Italian Samantha Cristoforetti became the first European woman astronaut to embark on a spacewalk outside the International Space Station on Thursday, NASA footage showed.
Cristoforetti was joined by Russian cosmonaut Oleg Artemyev on the spacewalk which began just before 1500 GMT, with the pair expected to spend around six and half hours more than 400 kilometres (248 miles) above Earth.
Among their tasks is work on a Europe-made robotic arm which just a week ago became embroiled in tensions between Russia and the West over Moscow's war in Ukraine.
Early last week the head of Russian space agency Roscosmos Dmitry Rogozin, furious at the European Space Agency's decision to cut ties with Moscow on a Mars rover mission, told cosmonauts on the ISS to stop using the European Robotic Arm.
But President Vladimir Putin dismissed Rogozin as Roscosmos chief on Friday, and hours later Washington and Moscow said they would renew flights together to the ISS.
On Thursday, the spacewalkers will continue work on setting up the robotic arm, which was installed a few months ago after being launched into orbit in July 2021 following numerous delays.
The 11-metre long robot, which looks like a pair of compasses, is one of three such robots on the ISS, but it is the only one that can reach the station's Russian segment.
Once fully set-up, the arm will perform numerous tasks mostly on the Russian segment, and can be controlled from inside or outside the space station, or even from back on Earth.
Thursday was the third spacewalk that involved work on the arm.
The pair will also carry out work on the Russian Nauka laboratory module.
It was Artemyev's sixth spacewalk, but his first not alongside a fellow Russian.
Cristoforetti, a 45-year-old European Space Agency astronaut and former Italian air force pilot, arrived for her second tour on the ISS in April.
She holds the record for the longest stay in space by a woman after spending 199 days in orbit in 2014 and 2015.
The ISS space station has long symbolised closer ties between Russia and the US in the aftermath of the Cold War.
Now it remains one of the last areas of cooperation between Russia and the West, which has imposed sanctions over Moscow's war in Ukraine.