Astronauts from both the U.S. space agency, NASA, and the European Space Agency ((ESA)) left the International Space Station ((ISS)) Wednesday to begin a project to upgrade the floating laboratory’s solar panel power supply system.
NASA flight engineer Shane Kimbrough and ESA astronaut Thomas Pesquet worked for several hours to install the first two of six ISS Roll-Out Solar Arrays (iROSAs)) to ultimately upgrade six of the station’s eight power channels.
NASA says the current solar arrays are functioning well but were designed for a 15-year service life and are in their 21st year of service. The new solar arrays will be positioned in front of six of the current arrays, increasing the station’s total available power from 160 kilowatts to a maximum of 215 kilowatts.  
The electrical boost will be needed to accommodate paying passengers and film crews expected to visit the ISS later this year.
Pesquet and Kimbrough will install two more of the new solar arrays Sunday.