ESA (European Space Agency) astronaut Thomas Pesquet and NASA astronaut Shane Kimbrough have begun their spacewalk outside the International Space Station to install and deploy the first new ISS Roll-Out Solar Array (iROSA).

The spacewalkers switched their spacesuits to battery power at 7:42 a.m. EDT to begin the spacewalk, which is expected to last about six-and-a-half hours.

Watch the spacewalk on NASA TV on the NASA app and the agency’s website.

Pesquet is extravehicular crew member 1 (EV 1), wearing a spacesuit bearing red stripes and using helmet camera #20. Kimbrough is extravehicular crew member 2 (EV 2), wearing the unmarked spacesuit and helmet camera #22.

Pesquet will take lead moving to the P6 worksite, the pair will both work to unfold the new solar array on the 2B power channel, and Kimbrough will drive in the two remaining bolts to secure the solar array in place. Then, the pair will mate cable to connect the array to the station’s power supply to complete deployment. If time allows, the spacewalkers will turn to get-ahead tasks for the second iROSA installation.

This is the fourth spacewalk Kimbrough and Pesquet have conducted together, following the recent spacewalk that initiated the first iROSA upgrade, and including two Expedition 50 spacewalks in January and March 2017 that included another station power upgrade, replacing nickel-hydrogen batteries with new lithium-ion batteries.

This is the 240th spacewalk in support of space station assembly.

Learn more about station activities by following the space station blog, @space_station and @ISS_Research on Twitter as well as the ISS Facebook and ISS Instagram accounts.