On Monday, NASA will announce the names of the astronauts — three Americans and a Canadian — who will fly around the moon next year, marking the beginning of humans’ first return to the lunar surface in half a century. The Artemis II mission is scheduled for November 2024, and the crew of four will fly around the moon, but not on the Moon.

As part of the Artemis program, NASA plans to send astronauts to the moon in 2025, more than 50 years after the historic Apollo missions ended in 1972. In addition to sending the first woman and the first human of color to the moon, the US space agency hopes to establish a permanent human presence on the lunar surface and eventually embark on a journey to Mars.

NASA Administrator Bill Nelson said this week at Axios’ “What’s Next” summit he expects a manned mission to Mars by 2040. The four Artemis II crew members will be announced at an event at 10:00 AM (15:00 GMT) at the Johnson Space Center in Houston.

The 10-day Artemis II mission will test life support systems aboard the Orion spacecraft, as well as NASA’s Space Launch System’s powerful rocket. The first Artemis mission ended in December when the uncrewed Orion capsule returned to Earth after a 25-day journey around the moon.

During its journey around its Earth-orbiting satellite, Orion has traveled more than a million miles (1.6 million kilometers) and farther from Earth than any previous manned spacecraft. At the Axios Summit, Nelson was also asked whether NASA would stick to its program to get astronauts to the moon’s south pole in late 2025.

“Space is tough,” Nelson said. “You have to wait until you realize it’s as safe as possible, because you only live on the fringes. “So I don’t really worry about time,” he said. “We won’t launch until it’s right.” Only 12 people—all white—have set foot on the moon.