The Russian space agency said in a statement that the seal between the capsule and the space station was being checked, and the transfer hatch was expected to be opened between 11:55 and 12:25 Moscow time (07:55 and 08:25 GMT).
The Soyuz-FG rocket blasted off on Monday in Russia's first manned mission in more than five months after the workhorse rockets were temporarily grounded following the failed launch of an unmanned Progress supply ship in August.
The capsule was carrying American Dan Burbank and Russians Anton Shkaplerov and Anatoly Ivanishin, who are joining the three crew on board the ISS.The current ISS crew of American Mike Fossum, Japan's Satoshi Furukawa and Russia's Sergei Volkov will return to Earth on November 22 and a new crew will head up from Baikonur on December 21.
The crash of the Progress in Siberia eroded faith in Russia's status as a space superpower just as it had taken the responsibility for being the sole nation capable of taking humans to the ISS after the retirement of the US shuttle in July.
The Soyuz-U rocket that failed to take the Progress to orbit is closely related to the Soyuz-FG that is used for manned launches, prompting the temporary grounding of the entire arsenal of the Soyuz rockets after the accident.
Russian scientists are also bracing for the likely loss of the Phobos-Grunt probe for Mars which was launched on November 9 but has failed to head out of Earth's orbit on its course to the red planet.
The recent problems were a major disappointment for Russia in the year marking half a century since Yuri Gagarin made man's first voyage into space from the same historic cosmodrome.