Canadian astronaut Chris Hadfield has announced his retirement after a five-month mission to space that captivated the world with his Twitter microblog.
"It has been an incredible adventure," Hadfield, 53, said of his 35 years of service as a cold war fighter pilot and astronaut with the Canadian Space Agency.
Describing his recent mission to the International Space Station as "a kind of pinnacle of my entire career ... since I was a little dreaming kid of nine years old thinking of flying in space", he said it was time for him to do something else.
"In about a month I'll be retiring from the Canadian Space Agency and just pursuing private interests," Hadfield told a press conference, "and getting my feet planted on the soil and seeing where the future takes me."
Hadfield returned to earth last month with American astronaut Tom Marshburn and Russian cosmonaut Roman Romanenko.
From space, Hadfield captured the public imagination with regular updates on Twitter that gave an unprecedented insight into daily life in space and access to spectacular images taken from the ISS.
Tweeting under the name Cmdr-Hadfield, the astronaut posted spectacular pictures of the earth and also insights on the mundane aspects of eating and washing in space.
He and his team held the first live news conference from space, recorded the first music video in space - a cover of David Bowie's classic Space Oddity - and conducted a record number of scientific experiments on the ISS.
Using the power of social networks more effectively than anyone in the history of manned space flight, Hadfield has arguably become the world's most prominent astronaut since the days of Neil Armstrong and Buzz Aldrin.
He inspired the public at a time when some scientists question the need for manned space flight to the ISS amid constant budget pressures.
Hadfield said he is still readapting to gravity since landing - his heart shrank and he has lost skeletal mass. But he said he should be "almost back to normal" by September.
He will retire on July 3.