WATCH: In first, spacewalk conducted by two women

NASA Astronauts Spacewalk Outside the International Space Station on Oct. 18

WASHINGTON - The first ever spacewalk with an all-female team began Friday, footage broadcast by NASA showed.

US astronauts Christina Koch and Jessica Meir's mission to replace a power controller outside the International Space Station officially began at 1138 GMT.

"Christina, you may egress the airlock," spacecraft communicator Stephanie Wilson told the two.