Italian astronaut Paolo Nespoli, American astronaut Randy Bresnik, and Russian cosmonaut Sergey Ryazansky are the newest astronauts to join the ISS team.

Their Soyuz MS spacecraft managed to rendezvous with the space station on time six hours after the launch, according to the Russian space agency Roscosmos.

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The European Space Agency shared a video of the launch online.

The three crew members are due to spend more than four months aboard the ISS before returning to Earth in December.

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The group will bring the ISS up to its full crew of six and will work on various experiments in biology, biotechnology, physical science and Earth science, according to NASA, which shared a video of the crew as they reached orbit.

Short-staffed and overqualified

In April, Russia decided to reduce the crew of its side of the ISS to just two. In response, the US boosted its crew to four.

Sixty-year-old Italian Nespoli is the most experienced of the new crew, having already spent 174 days in space. He traveled to space once in 2007 and once in 2010.

He shared his enthusiasm in a tweet shortly before the launch.

The future of space exploration

NASA says it will start sending astronauts up to the station using ships developed by SpaceX and Boeing by the end of next year. Both spaceships have room for a fourth person, allowing them to boost the station's overall crew size to seven - once Russia decides to return to full staffing.

NASA uses the ISS to prepare for human missions to the moon and Mars and to stimulate commercial space transportation, pharmaceutical research, manufacturing and other businesses.

A total of 15 nations are part of the ISS project - the only manned space station orbiting the earth.

aw/bk (Reuters, AP, AFP)