He's onboard a Soyuz rocket, which blasted off from its launch site in Kazakhstan at exactly 11-03 and ten seconds.
On arrival at the space station, he will be greeted by the first ever doll to visit space - her name is Lottie and she was created by Donegal business, Arklu.
Lottie was designed by six-year-old Abigail from Canada who is a big fan of astronomy. She submitted the product idea to the company who picked the design. She went to space last week.
Ian Harkin is Managing Director and founder of Arklu earlier explained more: