Britain's Tim Peake has hung up his spacesuit, stepping down from Europe's astronaut corps to become an ambassador for space activities, the European Space Agency said on Friday.
Peake, who became the first British astronaut to visit the International Space Station in 2015, said it had been an "incredibly exciting and rewarding" 13 years.
"Being an ESA astronaut has been the most extraordinary experience," Peake, 50, said in a statement.
"By assuming the role of an ambassador for human spaceflight, I shall continue to support ESA and the UK Space Agency, with a focus on educational outreach, and I look forward to the many exciting opportunities ahead."
The ESA said that Peake had been on an unpaid leave of absence since October 2019, and had retired from active astronaut duties from the start of this year.
The UK's second astronaut after Helen Sharman, Peake was the first Briton to complete a spacewalk outside the ISS.
During a six-month stint on board the ISS from 2015-2016, he contributed to scientific missions, helped dock two spacecraft -- and even ran the London marathon on a treadmill.
ESA director-general Josef Aschbacher thanked Peake for his service.
"Tim has been a role model for kids, aspiring youngsters and young professionals alike, inspiring millions of them and at the same time being an excellent ambassador for the whole of ESA, its values and its ambition," Aschbacher said.
Paul Bate, head of the UK Space Agency, also hailed the astronaut.
"We wish Tim all the best and look forward to supporting him in his next adventure, knowing that the UK's role in human space exploration is in the safe hands," Bate said.
Britain's Rosemary Coogan joined the ESA's astronaut corps in November, while British doctor and Paralympian John McFall was named the first-ever astronaut recruit with a disability.
While the UK has left the European Union, it remains one of the ESA's 22 member states.