A Soyuz spacecraft carrying three astronauts — one each from the United States, Russia and France — lifted off from the Baikonur Cosmodrome in Kazakhstan at 3:20 p.m. EST Thursday. The astronauts will join the three Expedition 50 crew members already on board the International Space Station (ISS) when the spacecraft docks with it Saturday evening.

“The Expedition 50 crew members will spend over four months conducting more than 250 science investigations in fields such as biology, Earth science, human research, physical sciences and technology development,” NASA said in a statement. “Upcoming research includes how lighting impacts the overall health and well-being of crew members, and how microgravity affects tissue regeneration in humans and the genetic properties of space-grown plants.”

16-108d Three crew members representing the United States, Russia and France are on their way to the International Space Station after launching from the Baikonur Cosmodrome in Kazakhstan at 3:20 p.m. EST Nov. 17, 2016 (2:20 a.m. Nov. 18, Baikonur time). Photo: NASA/Bill Ingalls

Thursday’s launch is a historic one for both France and the U.S. While Thomas Pesquet from the European Space Agency will become the first French member of an ISS expedition, American astronaut Peggy Whitson is now the oldest woman to fly in space.

“The most important thing about the station is the friendships and the work we accomplish there,” Whitson, 56, said during a press conference held before the launch in Kazakhstan.

By the time the mission is over, Whitson, who will take command of the ISS in February, would also become the first woman to command the space station twice — the first being in 2007. In addition, she would also have set a new record for the most hours spent in space by a U.S. astronaut, breaking the current record of 534 days set in September by Jeff Williams.

Whitson, Pesquet and the Russian cosmonaut Oleg Novitskiy will remain on board the ISS until next spring. The crew members already aboard the station — Expedition 50 Commander Shane Kimbrough of NASA and cosmonauts Sergey Ryzhikov and Andrey Borisenko — are scheduled to return in late February.

Humans have been living continuously aboard the ISS for more than 15 years, and so far, over 200 people from 18 countries have visited it. Although the arrival of Whitson, Novitskiy and Pesquet returns the number of crew on the ISS to six, this may be one of the last missions where this happens, as Russia has announced plans to cut crew size to two beginning next March.