Hadfield, astronaut Thomas Marshburn and cosmonaut Roman Romanenko have been aboard the station since December 21. They are due to return to Earth on May 13.

Among Hadfield’s first duties as commander is overseeing the packing and release of the visiting Space Exploration Technologies’ Dragon cargo capsule. The capsule, making a second resupply run for NASA, is due to depart the station on March 25.

Hadfield has taken to Twitter to share his experiences in orbit with short messages and pictures dispatched several times a day. His followers now number more than 512,000.

“My heartfelt congratulations to Commander Hadfield and his family on what is an important milestone for all Canadians,” Canada’s Industry Minister Christian Paradis said in a statement.