One major polar challenge remains left to achieve, and 68-year-old British Expeditioner Sir Ranulph Fiennes and his crew are determined to change that.

Fiennes and his five colleagues will embark on what they are calling "The Coldest Journey," a winter expedition across Antarctica beginning March 21, 2013.

The team seeks to spend six months traveling nearly 2,000 miles, crossing the polar plateau at an average height of 10,000 feet above sea level.

Most of the journey will be made in complete darkness, with the possibility for temperatures to drop as low as 130 degrees below zero F.

"There is no colder part of the Earth than the surface of the Antarctic icecap in winter," Expert Senior Meteorologist Jim Andrews said.

"Nearest rivals to the Antarctic icecap, with respect to deep cold, would be the Greenland icecap, which has no permanent inhabitants, and the Siberian 'Pole of Cold,' located in northeastern Asia," Andrews said.

Two towns in the Pole of Cold lay claim to the lowest temperature in an inhabited place, Oymyakon, 96 degrees below zero F, and Verkhoyansk, 90 degrees below zero F. Typical lows, however, are more like 50 degrees below zero F to 70 degrees below zero F during the depths of winter.

The risk is high for expeditioners on "The Coldest Journey," as emergency rescues are not possible during the Antarctic winter.

Air travel is too risky in constant darkness, and the extreme temperatures during the winter months are low enough to freeze fuel.

Previously, no expedition has ever ventured farther than 60 miles into Antarctica during the winter, but the team plans to do more than set a new record. Fiennes and his colleagues will undertake many research responsibilities, such as gathering unique data on marine life, oceanography and meteorology.

Additionally, the crew aims to raise $10 million for a global initiative called "Seeing is Believing" (SIB) to help prevent avoidable blindness in developing nations.

This is not the first journey for Fiennes with so many inherent risks. Previously, he has succeeded in running seven marathons in seven days on seven continents, summiting Mount Everest and becoming the first person to completely cross the Antarctic continent on foot.

In completing these expeditions, Ranulph has raised millions for various U.K. charities.

"We have only been able to get here today after five years of intensive planning," Expedition Co-Leader Anton Bowring said on the team's blog. "Don't underestimate the amount of work that has gone into this."

From (find the original story here); reprinted with permission.