Nasa’s first all-female spacewalk

American astronauts Christina Koch and Jessica Meir are making history after embarking on the first women-only spacewalk.

They are expected to float outside the International Space Station for more than five hours while they repair defective equipment.

Only 14 women have done a spacewalk -- the first was Dr Kathryn Sullivan while onboard the Challenger in 1984. She explains the significance of this milestone.

(Photo: Christina Koch and Jessica Meir prepare for their spacewalk. Credit: Nasa)