The first ever all-female spacewalk has kicked off at the International Space Station.
US astronauts Christina Koch and Jessica Meir made history on Friday as they floated out of the orbiting space laboratory to replace a faulty power unit.
This is Koch's fourth spacewalk and a first for Meir, who has become the 15th woman to venture out of the ISS and into the vacuum.
It's expected to last five-and-a-half hours.
The duo were assisted by Luca Parmitano of the European Space Agency, who is also the mission commander, and NASA flight engineer Andrew Morgan.
The astronauts exited from the space station's the Quest airlock after their spacesuits were set to battery power.
Koch was the first to leave the hatch followed by Meir.
There have been 227 spacewalkers since the first spacewalk in 1965 and all of them have included a male astronaut or cosmonaut.
The US space agency had originally planned an all-female spacewalk in March, which included Koch and fellow astronaut Anne McClain, but had to cancel it because of a shortage of medium-size suits.
Australian Associated Press