London - British astronaut Tim Peake on Friday said he will be taking part in the London marathon - harnessed to a running machine 400km above Earth on the International Space Station.
"As soon as I got assigned to my mission to the International Space Station, I thought wouldn’t it be great to run," said Peake, a former helicopter pilot who will be running for the Prince's Trust charity.
"The London Marathon is a worldwide event. Let's take it out of this world," the 43-year-old said.
Peake is due to take off on December 15 from the Baikonur cosmodrome in Kazakhstan on board a Soyuz rocket for a six-month mission to the ISS.
"Major Tim" - his actual rank - will be only the second Briton in space after Helen Sharman in 1991.
Regular physical exercise is essential in space to fight the effects of a microgravity on muscles.
Peake said he would run on April 24 - the day of the marathon, which has around 37 000 participants.
Thanks to a screen with a virtual reality avatar placed in front of him he will feel like he is there.
"I'll be running it with the iPad and watching myself running through the streets of London whilst orbiting the Earth at 400km above the surface and going 27 000km/h," Peake was quoted as saying in a statement released by the Prince's Trust.
He said the trickiest aspect would be the harness.
"In microgravity I would float if I didn’t strap myself down to the treadmill so I have to wear a harness system that’s a bit similar to a rucksack. It has a waistbelt and shoulder straps," he said.
Peake ran the London marathon in 1999 in 3 hours 18 minutes and 50 seconds.
This time around he recognises he will not be setting "any personal bests" but is still planning to complete it in 3 hours and 30 minutes to 4 hours.