Fiennes, 62, is scheduled to leave for Nepal Wednesday, The Independent reported.
In addition to the usual obstacles, Fiennes faces a political one. The Chinese government has closed access to Everest because the Olympic torch is scheduled to be brought up the mountain.
Fiennes plans to be in Nepal in case the mountain opens up.
Fiennes will be leaving his second wife, a woman he met and married after his childhood sweetheart died of cancer, and a 2-year-old daughter. The explorer's own father was killed in Italy during World War II four months before Fiennes was born -- but he told the Independent he is not that concerned about leaving his daughter without a father.
"I was born with no father ... but with a lovely mother," he said. "My daughter has got a lovely mother. Louise is an incredibly good mum."
In 2005, Fiennes collapsed about 1,000 feet short of the summit of Mount Everest. A Sherpa guide was able to get him down.