Canadian astronaut Chris Hadfield, the former commander of the International Space Station who just returned to Earth in May, announced his resignation from the Canadian Space Agency today, concluding a 35-year-long career. Hadfield, 53, said he was stepping down effective July 3rd primarily for personal reasons: he wants to move back to Canada from his current home in Houston, Texas, where he's lived since the 1980s and trained with US NASA astronauts. "[I'll be] making good on a promise I made my wife nearly 30 years ago — that yes, eventually, we would be moving back to Canada," Hadfield said in a press event at CSA headquarters outside Montreal, as reported by CBC.

"I will continue to reinforce the importance of space exploration."

The official word from the CSA is that Hadfield is resigning to "pursue new professional challenges," but it's unclear for now just what those might be. Hadfield, the first Canadian commander of the space station, became an international celebrity thanks to his active social media presence from space — including a killer David Bowie cover. He's a national hero in Canada and many have speculated he might run for office in the country, but he's been downplaying that possibility so far, telling The Canadian Press in May that "right now, I have no [political] aspirations at all." Hadfield said today that he still plans to work with the CSA to spur public interest in space travel. "I will continue to reinforce the importance of space exploration through public speaking and will continue to visit Canadian schools through the CSA," he said in a statement.

Update: Hadfield took to Twitter on Monday to thank his fans and followers.