Earth as seen from the Orion capsule in a new image taken last week
No one has ever been farther from home than the Artemis astronauts.
As the Earth becomes increasingly distant in their rear-view mirror, the crew has maintained constant communication with mission control in Houston, Texas. The steady, calm messages from the NASA team have provided the astronauts with a reassuring connection to home.
However, as the spacecraft passes behind the Moon at approximately 23:47 BST (18:47 EDT) on Monday, the Moon itself will block the radio and laser signals that enable two-way communication between the Orion capsule and Earth.
For roughly 40 minutes, the four astronauts will be isolated, each alone with their own thoughts and emotions, traveling through the darkness of space. This will be a profound moment of solitude and silence.
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Artemis pilot Victor Glover expressed hope that the world would use this period of silence as an opportunity for unity.
"When we're behind the Moon, out of contact with everybody, let's take that as an opportunity," he told before the mission. "Let's pray, hope, send your good thoughts and feelings that we get back in contact with the crew."
More than 50 years ago, Apollo astronauts also experienced the isolation caused by a loss of signal during their lunar missions.
Perhaps the most notable example was Apollo 11's Michael Collins.
In 1969, while Neil Armstrong and Buzz Aldrin made history by taking the first steps on the lunar surface, Collins remained alone in the command module orbiting the Moon.
As his spacecraft passed behind the far side of the Moon, communication with both the astronauts on the surface and mission control was lost for 48 minutes.
He described this experience in his 1974 memoir Carrying the Fire, stating that he felt "truly alone" and "isolated from any known life," though he did not experience fear or loneliness.
In subsequent interviews, Collins reflected on the peace and tranquility that the radio silence brought, offering a respite from the constant communications with mission control.
More on Artemis II
- First stop, the Moon. Next stop, Mars? Why NASA's mission matters
- Everything you need to know about NASA's Artemis II mission
- Who are the crew - and what are they taking to the Moon?
- Artemis II: Inside the Moon mission to fly humans further than ever
- The spectacular new image of Earth taken by the crew
- 13 Minutes Presents: Artemis II - The BBC's space podcast telling the story of Artemis II, NASA's mission to loop around the Moon.
Back on Earth, the communication blackout will be a tense period for those responsible for maintaining contact with the spacecraft.
At the Goonhilly Earth Station in Cornwall, located in southwest England, a large antenna has been receiving signals from the Orion capsule, precisely tracking its position throughout the journey and relaying this information to NASA headquarters.
Matt Cosby, chief technology officer at Goonhilly, told the BBC:
"This is the first time we're tracking a spacecraft with humans on it.
We're going to get slightly nervous as it goes behind the Moon, and then we'll be very excited when we see it again, because we know that they're all safe."
However, the hope is that such communication dropouts will soon be eliminated. Cosby emphasized that continuous communication will be essential as NASA and other space agencies worldwide work toward establishing a Moon base and expanding exploration efforts.
"For a sustainable presence on the Moon, you need the full comms - you need the full 24 hours a day, even on the far side, because the far side will want to be explored as well," he said.
Programs such as the European Space Agency's Moonlight initiative plan to deploy a network of satellites around the Moon to provide continuous and reliable communication coverage in the future.
During the communication blackout, the Artemis astronauts will focus their attention entirely on the Moon.
They will dedicate this time to lunar observation—capturing images, studying the Moon's geology, and simply admiring its grandeur.
Once they emerge from behind the Moon and communication is re-established, the global community will collectively breathe a sigh of relief.
The history-making astronauts will then be able to share their extraordinary views with everyone back on Earth.
