The four astronauts of NASA’s Artemis II mission cruised on Monday to the deepest point in space reached by any human, following the tug of lunar gravitational force en route to a rare crewed flyby over the shadowed far side of the moon.

As the climactic six-hour flyby of Earth’s only natural satellite got underway, some two dozen lunar scientists packed a room adjacent to mission control at NASA’s Johnson Space Center in Houston to record the astronauts’ first observations of the moon’s surface in real time.

The Artemis II crew, riding in their Orion capsule since launching from Florida last week, began their sixth day of spaceflight as they awoke at around 10:50 a.m. ET (1450 GMT) to a pre-recorded message from the late NASA astronaut Jim Lovell, who flew aboard the Cold War-era Apollo 8 and Apollo 13 moon missions.

“Welcome to my old neighborhood,” said Lovell, who died last year at age 97. “It’s a historic day, and I know how busy you’ll be, but don’t forget to enjoy the view... good luck and Godspeed.”

The four ⁠Artemis astronauts set a new spaceflight record on Monday as they exceeded the maximum 248,000-mile (400,000 km) distance from Earth reached in 1970 by Apollo 13 after a nearly catastrophic spacecraft malfunction cut short that mission, forcing Lovell and his two crewmates to use the moon’s gravity to help return them safely to Earth.

Later on Monday, the Artemis crew of US astronauts Reid Wiseman, Victor Glover and Christina Koch and Canadian astronaut Jeremy Hansen were due to reach their own farthest distance from Earth - 252,755 miles, some 4,117 miles beyond the record held by the Apollo 13 crew for nearly 56 years.

Naming craters

Along the way, the Artemis crew members spent some time assigning provisional new names to lunar features that previously lacked official designations.

In a radio message to mission control in Houston, Hansen suggested one crater be dubbed Integrity, after the name given to the crew’s Orion capsule, and that another crater sometimes visible from Earth on the cusp between the far and near sides of the moon be named in honor of Wiseman’s late wife, Carroll, who died of cancer in 2020.

“A number of years ago we started this journey, our close-knit astronaut family, and we lost a loved one,” Hansen said of the mission commander’s late spouse, his voice choking with emotion as he described the position of her lunar namesake. “It’s a bright spot on the ⁠Moon, and we would like to call that Carroll.”

As the Orion sailed around the moon’s far side, the crew was expected witness its surface from as close as roughly 4,000 miles above its darkened surface as it eclipsed what would appear to be a basketball-sized Earth in the distant background.

Because the moon rotates at the same speed as it revolves around the Earth, its far side always faces away from our planet, so that few human beings - only members of the Apollo crews who orbited the moon during their missions - have ever gazed directly on its surface.

The milestone marked a major high point of the nearly 10-day Artemis II mission, the first crewed test flight of NASA’s Artemis program, successor to NASA’s 1960s-1970s Apollo ⁠project, and the world’s first voyage to send humans in the vicinity of the moon in more than half a century.

Rare detailed photos

The planned multibillion-dollar series of Artemis missions aims to return astronauts to the moon’s surface by 2028, ahead of China, and establish a long-term US presence there over the next decade, building a moon base that would serve as a proving ground for potential future missions to Mars.

The last time astronauts walked on the moon - a feat so far achieved only ⁠by the United States - was the final Apollo mission in 1972.

Monday’s lunar flyby plunged the crew into darkness and a brief communications blackout as the moon blocked them from NASA’s Deep Space Network, a global array of massive radio communications antennas the agency has been using to talk to the crew.

For the flyby, the astronauts were equipped with professional cameras to take detailed photos of the moon through Orion’s window, showing a rare and scientifically ⁠valuable vantage point of sunlight filtering around its edges.

The crew will also have the chance to photograph a rare moment in which their home planet, dwarfed by their record-breaking distance in space, will set and rise with the lunar horizon as they swing around, presenting a celestial remix of the moonrise typically seen from Earth.