Canadian astronaut Chris Hadfield, the most popular man in space, is coming back to Earth today after a stint aboard the International Space Station that has reignited interest in space worldwide.

It has been an eventful final weekend in space for Hadfield. An unexpected ammonia leak prompted a spacewalk on Saturday, in which NASA astronauts Chris Cassidy and Tom Marshburn ventured outside the ISS to investigate the problem. They replaced a pump controller box on the station’s backbone, which seemed to resolve the issue for now. On Sunday, Hadfield transferred command of the ISS over to Russian cosmonaut Pavel Vinogradov. And he still found time to release a music video:

The video quickly went viral, which is par for the course for Hadfield, who might be the most recognizable astronaut in recent memory, thanks to his prolific updates from space on social media. While Major Tom, the astronaut in David Bowie's song, loses contact with the ground and slips away from humanity in space, Hadfield has had almost the exact opposite experience. He has a direct line to millions and shares the beauty of space with the humans down below.

Astronauts used to have to relay Internet communications through ground-based mission control, which didn’t make for easy tweeting. But in 2010, the ISS finally got Internet installed; it uses a high-speed antenna to connect with a ground-based computer that’s hooked up to the Web.

Other ISS astronauts were posting about their missions long before Hadfield came aboard, but the Canadian’s gregarious stream of tweets and posts has garnered an impressive worldwide following. On a given day, Hadfield might post a few breathtaking pictures of Earth, or a self-portrait taken while squeezing into a pressure suit (“like being born in reverse,” he quipped) or a video about how hard it is to wring out a washcloth in zero-gravity.

After garnering a following of hundreds of thousands of people in a few short months, Hadfield and two others will leave the ISS in a Soyuz capsule scheduled to touch down in Kazakhstan on Monday night. The 53-year-old might need a few days or weeks to readjust to gravity and to recuperate -- spending a long time in space can cause muscle wasting and other health effects. But he plans to keep carrying the fire here on Earth.

"It's going to be so much greater when he comes home and people can interact with him face to face now that they know what he's achieved and what it's possible to achieve,” Hadfield’s son, Evan, told CBC News on Monday.

Many people -- ahem, Americans -- might not have known that Canada even has a space agency. But Hadfield has propelled the CSA into the limelight at a time when the agency’s future is still uncertain.

But of course, there’s only so much one man can do.

"As much as he's captured the attention of Canada and the media for this, unfortunately I don't think that there is anywhere else for this to go,” Canadian Space Society Vice President Marc Fricker told the CBC. "Unfortunately, the space agency is dwindling. Its budgets are being cut. Its people are leaving as a mass exodus in some instances.”

Space science in Canada may need a charismatic defender in the near future. The Canadian government has been roundly criticized for the perceived muzzling of researchers -- putting loads of red tape in the way before a scientist can talk about their latest climate change findings with a reporter.

And now, Canada’s National Research Council is focusing on funding more business-driven scientific projects. Many scientists balk when governments start tying research funding to short-term marketability and profitability, fearing that such moves will throttle basic research, whose seeds may take longer to germinate.

“If proposed and immediate economic benefits are the prime factors in choosing what science to fund, then the freedom of this human endeavor will be critically curtailed,” astronomer Phil Plait wrote for Slate on Monday. “It’s draining the passion and heart out of one of the best things we humans do.”

Hadfield’s quite familiar with basic science. He performed more than 130 scientific experiments during his time on the ISS. He wore a sensor on his head to monitor internal temperature changes as part of an investigation into how astronauts adjust to the disrupted circadian rhythms of working in orbit. He drew his own blood to help researchers understand how space travel may contribute to stiff arteries.

“The guy that you see on the Twitter feed and talking to all the school kids -- he’s a really personable guy,” University of Waterloo researcher Richard Hughson told the Toronto Star. “But he recognizes underneath ... that it’s a very serious job.”