In an interview Thursday, Hadfield said being in space for six months will be far different from his two previous excursions, which were much shorter.
"It's the difference between a quick visit somewhere — a drive past — and moving somewhere," Hadfield said.
"You have to think about how many tooth brushes to bring, how you're going to set up life, how you're going to celebrate all the anniversaries."
Hadfield, 53, is due to blast off Dec. 19 aboard a Russian spacecraft with an American and Russian to become the first Canadian to take command of the International Space Station.
With only a few others — Canada's Bob Thirsk among them — having spent so long in space in one stretch, Hadfield said he has concerns about staying physically and mentally healthy.
There is also still much to be learned about the experience of spending extended periods in confined, weightless conditions, he said.
"It's not just new for me, it's still new in the human experience," Hadfield said.
"The stuff we're figuring out in our six months on space station ... is writing the book on how people are going to leave Earth."
In his first mission in 1995, the first Canadian to walk in space spent just over a week helping build the Russian station "Mir." In his second in 2001, he spent almost two weeks helping build the International Space Station.
Hadfield called weightlessness "really fun and easy" but noted the deleterious effects it has. Those effects include muscle atrophy, loss of bone density, and having the balance system shut down.
"All of those things that build you a strong body get lazy," he said. "You don't even have to hold up your head."
As a result, astronauts need to use resistance machines to exercise so they have the strength to work in a space suit during spacewalks or manage when they return to gravity.
As commander of the International Space Station, Hadfield said he will be responsible for everything — from the smallest experiment to "getting hit by a meteorite" to flying the vehicle.
His comments came during the public introduction of "Next-Generation Canadarm" prototypes, sophisticated robotic devices being built for the Canadian Space Agency at the MacDonald Dettwiler and Associates plant.
The robotic arms could be used to refuel satellites or service different spacecraft and telescopes.
The new arms will have comprehensive and specialized tools and possibly visual systems that will give them huge versatility and a degree of autonomy in the projects they can tackle.
"Robots aren't as good as people," said Cameron Ower, research and development director at MDA whose "Dexter" is currently aboard the space station.
"But it's starting to get to the level where the robot has to start to do the things that a human would do."
Hadfield, who used the original "Canadarm" during earlier missions, called it amazing how astronauts can use robots to lift massive structures in space, or surgeons can use them to remove cancer from someone's brain.
"When a machine is built well, it's like an extension of your body," he said. "You don't even think that you're operating a machine."