Main and backup crews for the next mission to the International Space Station began final tests at a space training center near Moscow Thursday.

A Russian official said the two-day exams "must confirm the readiness" of those aboard the Soyuz TMA-17.

The Russian spacecraft is to lift off from the Balkonur space center in Kazakhstan on Dec. 31, RIA Novosti reported.

The main crew includes Russian cosmonaut Oleg Kotov, U.S. astronaut Timothy Creamer and Japanese astronaut Soichi Noguchi.

The backup crew comprises Russian cosmonaut Anton Shkaplerov, U.S. astronaut Douglas H. Wheelock and Japanese astronaut Satoshi Furukawa.