The International Space Station's crew now has six members for the first time in its 10-year history, after a Russian capsule carrying three astronauts docked at the orbiting outpost on Friday.
The Soyuz TMA-15 capsule carrying the astronauts docked with the ISS at 13:34 BST (08:34 EST).
Roman Romanenko, from Russia, Frank De Winne, from Belgium, and Canadian Robert Thirsk, blasted off from Baikonur Cosmodrome on Wednesday morning.
The current crew, consisting of Russian cosmonaut Gennady Padalka, Nasa astronaut Michael Barratt and Japanese astronaut Koichi Wakata, will not come straight home.
All six will stay aboard the station until a new crew rotation in October.
There is so much potential in this beginning, in this historic milestone, Steve MacLean, president of the Canadian Space Agency and a former astronaut, said at the Russian control center outside Moscow. It represents what we will be able to achieve with future programs ... and what we as a combined series of countries can do for the future exploration of space.
In just a few weeks, shuttle Endeavour and its crew of seven will arrive a record 13 people will be at the space station, but that will be only temporary.
After four months, De Winne will take over as commander of the ISS from Padalka.