklecentre.co.uk or call 01273 464440.

*Alone In Antartica is out on August 5, published by Summersdale.

Saturday