Two Expedition 36 astronauts will venture outside the International Space Station Tuesday. It's the first of two planned walks.
NASA said the walks are needed to prepare the ISS for a new Russian module and perform additional installations on the station's backbone.
Flight Engineers Chris Cassidy of NASA and Luca Parmitano of the European Space Agency will conduct the spacewalks today and on July 16 from the station's Quest airlock.
Each spacewalk is scheduled to last over 6 hours.
Cassidy and Parmitano will replace a space-to-ground communications receiver and wireless video equipment. The astronauts will also install power and cables for a Russian multipurpose laboratory module that will be launched later this year.
The new module will serve as a research facility, docking port and airlock for future Russian spacewalks. It will replace the Pirs module.
Cassidy, who is designated EV1 for the spacewalks, will wear a U.S. extravehicular mobility suit bearing red stripes. Tuesday's spacewalk will be the fifth of Cassidy's career.
Parmitano, who is designated EV2, will wear a spacesuit with no stripes and will make his first spacewalk of his career. At the same time, he will become the first Italian astronaut to walk in space.
Both spacewalkers will wear helmet cameras to provide up close views of their work.