05/16/2013 12:09 EDT | Updated 07/16/2013 05:12 EDT

Astronaut Chris Hadfield savours fresh air of Earth

Canadian astronaut Chris Hadfield says his first "true sense of being home" after crashing back to Earth Monday night came from looking through the window of the Soyuz spacecraft as it lay toppled on its side on the steppes of Kazakhstan and seeing "dirt and grass where space had been moments before."

Shortly afterward, a rescue crew opened the hatch of the spacecraft and let the fresh air of Earth waft in over the charred scent of the Soyuz spacecraft, still hot from its plunge through the atmosphere.

"It smelled of just wind in the grass … the smell of spring," Hadfield, 53, recalled Thursday at his first news conference since returning from the International Space Station after five months in space.

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Hadfield spent almost an hour Thursday answering questions from the media about his lengthy stay in orbit, including two months as the first Canadian commander of the space station; his experience of returning to Earth; and what his plans are now.

Speaking via webcast from Houston, where he is undergoing rehabilitation and debriefings, Hadfield's made it clear that things haven't been easy since his literal crash back to Earth, thanks largely to the difficulty of getting his body used to gravity again after five months of weightlessness.

"Right after I landed, I could feel the weight of my lips and tongue and had to change how I was talking," he recalled. "I didn't realize I had learned to talk with a weightless tongue."

Yesterday, when he lay down on a mat to do floor exercises, he said, "it felt like two people were laying on top of me. It felt like someone was squeezing me down into the floor."

After holding his head up for the first time in five months, his neck and back are sore.

"Also, my body has not really remembered very well how to get blood back up to my head," he said, forcing him to wear a special g-suit to squeeze the blood back up to his brain.

After months of floating, his feet have lost their calluses "so I was walking around like I was walking on hot coals yesterday."

But, he said, his body is gradually adapting, and "it's getting better measurably, by the hour."

While in space, Hadfield garnered international attention through a clever social media campaign that included performing a song with children around the world, releasing a cover of David Bowie's Space Oddity complete with footage of him on the station, and taking part in several live chats with students — all while zipping around in zero gravity above the Earth.

He also posted on Twitter dozens of pictures of the station and various locations around the world, something that is likely to continue while he undergoes an intensive round of rehab at NASA's Johnson Space Center.

He wasn't the first astronaut to use Twitter, but he was arguably the most successful, growing his number of followers from about 20,000 to almost one million.

When asked about why reaching out to so many people via Twitter was important to him, Hadfield responded that he wanted to share the space experience with the people who pay for it via their tax dollars and who benefit from it in form of new technologies and inspiration.

"It's just too good an experience to keep to yourself," he said, "and the more people that see and understand, the more benefits of space exploration will roll back into daily life for all of us."

Hadfield said he hasn't decided yet what he will do now that he's back on Earth, although he is scheduled to take part in Canada Day festivities in Ottawa on July 1 and to be the grand marshal of the Calgary Stampede July 5-14.

"For now, that's enough," he said in French. "I have full days. For me, it's hard just to walk. I'm not ready to run."