One aspect of running for political office after being an astronaut is the space jokes. I admit it: I'm fond of them. "Marc Garneau: soft on gravity." "Marc Garneau: not down to Earth." "Marc Garneau: He didn't come back from space for you." (Rest assured, I did.) As I prepared to launch my campaign for the Liberal leadership, people repeatedly asked why, having been fortunate enough to enjoy a career that's taken me around the planet more than a few times, I'd want to risk my reputation on something the media has already written off as a win for someone else? This isn't rocket science.