A Nepali Sherpa is hoping to become the fastest person ever to climb Mount Everest.
Lhakpa Gelu Sherpa hopes to scale the 8,850 metre (29,000 feet) mountain in less than 15 hours.
Lhakpa Gelu has already climbed Everest nine times
The current record stands at 16 hours and 56 minutes and was set by another Nepali Sherpa in 2000.
Lhakpa Gelu is hoping to make the ascent from the base camp at around 5,300 metres (17,500 feet) to mark the 50th anniversary of the first time the mountain was climbed.
"From my experience of previous climbs, I know I can do this," he said before setting off for the base camp on Friday and added: "I know Everest like my own backyard."
Lhakpa Gelu has already climbed the world's highest mountain nine times and aims to climb it twice this year, once with a group of western climbers and again to make the record-breaking attempt.
He first climbed Mount Everest in 1993 with a British expedition and has repeated the feat almost on an annual basis.
It takes most climbers around four days to climb from the advanced base camp to the peak.
Lhakpa Gelu hopes to make the climb in mid-May when the weather conditions are more favourable.
He intends to take the traditional southeast ridge route on the Nepalese side of the mountain.
This is the same route taken by New Zealander, Edmund Hillary and Sherpa Tenzing Norgay on the first successful ascent of the mountain in 1953.
The current record for the fastest ascent of Everest was set by another Sherpa, Babu Chhiri almost three years ago.
Babu Chhiri died in a climbing accident a year later.
The mountain has been climbed by more than 1,250 people in the last 50 years and around 200 climbers have died.