A 19-year-old former Eton College student has become the fastest person ever to reach the South Pole - arriving on Christmas Eve.
Parker Liautaud skied to the tip of the Earth from the Antarctic coast in just 18 days, smashing the record of 24 days held by Norwegian Christian Eide.
He has also become the youngest man ever to achieve the feat.
Yesterday MailOnline exclusively revealed the quest by the teenage environmental campaigner, who has already been on three expeditions to the North Pole, the first when he was just 15.
He said after reaching the Pole: 'The whole journey is really a mental one, managing uncertainty and trying to figure out how to manage risk.
'It is really a big relief to know that we have done it.'
The teenager said the most challenging part of the expedition, which he undertook with his companion Doug Stoup, was the 'mental game' he had to play.
'It was difficult to really not see the expedition as one big countdown to the South Pole,' he said.
'It was important to break it up in to manageable chunks. That is really the only way to get through - take it milestone by milestone.
'I am very lucky to have had the opportunity to do the expedition. I feel fantastic. It could have gone either way.'
The half-French, half-American teenager, who moved to London from California aged nine, now plans to take a well-deserved rest - saying he hoped to spend Christmas Day asleep.
'I have lost around 20lbs and I've only eaten nuts and dried food for the last month,' he said. 'I am really looking forward to having my first proper meal.
'I know it will be the best feeling waking up on Christmas Day knowing I don't have to walk another 17 miles.'
Mr Liautaud is believed to be the youngest man ever to ski to the South Pole, but not the youngest person: that honour was claimed by 16-year-old British schoolgirl Amelia Hempleman-Adams in 2011.
And British schoolboy Lewis Clarke, 16, is currently trying to break that record and was almost halfway to the South Pole yesterday.
But his mission has been delayed by a broken ski - meaning Lewis will have to walk for the next two days while he waits for a flight to drop a replacement.
On day seven of the expedition, Mr Liautaud wrote that chilling winds measuring up to 46mph (74km/h) had been blowing in his face.
‘We had a whiteout for most of the day and near the end of the day it wasn’t really possible to see anything,' he said. 'I could hardly see the skis on my feet and lost Doug [his expedition partner] a couple of times.’
'It's more frustrating than frightening - it makes navigation difficult... I really hope the whiteout goes away - it's really not my thing.'
He described the weather conditions as ‘very difficult’ and said: ‘Some of the issues I’ve been dealing with – pain in my ankle caused by the way I’ve been walking…as well as the rash and back pain and all the minor things come with a vengeance.’
While it is easy to imagine Antarctica as a huge white expanse, Mr Liautaud said that he has been suffering with altitude sickness and is short of breath as he is walking around 2,622m above sea level.
Together with his team, he flew to Union Glacier before travelling 1,900 miles to Leverett Glacier in a custom-built ‘Ice Broker’ 6x6 Toyota Hilux truck kitted out with scientific and communications equipment and laden with life-preserving supplies.
However, from there, he and his teammate Doug Stoup, swapped to skis in attempt to set a new ‘coast to pole’ speed record without help from any external sources.
It is easy to forget, given the incredible journey Mr Liautaud has embarked upon, that he is a normal teenager who enjoys hanging out with his friends in his dorm room and reads notes from his parents to lift his spirits on the long trek.
He spends a lot of time thinking about food because he only has limited supplies of freeze dried food and nuts.
'But it's mainly because I spend a lot of the day being hungry. It's been a month since I've had normal food...and I'm losing a lot of weight,' he added.
Mr Liautaud and Stoup each pulled an 82kg sled, or pulk, consisting of equipment and supplies, while the truck following them films their endeavour – skiing for 12 hours, 18 miles (30km) a day and setting up camp for four
He said the freshly blown snow made it especially difficult to pull sleds through, much like dragging feet through sand.
Mr Liautaud said: ‘Every step is another one in the bag and the most important thing is to stay positive.’
The pair tackled the 'remarkable' Trans-Antarctic Mountains, which at their highest point tower 14,855ft (4,528m) and ate a staggering 6,000 calories of food to keep their energy up every day.
Mr Liautaud trained hard in between studying and attending lectures, fitting in gym work-outs, long runs and tyre pulling sessions to prepare himself for the trek and as well as building his strength and stamina, he worked on his flexibility as sprains or tears could end his record bid.
It’s dominated my life from physical and mental training to the science and skiing,’ he told MailOnline.
He has trained for at least 12 hours a week for months on end in order to ‘deal with the discomfort so it doesn’t block me from reaching my goal.’
Despite his intensive preparations, truck crew member Nathan Hambrook-Skinner, said that just before the half way point of the expedition, Mr Liautaud was ‘battling nagging back pain and a raw sweat rash.
‘I can’t come close to expressing the kind of physical pain that Parker must be experiencing after 12 plus hours of skiing across rock solid snow and ice, tugging an immense pulk,’ he said.
Mr Liautaud has talked about being ‘consistently frozen to the bone’ and 'losing every ounce of energy and becoming kind of useless towards the end of the day.’
He told MailOnline that it is hard to describe just how cold temperatures of -50°C feel like but the most noticeable thing is how fast things freeze.
The inside of a face mask takes a few seconds to freeze and is ‘extremely uncomfortable,’ Mr Liautaud explained, while your eyes can become glued shut and boiling water takes just a couple of minutes to freeze in temperatures of -20°C.
‘Everything is really hard but there’s no point in focusing on the negatives. We are in an incredible place and are lucky to be here,’ he said.
The expedition has three scientific research programmes, one of which is to study the deposition rate of Tritium, a radioactive isotope of Hydrogen, across Antarctica.
The data collected will be used to better understand the global water cycle, which is important to unravelling the mysteries of climate change.
Mr Liautaud and Mr Stoup’s data will show the variability of isotope composition in precipitation across Antarctica and the pair’s samples come from ice that has not yet been researched.
The ‘Coldfacts 3000BX’ mobile weather station they have deployed will collect data that can be compared to established stations nearby.