MOSCOW, November 17. /TASS/. The Russian crew of the International Space Station will be increased from two to three no sooner than the spring of 2018 after a multifunctional laboratory module Nauka (Science) enters service, Roscosmos Executive Director for Manned Space Programs Sergei Krikalyov told TASS on Thursday.

Two of four Soyuz crews to fly to ISS in 2017 will be smaller than usual

It was earlier reported that the number of Russian cosmonauts working aboard the world’s sole orbiter would be reduced from three to two starting from the spring of 2017.

"The State Commission has approved the switchover to two persons before the multifunctional laboratory module enters service," he said.

The module Nauka is planned to be launched in December 2017, he added.

"After its launch, some more time will be needed for its integration into the Russian segment of the International Space Station. As soon as the multifunctional laboratory module is docked to the space station and its integration begins, a large number of outer space walks will be required. By that time, we plan to increase the Russian space crew to three members again. This will approximately take place in March 2018," Krikalyov said.