By Evie Carrick
October 16, 2019

At 7:38 a.m. on Friday, history was made as two female astronauts headed out of the International Space Station in what would be the first all-female spacewalk.

Christina Koch and Jessica Meir's mission is to replace a failed power controller, known as the battery charge/discharge unit, according to NASA. Their task will take place over the course of approximately five hours.

You can watch their mission here.

NASA All-Female Spacewalk
Credit: Courtesy of NASA

Congratulatory messages and well-wishes poured in over social media, leading the hashtag #AllWomenSpaceWalk to trend on Twitter. The milestone is Meir's first spacewalk and Koch's fourth.

Koch is the fourteenth woman to walk in space since in NASA's over 200 spacewalks since 1998.

The historic event — scheduled for Koch and astronaut Anne McClain — was previously slated for March and was shelved “due in part to spacesuit availability on the station,” according to a statement from NASA at the time. McClain required a medium-sized space suit while only larges were available.

For the March walk, McClain was replaced by male astronaut Nick Hague.

Nine spacewalks are planned for the remainder of 2019.

NASA All-Female Spacewalk
Credit: Courtesy of NASA

"Astronauts typically spend about 6.5 hours spacewalking, not including the time it takes to prepare to float out of the hatch," NASA explained. "Spacewalking is one of the most dangerous tasks performed during an astronaut’s mission, and to ensure top performance, safety and range of motion during the intense process that is a spacewalk, a properly fitting spacesuit is key."

Koch and Meir’s mission is being supported by crew members Andrew Morgan, Alexander Skvortsov, Luca Parmitano, and Oleg Skripochka.

Fellow astronaut and Expedition 61 member Morgan tweeted, "So proud of my astrosisters @Astro_Christina and @Astro_Jessica! We’ve been training together since our selection in 2013, and now they’re out on a history-making spacewalk! #AllWomanSpacewalk"