UK's first astronaut floats into the International Space Station

The UK's first astronaut has been welcomed aboard the International Space Station in a cramped but friendly embrace by his new colleagues.

Tim Peake was joined by NASA astronaut Tim Kopra and Roscosmos Yuri Malenchenko as the new crew members of Expedition 46.

All three men floated through the hatch about 6am (AEST time) and were greeted by Expedition 46 Commander Scott Kelly and Flight Engineers Mikhail Kornienko and Sergey Volkov of Roscosmos.

The narrow hallway proved a tricky meeting point as each crew member hugged each other and bumped their way inside the orbiting laboratory.

The new crew members will install equipment and conduct experiments to help NASA's journey to Mars during a six-month stay aboard the station.

Welcoming party Kelly and Kornienko are about nine months into a one-year stay.