Mice won’t make part of a new expedition to the International Space Station (ISS), Russian cosmonaut Fyodor Yurchikhin said at a press conference at the Cosmonaut Training Center on Monday.

"Mice surely won’t be present there. The container weighs about 70 kg. Items that can comfortably fit into the container have been defined: wet wipes and foodstuffs. The container should be filled in specifically so that it does not interfere with the spacecraft’s controls," the cosmonaut said, adding that the list of supplies will be specified during the spacecraft’s first fit-check procedure on April 6.

As the cosmonaut explained, NASA and Russia’s State Space Corporation Roscosmos earlier held preliminary talks on the dispatch of American mice together with a manned expedition aboard a Soyuz spacecraft for a joint experiment on the world’s sole orbiter.

A Soyuz-FG carrier rocket is scheduled to blast off at 10:13 a.m. Moscow time (07:13 GMT) on April 20 to deliver a Soyuz MS-04 manned spacecraft to the International Space Station. The spacecraft is planned to dock with the Poisk module of the ISS’s Russian segment at 4:22 p.m. Moscow time (1:22 p.m. GMT) on the same day.

The new expedition is expected to last 136 days.