Christina Koch and Jessica Meir Complete the First All-Woman Spacewalk

On October 18, 2019, NASA astronauts Christina Koch and Jessica Meir made history outside the International Space Station. Working together for seven hours and seventeen minutes, they completed the first spacewalk carried out entirely by women. Their mission combined an important equipment repair with a milestone in human spaceflight.

Restoring a Vital Power Component

The astronauts’ main task was to replace a faulty battery charge-discharge unit, known as a BCDU. This equipment helps manage the batteries that store energy collected by the station’s solar arrays, allowing its systems to operate when the station passes through Earth’s shadow.

The unit had failed to activate after the installation of new lithium-ion batteries. Although the failure had not endangered the crew or interrupted station operations, it prevented the new batteries from providing their intended increase in available power.

Koch and Meir installed a replacement, which mission control activated and confirmed was working properly. They also completed additional maintenance work outside the station.

Two Astronauts, One Historic Partnership

For Meir, this was her first spacewalk; for Koch, it was her fourth. Both had joined NASA’s astronaut class of 2013, the agency’s first class with equal numbers of women and men.

Their work depended on a wider team. Inside the station, fellow astronauts provided spacesuit and airlock assistance and operated the robotic arm, while specialists on Earth supported the operation.

A New Chapter in Spaceflight

Women had been performing spacewalks since 1984, when Soviet cosmonaut Svetlana Savitskaya became the first, followed later that year by American astronaut Kathryn Sullivan. The achievement in 2019 was the first pairing of two women for an entire spacewalk.

By successfully completing their repair, Koch and Meir added a new milestone to that history through the practical, demanding work of maintaining a laboratory in orbit.