Canadian astronauts are preparing for their next space mission by undergoing survival training in the forests of Russia.

The wilderness portion of the survival course is as realistic as it gets. Astronauts are stranded in Star City, just outside Moscow, to simulate conditions found in the middle of the Siberian forest where a Soyuz rocket crashed more than four decades ago.

The astronauts' mission is to stay alive only with what they find onboard — seats, space blankets, parachutes.

"To stay warm is the biggest deal here of course. It is below –20 C at night so you got to maintain a fire, you got to find all the wood you need and you got to stay warm," David Saint-Jacques, an astronaut with the Canadian Space Agency, told CBC News.

"They told us in the spirit of this training: 'We will find you. Your job is to survive until we find you.' "

Soyuz space capsule seen in the forest Tuesday during a complex training on emergency landing at a marshy wooded site in winter, with members of an expedition to the International Space Station. (Mikhail Metzel/Associated Press)

Though the experience might seem like an unlikely scenario, it has happened before.

After Russian cosmonaut Alexey Leonov successfully performed the first spacewalk in history in March 1965, his spacecraft veered off course on its way back to Earth and crashed in Siberia.

Stranded in the forest, surrounded by wolves and bears, Leonov and his crew had to spend two nights in the elements before being rescued.

'Exciting to come here and train'

Since then, survival training is mandatory for Russian cosmonauts and for anyone likely to fly on a Soyuz rocket.

"Right now, the only way to get to the [International Space Station] is on the Russian Soyuz rocket," said Maj. Jeremy Hansen, an astronaut with the Canadian Space Agency.

"So it is exciting to come here and train, both from the perspective that I may one day fly on Soyuz but also just the opportunity to learn the culture here and to learn another space."

During training sessions, Canadian astronauts face another challenge.

"It's all in Russian. With my little Russian, beginners Russian, they speak slowly to me, I ask to repeat sometimes. But you know, we get some understanding going. And it's been already more than 24 hours together, and so far, I think we've understood each other," said Saint-Jacques.

Following two nights in the cold and after building two shelters and carrying a wounded crewmember, help finally arrived.

"It's yet another practice at teamwork in intense circumstances. And that's always useful in this job," said Saint-Jacques.

Hansen and Saint-Jacques will next spend time on a Soyuz simulator for a couple more days.

So far, Chris Hadfield is the only Canadian astronaut who has been assigned a space mission.

He is scheduled to take off in November onboard a Soyuz rocket and spend six months aboard the International Space Station.

Both Saint-Jacques and Hansen are based in Houston, Texas, and haven't so far been assigned a mission in orbit.

With files from Jean-François Bélanger