Woman astronaut surrounded by electronics (NASA)
NASA astronaut Anne McClain is seen inside the Destiny laboratory module surrounded by exercise gear during a workout session aboard the International Space Station. (NASA)

U.S. space agency NASA will send astronauts Anne McClain, 39, and Christina Koch, 40, on NASA’s first women-only spacewalk on March 29.

The all-female spacewalk will be supported by a female ground crew: Mary Lawrence will serve as lead flight director and Jackie Kagey will be lead spacewalk flight controller at NASA’s Johnson Space Center in Houston.

It’s a fitting milestone for Women’s History Month, although NASA says the timing is coincidental.

Both McClain and Koch were part of NASA’s 2013 astronaut class, which was 50 percent female. While women make up a growing number of astronauts, they’re still underrepresented in the field of space travel — for now.

McClain, a major in the U.S. Army, was a helicopter pilot who flew combat missions for many years. “I was blessed to have parents who never put qualifiers on what I could do,” she said in a U.S. Army video posted on her Twitter account.

Working for NASA, McClain said, “we don’t do the same thing any two days” in a row.

Smiling female astronaut in space suit (Beth Weissinger/NASA)
Christina Koch listens to questions before her flight to the International Space Station. (Beth Weissinger/NASA)

“We could be [training] in the water in a spacesuit on Monday, and in Russian language class on Tuesday, and then we’re sitting in Mission Control, talking to [the International] Space Station on Wednesday,” she said. (Astronauts traveling to the International Space Station must hitch a ride on Russia’s Soyuz spacecraft, so Russian language skills are required.)

Koch, like McClain, has undergraduate and advanced degrees in engineering.

She began developing space-science instruments at NASA, and later worked in Antarctica for a year, conducting experiments and helping with research.

Her experience in Antarctica proved valuable, she said, because there are many parallels to the work done by astronauts, in terms of “the harshness of the environment and the mental and physical … fortitude it takes to be successful” there.

The March 29 spacewalk will last about seven hours, according to NASA.