The next Canadian to travel to space is biding his time under quarantine in Kazakhstan, standing by in case something goes wrong to replace an astronaut set to blast off next month, before his own maiden space mission in December.

David Saint-Jacques is serving as a backup to European Space Agency astronaut Alexander Gerst, a member of a three-person team gearing to visit the International Space Station (ISS) on June 6. Saint-Jacques and his crew are living in quarantine to avoid germs ahead of the launch.

The Quebec City-native is a medical doctor as well as a PhD in astrophysics. He holds a commercial pilot licence with multi-engine and instrument ratings, and speaks French, English, Spanish, Japanese and basic Russian.

In an interview with near the Baikonur Cosmodrome, Saint-Jacques spoke about how he felt the first time he put on his custom-fit space suit, how his six-month mission will help doctors connect with patients in Canada’s most remote communities, and the childhood toy he plans to bring with him into orbit on Dec. 20. What would have happen in order for you to step in and join the June 6 mission?

Saint-Jacques: Typically a medical problem. That would be the most common scenario. At the last minute, it has never really happened. It has happened a couple of times in history, a few months before, but at the last minute we are very, very careful, as you can imagine.

Something as benign as just a common cold would be bad news for someone launching into orbit. Having to do a lot of pressurization of their space suit, and already being in zero gravity, because of fluid shift, you feel really congested anyway to start off. Not to mention if you have gastroenteritis, or something like that. What is life like under quarantine?

Saint-Jacques: I feel like I’m sitting on my hands. We're just doing everyday reviews of procedures and practicing manual flying. Then of course we go to the gym. We get checked out by the doctor every day. How does it feel to be counting down the days until you travel to space in December?

Saint-Jacques: It has been years of training, a lot of theory and training in simulators. It kind of all felt like this was maybe space camp, not the real thing. Now we are getting near the real thing. A few days ago, I tried on my real space suit. Not a training space suit, a real one that is custom sized to me. We fitted it inside the real rocket in the real capsule. Suddenly everything has a feel of reality to it. There is a lot of anticipation in the air. This will be my first mission to space, knock on wood, if all goes well. What are you and your crew hoping to achieve on board the ISS?

The theme of a lot of the Canadian Space Agency sponsored research is remote care medicine with applications here on earth for the remote people that live far away from big city centres. We need remote care and medical technology. Space is the best to develop those technologies. Chris Hadfield has become famous for strumming an acoustic guitar while in space, are you bringing any unique personal items?

We don't have a lot of luggage space. It's about the size of a small backpack you can take for six months.

I know for sure I'm going to pack my old Rubik's cube that my Dad gave me when I was a child. And I'm going to bring a couple of books, probably electronic versions. I'm a big reader. I'll certainly bring some jewels from the family to fly them in orbit with me. Our wedding rings, for example. I've asked friends and family members to provide me with small objects of significance to them that we can fly in space.

This interview has been edited for length and clarity