A British adventurer was close to becoming the second person to traverse Antarctica completely unassisted just a few days after an American became the first to conquer the feat, which was previously said to be impossible.

Louis Rudd's expedition blog on Thursday showed that the 49-year-old has only has about 50 miles (80 kilometers) left on the journey across the continent and is expected to finish Saturday.

If Rudd — a Hereford, England, resident and captain in the British Army — completes the journey, he'll become the second man to do so after Colin O'Brady of Portland, Oregon, became the first on Wednesday.

The more than 900-mile (1448-kilometer) trek took O'Brady 54 days. O'Brady and Rudd were competing to become the first to travel across Antarctica without getting new supplies or help from the wind.

O'Brady won after he covered the last roughly 80 miles (129 kilometers) in one big, impromptu final push to the finish line that took well over an entire day.

"While the last 32 hours were some of the most challenging hours of my life, they have quite honestly been some of the best moments I have ever experienced," O'Brady posted on Instagram, where he has been documenting the arduous journey.

Rudd congratulated O'Brady on his blog late Wednesday.

"I've just heard that the American Colin's finished," he wrote. "Fantastic, well done to him. He'd pushed really hard all the way across and done extremely well, so congratulations to him."

Rudd wrote that he never felt like he was in a race and that "it's always been about completing the journey."

"That'll be incredible," he wrote.

It's been an emotional trek for Rudd, who decided to do the solo in honor of his close friend and fellow British explorer Henry Worsley, who died near the end of his attempt at an unassisted solo trek across Antarctica in 2016.

Though others have traversed Antarctica, they either had assistance with reinforced supplies or kites that helped propel them forward.

O'Brady plans to stay on Antarctica until Rudd finishes his trek, said O'Brady's wife, Jenna Besaw.

"It's a small club," she joked. "His intention is to wait for Louis and have kind of a celebratory moment with the only other person on the planet to have accomplished this same thing."

O'Brady finished his trek as friends, family and fans tracked the endurance athlete's progress in real time online.

"I did it!" a tearful O'Brady said on a call to his family gathered in Portland for the holidays, according to Besaw.

O'Brady, who had been told he may never walk again after an accident burned his legs in 2008, described in detail the ups and downs along the way since he began his Antarctic trek on Nov. 3.

In the beginning, he had to haul 375 pounds (170 kilograms) of gear uphill and over sastrugi, wave-like ridges created by wind. By the end of the journey, his gear weighed roughly 140 pounds (64 kilograms).

On Nov. 18, he wrote that he awoke to find his sled completely buried from an all-night blasting of wind and snow. That day he battled a 30 mph (48 kph) headwind for eight hours as he trudged along.

"I wanted so badly to quit today as I was feeling exhausted and alone, but remembering all of the positivity that so many people have been sending, I took a deep breath and focused on maintaining forward progress one step at a time and managed to finish a full day," he wrote.

On Day 37, Dec. 9, O'Brady posted about how much he's changed, along with a selfie in which he looks almost in pain, snow gathered around his furry hat.

"I'm no longer the same person I was when I left on the journey, can you see it in my face?" he wrote. "I've suffered, been deathly afraid, cold and alone. I've laughed and danced, cried tears of joy and been awestruck with love and inspiration."

Though O'Brady had initially thought he'd want a cheeseburger at the end of his nearly impossible journey, Besaw said her husband has been fantasizing about fresh fish and salad because he has mostly been eating freeze-dried foods.

As for what's next for O'Brady, who also has summited Mount Everest, Besaw said she's not entirely sure.

"We are just so in the moment celebrating this right now," she said. "Then we'll see what's next on the horizon."

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Follow Amanda Lee Myers on Twitter at https://twitter.com/AmandaLeeAP