Astronauts Butch Wilmore and Suni Williams are conducting a spacewalk outside the International Space Station to remove degraded hardware and swab for microorganisms.

"Here we go," Mr Wilmore remarked as he exited the station, 420 kilometres above Earth, in a video livestreamed by NASA on X.

NASA astronauts Sunita Williams and Butch Wilmore, stranded in space for eight months, conducted their first spacewalk.