A Russian space craft delivered three new crew members to the International Space Station, bringing its crew size back up to six.

NASA video shared on the International Space Station's Twitter page show Russian cosmonauts Oleg Skripochka and Alexey Ovchinin entering the space station along with astronaut Jeff Williams, a grandfather who became the first three-time, long-term resident of the station.

"The Soyuz hatches opened and [Williams] with 2 fellow crew members floated into their new home on orbit," they wrote.

The three men blasted off from Baikonur space center in Kazakhstan aboard the Russian space craft Soyuz-TMA-20M. They orbited the earth four times before docking at the space station.

Now aboard the space station, Skripochka, Ovchinin and Williams will join Expedition 47 crew members Tim Kopra, Tim Peake and Yuri Malenchenko as they conduct more than 250 experiments over five months.

During this time Williams will break Scott Kelly's United States record for cumulative days in space by reaching 534.

The crew will also be the first to receive and test the Bigelow Expandable Activity Module, an experimental expandable habitat. Members of Expedition 47 will not live in the habitat, but will periodically enter and evaluate it to see if it can support astronauts on future missions.