By 1992, as U.S. plans to establish a permanent space station grew into an international project, Garneau was seconded to NASA as a mission specialist, a full-fledged astronaut.
He moved to Houston and made a second flight in 1996, a less-burdened, less public affair.
Garneau's third and last flight was a year ago. The media attention never matched the frenzy of his first foray into space -- ironic since his contribution was key to the mission, which itself was essential to the space station's future.
He operated the Canadarm to install a 17-tonne, bus-sized scaffolding that held two solar panels to power the space station. The slow, precise task required precision in the millimetres and Garneau did it flawlessly, despite having to grapple the structure away from its centre of gravity and working without clear, direct sight, relying only on video images.
Even before the mission, he was indicating he would retire from flight duty. He is in his 50s, and another mission would have been several years down the road. He was looking for new challenges. "As you get older, your ability to think quickly and react quickly diminishes, but your ability to think deeply, I believe, improves."
In the end, Garneau, the well-travelled sailor, grew weary of the brash, gung-ho world of test pilots and of life in Houston's suburbs. "Texans think differently from Canadians. It's a subtle things. I went down when I was 43. Maybe by the time you're 43, if you're Canadian, you're Canadian for life.
"So it's nice to be back home. We have a more reserved and liberal way of looking at things. Americans, certainly in the astronauts crowd, are very, very patriotic. And, I think, consequently some times, a bit narrowly focused," he says.
"They're people who mean very well. We had wonderful friends there. But they don't look at the world in complex terms. Everything tends to be black and white. It's very much based on the American model of patriotism and love of country and love of God. It is, perhaps, not the same sort of richness and complexity I tend to feel more comfortable with, living in Canada."
Last February, the Garneaus moved back to Quebec. "It was a real shock to arrive back on the first of February. Totally different weather. We arrived smack in the middle of winter, leaving a place where winter is the only really nice time of the year."
He still gets recognized every day and knows that even when he heads to the hardware store on Saturday, he has to be properly groomed and ready to answer questions about "what it was like."
Garneau has two more children with his wife, Pamela, and one of them, his five-year-old, is learning to ice skate, so he's well on his way to "becoming a Canadian."