In a giant leap for womankind, two women are conducting a spacewalk together for the first time in history.
NASA astronauts Jessica Meir and Christina Koch embarked on their mission outside of the International Space Station to replace a faulty battery charge/discharge unit.
This spacewalk makes Ms Meir the 15th woman overall to complete one and 14th US woman to do so.
It was the fourth spacewalk for Ms Koch.
NASA is currently live streaming the event on their YouTube account.
The mission can take anywhere between five to six hours and according to NASA, they’re not easy.
NASA’s website said, “astronauts typically describe them as the most physically challenging thing they do”.
This also isn’t the first time US astronauts have attempted to conduct an all-female spacewalk.
Back in March this year, NASA was forced to cancel a spacewalk that would have included Ms Koch and fellow astronaut Anne McClain.
It didn’t go ahead because their spacesuits were not properly fitted.
Both Ms Koch and Ms Meir were selected as astronaut candidates in 2013 on their first spaceflight.
‘Hopefully this will now be considered normal’
NASA leaders and others around the world have cheered Ms Koch and Ms Meir on.
At the same time, many noted that this will hopefully become routine in the future. America’s first female spacewalker from 35 years ago, Kathy Sullivan, was delighted.
She said It’s good to finally have enough women in the astronaut corps and trained for spacewalking for this to happen.
“We’ve got qualified women running the control, running space centres, commanding the station, commanding spaceships and doing spacewalks,” Ms Sullivan said earlier this week.
Tracy Caldwell Dyson, a three-time spacewalker who watched from Mission Control, added: “Hopefully, this will now be considered normal.”
NASA Administrator Jim Bridenstine watched the big event unfold from NASA headquarters in Washington.
“We have the right people doing the right job at the right time,” he said.
“They are an inspiration to people all over the world including me. And we’re very excited to get this mission underway.”
Ms Koch and Ms Meir were supposed to install more new batteries in a spacewalk next week, but had to venture out three days earlier to deal with an equipment failure that occurred over the weekend.
“Jessica and Christina, we are so proud of you. You’re going to do great today,” fellow astronaut Andrew Morgan radioed from inside as the women exited the hatch.
Ms Koch is going to remain in space for an extended duration mission of 11 months, which will set a new record for longest single spaceflight by a woman. It’s an expected total of 328 days in space.
She will also provide researchers the opportunity to observe the effects of a long-duration spaceflight on a woman to prepare for human missions to the Moon and Mars.