MOSCOW (AP) — Two Russian cosmonauts ventured out of the International Space Station Wednesday on a spacewalk to prepare for the arrival of a new Russian module.

It’s the first spacewalk for both Oleg Novitsky and Pyotr Dubrov, who arrived at the space station in April, and it's expected to last about 6 1/2 hours.

The two needed to get the space station ready for the undocking and disposal of the Pirs docking compartment, which will be replaced later this year by the new Nauka (Science) multipurpose laboratory module.

They have already replaced a fluid flow regulator and also need to replace biological and material science samples on the exterior of the Russian modules.

The two Russians currently team up at the space outpost with NASA astronauts Mark Vande Hei, Shane Kimbrough and Megan McArthur; Japan Aerospace Exploration Agency astronaut Akihiko Hoshide; and European Space Agency astronaut Thomas Pesquet.