British astronaut Tim Peake kicked-off this year's London Marathon with a special countdown from space as more than 40,000 people take on the famous route.
The prerecorded message was shown on big screens as runners began the 26-mile race across London.
Major Peake sent the message from the International Space Station, where he is currently in orbit above the Earth.
The 44-year-old is also taking part in the same route from space.
The astronaut will be strapped filming to a treadmill while watching the streets of London pass under his feet in real time on an iPad.
This isn't the first time he's taken part in the London Marathon as he took home a time of three hours, 19 minutes and 50 seconds in 1999.
He is aiming to cross the virtual finish line after around four to four-and-a-half hours of running just as thousands of club runners and charity fund-raisers make their way towards The Mall in the heart of central London.