What's even better than venturing out into the vacuum of space? Landing on the Moon, according to US astronauts Christina Koch and Jessica Meir, the first all-female duo to conduct a spacewalk.

As a child in elementary school, marine biologist Meir recalled drawing pictures of herself standing on the barren world orbiting our own.

"So I think maybe I'll make that my new dream," she told reporters in a live news conference from the International Space Station (ISS).

NASA is seeking to return to the Moon by 2024 on the Artemis 3 mission. Two astronauts will stride its surface, the first time humanity has done so since 1972, and at least one of them will be a woman, the space agency's chief Jim Bridenstine has promised.

NASA astronauts Jessica Meir and Christina Koch embarked on the first all-female spacewalk. Image: NASA

What's more, the woman will be one of the 12 current female members of the astronaut corps, said Bridenstine.

Meir and Koch, both in their forties and recruited in 2013, seem to be natural candidates.

"The idea of having the honor of being the first woman to walk on the Moon is almost too great to fathom," said Koch, 40, when asked by AFP about the subject.

"Of course it would be a dream of mine and has been my entire life, but for now I'll just settle for knowing that I'll probably at least know the first woman to walk on the Moon — hint hint," she continued, winking as she nudged her teammate.

NASA's internal selection process for the historic mission remains a mystery for the time being, even to the astronauts.

"I definitely do not necessarily know the selection process, but I do know that every single person in our office is extremely qualified and whoever does that mission will be the right person for the job and will carry the hopes and dreams of everyone to explore," added Koch.