Travelling to space is a dream of many school children, especially those who go to a school named after Canadian astronaut Chris Hadfield.

Many of the kids attending that school could be part of the generation that makes it to Mars, a goal long desired by astronauts.

"We want to go to Mars because actually we can set up bases and colonies there in the future," Canadian astronaut Bob Thirsk told the students.

But, the journey to Mars would talk months, and it would present a special challenge to those on the flight -- having enough food to last the entire trip -- and back.

"Food is the main driving variable in the equation for taking humans off this planet for long periods of time," Mike Dixon, Chair of the Department of Environmental Biology at the University of Guelph told CTV Newsnet.

So, students across the country are taking part in an experiment to find a solution to that problem.

One possible answer is to grow it as you go, and students at Chris Hadfield Public School in Milton, Ontario are trying to figure out if that's possible by taking part in a program called "Tomatosphere."

As part of the project, Bob Thirsk has brought tomato seeds from the International Space Station to the students. The seeds had been on the station for 19 months, and were packaged so they wouldn't spill and float around the micro-gravity environment.

They are some of the 400,000 seeds that were brought back to earth aboard the Space Shuttle Discovery on Aug. 9.

"They were exposed to the kind of radiation environment that you would have on the International Space Station, outside of earth's environment, and weightlessness for that time, acceleration of launch, and deceleration of returning to earth," Mike Dixon said.

"What we're going to do is determine whether or not seeds that have spent 19 months in the space environment can potentially form a future crop for astronauts of the future," said Thirsk.

Each class in the school will get seeds to plant. They'll be asked to nurture, monitor, and report on what they found.

The hope is that the plants will grow to be perfectly normal despite being exposed to the environmental conditions of the space station.

"We have to say if they are growing good or don't look good, if they're healthy or not healthy, things like that," said student Ania Maynard.

For the 2005-2006 school year, 167,000 students in more than 5,200 classrooms across the country are taking part in the experiment.

Canadian astronaut Marc Garneau started the project five years ago, and this is the final year for it. Since it started more than 387,000 students have taken part in the program.

"We're very interested in knowing about how plants germinate when they've been exposed to different conditions," Garneau said from space in 2000.

"Tomatoes are really high on the list of what we call candidate crops to take off this planet. For all kinds of obvious reasons, they preserve well, you can turn them into all kinds of different products," said Dixon.

But, tomatoes aren't the only plants being tested for use in space. Many foods that would be seen on a vegetarian dinner plate on earth are candidates for a space menu.

"Take a normal vegetarian menu and work backwards, wheat for the flour, tofu used from soy beans, greens, peas, carrots you name it," said Dixon. "Nutritional, and aesthetically pleasing, because the psychology of space travel is not to be missed either."

Researchers estimate that it would take about 75 square metres of plant growing area per crew member to create a reliable and indefinite supply of food. But, that number has to be brought down to between 20 and 25 square metres before it is economically feasible to get to Mars.

"If Canada is to have a knowledge based economy in the future, we need to start today with science education in the elementary schools," said Bob Thirsk.

The project already seems to be getting students excited about science.

"I've never really been into science but now that I get to meet these people I guess I am," student Alissa Partington told CTV News.