Legendary polar explorer Sir Ranulph Fiennes boarded a British Airways flight to Cape Town on Saturday, the first leg of an expedition he calls “my greatest challenge to date”.

Sir Ranulph is to take on one of the last remaining polar challenges by attempting to cross Antarctica in winter – the coldest journey on Earth.

BA is supporting the expedition by providing flights for Sir Ranulph and the five key colleagues who will accompany him on the 2,000-mile trek.

In Cape Town the team will rendezvous with the expedition’s South African ice-strengthened research ship the SA Agulhas.

After completing their preparations, the six expedition members will set out on a six-month journey to reach the Ross Sea on 21 March, 2013.

Their route from the Russian base of Novolazarevskaya (‘Novo’) to Captain Scott’s base at McMurdo Sound – via the South Pole – will test the limits of human endurance.

During this six-month period the expedition team will travel in temperatures as low as -90°C and mostly in complete darkness.

They will also have to be entirely self-sufficient and there will be no search and rescue facility available, as aircraft cannot penetrate inland during winter, due to darkness and the risk of fuel freezing.

Commenting on the Antarctic traverse, Sir Ranulph said: “This will be my greatest challenge to date. We will stretch the limits of human endurance. Britain and the Commonwealth has a strong heritage of exploration, from Captain Cook 300 years ago to the present day. As such, it is fitting that a Commonwealth team should be the first to fulfil this last great polar expedition.

“It is a unique opportunity to carry out a number of scientific tasks in the extreme polar environment, which will make a significant contribution to our understanding of the true effects of global warming on the Antarctic continent.”

Richard Tams, BA’s head of UK and Ireland sales and marketing, who set up the sponsorship deal, said: “We are very proud to be helping Sir Ranulph. He perfectly epitomises British Airways’ values of teamwork, innovation, passion and self-belief. And of course, like him we believe in stretching ourselves and going the extra mile or, in Sir Ranulph’s case, an extra 2,000 miles!”