NASA astronauts Christina Koch and Jessica Meir are making history today. The pair are currently carrying out the first all-female spacewalk in the history of the International Space Station, performing some much-needed maintenance on the high-tech orbiting laboratory.

As is often the case, the spacewalk is being livestreamed by NASA, with cameras attached to both astronauts as well as external cameras affixed to the ISS itself. You can watch the lengthy operation live as it happens right here.

The livestream, which you can watch in the window below, includes commentary from NASA as well as a live audio stream of the communication between the astronauts and their support staff back on Earth.

When NASA was forced to scrub what would have been the first all-female spacewalk in history due to spacesuit sizing issues back in March, it was a serious letdown for many. The spacewalk still happened, with astronaut Nick Hague being swapped in for McClain, but the milestone had to be delayed.

NASA and even McClain herself made it clear that the decision was business as usual for the space program. NASA has to prioritize crew safety and efficiency over “firsts” that wouldn’t ultimately change the work being done, and in this particular case, the last-second spacesuit preference change made it impossible for both women to be safe and comfortable during the work.

Today, Koch and Meir are working on the power systems of the ISS, swapping out a failed power regulator with a spare. The hardware being replaced helps the space station to store solar power in its battery array. It’s these batteries that allow the space station to remain powered even when its solar panels fall into Earth’s shadow.

Two prior spacewalks saw the replacement of old batteries with new models, and that work will continue in three future spacewalks.