Astronaut Tim Peake completed Sunday's London Marathon in 3 hours, 35 minutes and 21 seconds. However, he didn't wind through London's streets with 39,000 other runners, cheered on by hordes of observers. Instead, he ran in the tranquility of space, strapped into a harness and tethered to the treadmill aboard the International Space Station.
"Weightlessness, I think, is one of the perfect environments, because the moment you stop running, and the moment you get off that bungee system, your muscles are in a completely relaxed state," said Major Peake in a video.
The British astronaut is in month four of his six-month stint aboard the international science laboratory in orbit 250 miles above Earth.
He ran the 26.2-mile route while watching TV coverage of the race and with the help of an iPad app called RunSocial that simulated the marathon route from Shooters Hill in southeast London to Westminster. His started with a pace of 7.5 miles per hour, but 20 miles into the race sped up to nearly 9 m.p.h., as The Guardian reports.
Peake wore a harness that counteracted the effects of weightlessness by loading him with 70 percent of his Earth bodyweight; the bungee cord kept him grounded. But the system, though critical, is not perfect, as the straps of the harness, constantly shifting, cause abrasions on the skin.
"One of the biggest challenges is the harness system," said Peak, according to the BBC. "Obviously, my body weight has to be firmly attached to the treadmill by this harness, and that can rub on the shoulders and around the waist," he said.
But he persevered, finishing with a time that garnered him a Guinness World Record for the fastest marathon in orbit. Though it wasn't the first. American astronaut Sunita Williams ran the Boston Marathon from space in 2007 in 4 hours and 24 minutes. As The Guardian points out, it's impossible to compare their times because they ran with different harnesses and different loads.
The last time Peake ran a marathon was in London in 1999, reports The Guardian. He finished that race in three hours and 18 minutes.