The four astronauts on NASA’s Artemis II lunar mission are heading back to Earth after their Orion capsule passed the point where Earth’s gravity outweighs the moon’s pull, the U.S. space agency said.

The crew – U.S. astronauts Christina Koch, Victor Glover and Reid Wiseman, along with Canada's Jeremy Hansen – are due to splash down off the coast of San Diego Friday after completing the first lunar fly-by in more than 50 years.

During their return, the astronauts briefly spoke with colleagues aboard the International Space Station (ISS) via an audio link.

Asked how she found the view of Earth and the moon, Koch said she was struck not only by Earth's beauty but also by the surrounding darkness, which made the view even more remarkable.

Koch and ISS astronaut Jessica Meir previously took part in the first all-female spacewalk in 2019. "Jessica, I always hoped we would be in space again together, but I never thought it would be like this," Koch said.

Glover said the Orion capsule offered far less space than the ISS, adding that everything they did began with space constraints.

The Artemis 2 crew launched aboard NASA's Space Launch System rocket from Cape Canaveral, Florida, Wednesday evening and flew around the Moon, reaching a greater distance from Earth than any humans before them.