Three new crew members representing the United States, Russia and Japan are on their way to the International Space Station after launching from the Baikonur Cosmodrome in Kazakhstan at 2:21 a.m. EST on Sunday.

The Soyuz spacecraft carrying NASA’s Scott Tingle, Anton Shkaplerov of the Russian space agency Roscosmos, and Norishige Kanai of the Japan Aerospace Exploration Agency is scheduled to arrive to the space station’s Rassvet module at 3:43 a.m. Tuesday, Dec. 19.

The arrival of Tingle, Shkaplerov and Kanai will restore the station’s crew complement to six. They will join Expedition 54 Commander Alexander Misurkin of Roscosmos and his crewmates, Mark Vande Hei and Joe Acaba of NASA. The crew members will spend more than four months conducting approximately 250 science investigations in fields such as biology, Earth science, human research, physical sciences and technology development.

Vande Hei, Acaba and Misurkin are scheduled to remain aboard the station until February 2018, and Tingle, Shkaplerov and Kanai are scheduled to return to Earth in April.

This crew continues the long-term increase in crew size on the U.S. segment from three to four, allowing NASA to maximize time dedicated to research on the space station. Highlights of upcoming investigations include demonstrating the benefits of manufacturing fiber optic filaments in a microgravity environment, a new study looking at structures that are vital to the design of advanced optical materials and electronic devices and examining a drug compound and drug delivery systemdesigned to combat muscular breakdown in space or during other prolonged periods of disuse, such as extended bed rest on Earth.