JOHANNESBURG — It’s a six-month expedition in almost constant darkness, in the coldest place on the planet, with no chance of rescue if things go wrong. British explorer Sir Ranulph Fiennes calls it one of the last remaining polar challenges: crossing Antarctica during the region’s winter.
Against the backdrop of Cape Town’s majestic Table Mountain, Fiennes, 68, and his five-member team left the South African port city on Monday aboard a South African polar vessel, the Agulhas, for what they have dubbed ‘‘The Coldest Journey.’’
After reaching the southernmost continent, the expedition will begin its journey via the South Pole on March 21, traversing nearly 2,500 miles in a place where temperatures often dip as low as minus 90 degrees. Antarctica has recorded the lowest temperature anywhere on the planet — a shocking minus 128.5 degrees.
The trip is particularly hazardous because no aircraft can travel inland in the winter due to the darkness and risk that fuel will freeze, meaning there is virtually no chance of a search-and-rescue operation if disaster strikes.
Even Fiennes, who has spent a lifetime embracing peril, is circumspect. ‘‘I usually look forward to expeditions, but there is such a big degree of uncertainty with this one that looking forward to it is probably not the exact right word,’’ Fiennes said, according to the website of SABC, South Africa’s state broadcaster.
‘‘Some people will say it is irresponsible to go unless you know everything, in which case the Americans would never have gotten to the moon. If humans are going for something new, then unfortunately there are bound to be some gray areas,’’ Fiennes said.
Satellite and other communications technology will allow the team to communicate with the outside world and to provide updates on its progress.
The team’s gear includes battery-operated heating mechanisms in clothing and special breathing apparatus. Modified 20-ton tractors will transport sledges with mounted living quarters and fuel that is designed not to freeze in the extreme temperatures.