Artemis II astronauts travel farther from Earth than ever before.

In a video still from NASA, the crew of Artemis II celebrates Easter Sunday by presenting Jeremy Hansen of the Canadian Space Agency with golden astronaut wings. Hansen is the one member of the crew who had not been to space before. (NASA via The New York Times)

By KENNETH CHANG

The Artemis II astronauts have now ventured farther from Earth than anyone else in the history of humanity.

At 1:56 p.m. Eastern time on Monday, their distance from Earth passed 248,655 miles, the record that had been set by Apollo 13 in 1970. For the next few hours, they were to travel farther, reaching a distance of 252,752 miles.

During this mission, the four astronauts have launched to space, tested life support and other important systems of their Orion spacecraft, tangled with the vehicle’s toilet, puzzled over personal computing devices and left low-Earth orbit. They are the first humans to do so since 1972, although they will not land on the moon.

The three Americans and one Canadian aboard Artemis II were set on Monday to make even more history.

First, Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen became the humans who have traveled farthest from Earth. They surpassed the astronauts of Apollo 13, whose lunar mission went awry.

Later, the astronauts were to pass behind the far side of the moon, seeing parts of the moon never observed with human eyes, gathering scientific data on what they spotted. In the process, they were to fall out of radio contact with Earth for about 41 minutes.

As the crew was to come out of its scheduled communications blackout, they stood to have an opportunity to create a moment for a new generation as inspirational as the “Earthrise” of NASA’s Apollo 8 mission in 1968.

Here’s what else to know.

— Going farther: The astronauts officially began the lunar flyby phase of their mission around 2:45 p.m. Monday, starting a period of intensive observation of the lunar surface. As they were to go around the far side of the moon, the astronauts were to reach their maximum distance from Earth at 7:07 p.m., before looping back toward the planet.

— How to watch: NASA is streaming live video coverage of the mission 24 hours a day. You can view it on YouTube, X, the agency’s website and its smart TV apps.

— Radio blackout: When the astronauts were to go around the lunar far side, they were to lose contact with Earth because the moon blocks radio signals from Earth. This was expected to occur at 6:44 p.m. and was no cause for alarm. (During the Apollo missions, the command module repeatedly passed behind the moon, providing some periodic respite from mission control for the astronaut who waited in lunar orbit while his two crewmates walked on the surface.) At 7:02 p.m., the crew was to zip over the moon at an altitude of 4,070 miles, its closest approach.

— Bonus eclipse: After the astronauts came around the far side, they were to experience a 53-minute solar eclipse starting at 8:35 p.m. They were to be able to observe the solar corona from a unique perspective, as well as unusual glimpses of Earth and other planets.

— Five days: The Artemis II mission launched to orbit on the evening of April 1. After a day of testing important systems in a high Earth orbit, the crew flew away from the planet on Day 2. On Days 3 and 4 the astronauts tested other systems and spoke with family. At the end of Day 5 they entered the lunar sphere of influence, where the pull of the moon’s gravity is stronger than Earth’s.