Astronaut Completes London Marathon From The International Space Station

About 38,000 runners competed in the London Marathon today – and one of them ran it in orbit 200 miles above Earth.

British astronaut Tim Peake completed the 26.2 mile course at the International Space Station with an estimated time of 3:35.21 , the European Space Agency tweeted.

He was also the official starter of the race in a video message played at the starting line. "I'm really excited to be able to join the runners on earth from right here on board the Space Station. Good luck to everybody running, and I hope to see you all at the finish line," Peake told his fellow competitors.

Of course, running in space poses serious challenges. Peake told reporters earlier this week that it's been difficult to get comfortable with the harness system, which he says is like running with a "clumsy rucksack on." The system keeps him from floating off the treadmill. He explains how it works:

"These chains connect to a bungee system, and that keeps me on the treadmill and gives me the weight bearing that I need on my legs to stimulate those muscles and to make sure we don't lose too much muscle mass, that we don't lose too much bone density."

As The Guardian reports, "weightlessness is not kind to astronauts. The perceived lack of gravity deconditions the body in a number of ways."

But Peake says the microgravity conditions are actually a "perfect environment" for post-race recovery:

"The moment you stop running and the moment you get off that bungee system, your muscles are in a completely relaxed state. And I do think we recover faster up here from any kind of aches or sprains."

He spoke about how inspiring the crowds and the atmosphere were when he ran the London Marathon in 1999. To give a digital sense of the atmosphere down below, Peake made use of the RunSocial app: "so I'll actually be looking at the route that I'm running, and I'll be running alongside everyone else who's running the digital version of the London Marathon."

RunSocial tweeted out moments during Peake's race, like this one where he crosses the Tower Bridge:

When Peake spoke to reporters, he hadn't yet decided on his plans for a pre-race breakfast. He was considering baked beans, sausage and eggs, but added that food in microgravity doesn't "settle very well" and that he'd need to eat well before the race.

As for tunes, Peake has been tweeting out a playlist using the hashtag #spacerocks.

Peake is the second astronaut to run a marathon from the International Space Station. Sunita Williams completed the Boston Marathon while in orbit in 2007.

Larry Williams tells our Newscast unit that in London today, Kenyans dominated:

"Defending men's champion Eliud Kipchoge completed the 26.2 mile course just 8 seconds off the world record,breaking the tape in front of Buckingham Palace in 2 hours, 3 minutes and 5 seconds.

"Kipshoge, looking fresh at the end, was 46 seconds ahead of fellow Kenyan Stanley Biwott, who won last year's New York marathon.

"In the woman's race, 31 year old Kenyan Jemima Sumgong took the marathon for the first time. Recovering from a hard tumble to the ground with around 4 miles remaining, Sumgong quickly got up rubbed her head and made up for lost time to win with 5 seconds to spare. Her time was 2 hours, 22 minutes, 58 seconds."