Two women are due to set off at midday today in a race to become the first female Briton to complete a solo trip to the South Pole.
Rosie Stancer, 43 and Fiona Thornewill, 37, were making their final preparations last night in Patriot Hills, Antarctica, to race each other after spending 24 hours adapting to temperatures as low as minus 40C. Their arrival from the relatively milder climes of southern Chile was delayed when they were stranded by high winds for a week.
The two women will fly to Hercules Inlet at the edge of Antarctica where they will part and begin the 700-mile trek alone, pulling sledges double their weight without dogs or emergency supplies. They aim to emulate the feat of Norwegian Liv Arneson who became the first woman to make the solo trip in 1994.
Ms Thornewill, a recruitment consultant from Nottingham, said: "It's the greatest challenge I'll ever undertake for sure but I'd be a liar to say I wasn't nervous about it. Sometimes the thought of walking 700 miles through Antarctica really excites me and other times I wake up at night and it daunts me."
Her husband, Mike, is leading six novices on a parallel expedition on the uncompleted 97-mile stage of Sir Ernest Shackleton's original 1907 route to the South Pole.
Until this summer, the women were unaware that they were attempting the journey at the same time and have played down any rivalry.
Ms Stancer, a freelance writer from London and a cousin of the Queen, said it was "genuinely great" and "reassuring to know there is another woman out there on her own". They estimate it may take up to 70 days to complete the challenge and must reach the South Pole before the weather closes in. Both will live on diets of 5,000 calories a day, including chocolate bars, nuts, six litres of water and dehydrated meals.
All funds raised from Ms Stancer's challenge will go towards the Special Olympics while Ms Thornehill hopes to raise a six-figure sum for the NSPCC and Macmillan Cancer Relief.
The women flew to Antarctica with veteran explorer Pen Hadow and businessman Simon Murray, 63, who aims to become to oldest person to complete the trek. Mr Murray, who is based in Hong Kong, spent five years with the French foreign legion and wrote of his experiences in his book Legionnaire. He was also group managing director of Hutchison Whampoa for 10 years. He said: "Over the past 18 months, I have trained on a daily basis with this arduous trek in mind. While I feel as well prepared as I will ever be - having trained in the North Pole earlier this year - I appreciate that Antarctica is unrelentingly inhospitable."
This spring, Mr Hadow, 41, from Hexworthy, on Dartmoor, was the first person to trek solo without resupply from Canada to the North Geographic Pole. The Tetley South Pole Mission will raise funds for the Royal Geographical Society's polar archives.