NASA has just approved an all-women spacewalk, which will take place on Friday. This is the first time that a crew doing a spacewalk will comprise only of female astronauts.

And it is not just a symbolic gesture by the space agency. They will actually make a very important repair to the International Space Station. Astronauts Christina Koch and Jessica Meir will move out of the orbiting research platform and fix a key part of the ISS' electrical systems.

The spacewalk was expected to have taken much earlier, but a fault in the battery charge/discharge unit delayed NASA's plans and new batteries had to be installed on the ISS.

The BCDU has to be replaced before any battery can be changed. It is not a safety issue, but still an urgent one. The ISS is currently using solar panel arrays to power itself. The BCDU regulates how much electricity is fed into each battery of the ISS.

It is a very straightforward repair mission. The two astronauts will be venturing out of the Quest Joint Airlock which is the primary airlock of the ISS. It also contains space suits and enables astronauts to perform a spacewalk without the shuttle being docked in the ISS. The whole repair mission is expected to take close to five and a half hours.

Commander Luca Parmitano of the European Space Agency will be operating the Canadarm 2 robotic arm for the repairs. NASA engineer Andrew Morgan will be responsible for providing airlock and spacesuit support.

The space agency has also released a YouTube video announcing the spacewalk.

The first spacewalk done by a woman happened 35 years ago. Russian astronaut Savitskaya performed it in July 1984. The first American to do it was Kathy Sullivan, who performed it in October of the same year. To date, 12 women have completed 40 different spacewalks.

Christina Koch will be on her fourth spacewalk, while Jessica Meir will be performing her first one.

NASA Orion Space Suit
Advance space suit engineer, Kristine Davis, is helped out of a space suit after a press conference displaying the next generation of space suits as parts of the Artemis program in Washington Photo: AFP / Andrew CABALLERO-REYNOLDS Andrew Caballero-Reynolds/AFP

The live coverage from the mission will be streamed on NASA TV and NASA.Gov/Live at 6:30 PM ET (11:30 PM BST).