At 23:47 BST on Monday, four astronauts will pass behind the Moon and vanish from reach — a fleeting silence that carries the weight of human history and the promise of what comes next
There is a moment, familiar to anyone who has ever watched a ship disappear beyond the horizon or a train slide into a tunnel, when connection gives way to absence. For the crew of Artemis, that moment arrives at 23:47 BST on Monday — and it will be unlike anything experienced by any other human beings alive.
As the spacecraft passes behind the Moon, the radio and laser signals that have tethered the four astronauts to mission control in Houston will be swallowed by 2,000 miles of solid lunar rock. For approximately 40 minutes, no voice, no data stream, no reassuring word from a flight controller will reach them. They will be, in the most absolute sense the word allows, alone — further from home than any human beings in history, travelling through the darkness of space with nothing but each other and their own thoughts for company.
It is, depending on your disposition, either the most terrifying or the most transcendent thing imaginable.
What Happens in the 40 Minutes That Will Stop the World Holding Its Breath
The mechanics of the blackout are straightforward enough. Communication between the Orion capsule and Earth depends on line-of-sight signal transmission. The Moon, vast and indifferent, simply gets in the way. Unlike a technical failure or an emergency, this loss of signal is entirely predictable, meticulously planned for, and utterly beyond the power of either the crew or mission control to prevent or shorten.
What fills those 40 minutes is, in its own way, remarkable. Rather than simply enduring the silence, the astronauts will dedicate the blackout period to focused lunar observation — photographing the surface, studying the Moon’s geology, and gazing at a view that no camera has ever adequately conveyed to those who were not there to see it. The silence, in this sense, becomes purposeful. Without the constant back-and-forth of mission communications, the crew’s attention can be given entirely to the Moon itself.
Artemis pilot Victor Glover, speaking to BBC News before the mission departed, offered something more personal than a technical briefing when asked about the impending blackout. “When we’re behind the Moon, out of contact with everybody, let’s take that as an opportunity,” he said. “Let’s pray, hope, send your good thoughts and feelings that we get back in contact with the crew.” It was the appeal of a man who understood that 40 minutes, in these circumstances, is a long time — and who wanted the world watching to feel, in some small way, that it was sharing the experience rather than merely observing it.
Why Silence in Space Carries a Weight That Words Struggle to Convey
More than half a century ago, another astronaut encountered something very similar — and his account remains the most eloquent testimony we have to what solitude of this magnitude actually feels like.
Michael Collins orbited the Moon alone in the Apollo 11 command module in July 1969, while Neil Armstrong and Buzz Aldrin made their descent to the lunar surface. Each time his craft passed behind the far side, contact with both his crewmates and with mission control vanished for 48 minutes. He described the experience in his 1974 memoir as feeling “truly alone” and “isolated from any known life.” And yet — and this is the detail that has stayed with readers for decades — he did not feel fear. In later interviews, Collins recalled the radio silence as a gift of sorts: a respite from the relentless requests of mission control, a pocket of peace in an otherwise intensely managed existence.
The Artemis crew will carry that legacy into their own passage behind the Moon. Their blackout is shorter — 40 minutes against Collins’s 48 — and they have each other where Collins had no one. But the fundamental experience, the sudden withdrawal of the thread connecting human beings in space to human beings on Earth, remains unchanged by the decades in between. Technology has transformed almost every other dimension of spaceflight. This particular silence has not been engineered away. Not yet.
The Quiet Vigil in Cornwall: Britain’s Role at the Edge of Contact
Back on Earth, the blackout will be experienced rather differently by those whose professional responsibility is maintaining the signal.
At the Goonhilly Earth Station on the Lizard Peninsula in Cornwall, a large antenna has been tracking the Orion capsule throughout its journey — collecting its signals, pinpointing its position with precision, and feeding that data back to Nasa’s Houston headquarters. Goonhilly, with its history stretching back to the first transatlantic satellite television broadcasts in the 1960s, has in recent years repositioned itself as a hub for deep space communications. The Artemis mission represents a significant milestone in that ambition: it is the first time the station has tracked a spacecraft carrying human beings.
Matt Cosby, Goonhilly’s chief technology officer, was candid about what the blackout will feel like from the ground. “We’re going to get slightly nervous as it goes behind the Moon,” he told the BBC, “and then we’ll be very excited when we see it again, because we know that they’re all safe.” There is something quietly affecting about that formulation — the way in which the re-establishment of a signal becomes synonymous, for those watching, with proof of life. The antenna at Goonhilly will not be searching for data when Orion re-emerges from the Moon’s shadow. It will be searching for reassurance.
That Cornwall should play any role at all in a mission of this magnitude is a detail worth dwelling on. Britain’s contribution to the infrastructure of deep space exploration is neither loud nor celebrated in proportion to its significance. Goonhilly’s involvement in Artemis is a reminder that the architecture supporting human spaceflight is more distributed, and more internationally collaborative, than the Houston-centric narrative of American space history tends to suggest.
From Blackout to Moon Base: Why Eliminating the Silence Has Become a Strategic Imperative
The 40-minute communication gap is, for this mission, an accepted and manageable constraint. For the future that Nasa and its international partners are now actively planning, it is something closer to a fundamental problem.
A permanent lunar base — which remains the stated long-term ambition behind the entire Artemis programme — cannot function on the basis of predictable communication blackouts. Continuous connectivity is not a convenience in that context; it is an operational necessity. The far side of the Moon, which offers unique conditions for radio astronomy and scientific observation precisely because it faces permanently away from Earth’s electromagnetic noise, will be among the most scientifically valuable locations for future exploration. It is also, by definition, permanently out of direct line-of-sight contact with Earth.
Cosby put the challenge plainly. “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.” The solution being developed is a satellite relay network — a lunar equivalent, in essence, of the infrastructure that enables mobile phone coverage in areas where direct transmission is impossible. The European Space Agency’s Moonlight programme is among the initiatives planning to deploy exactly such a network of satellites in lunar orbit, providing continuous and reliable coverage across the entire surface.
When that infrastructure exists, the kind of silence the Artemis crew will experience on Monday night will become a historical curiosity rather than an operational reality — a relic of the early years of human return to the Moon, recalled the way we now recall the days when transatlantic telephone calls required booking in advance and hoping the line would hold.
For now, though, the silence remains. At 23:47 BST on Monday, four human beings will slip behind the Moon and become, for 40 minutes, the most unreachable people who have ever lived. The world will wait. Cornwall will listen. And when the signal returns — when Goonhilly’s antenna picks up the first data from an Orion capsule emerging back into contact with Earth — the collective exhale will be felt as much as heard.
After that, the astronauts will have something to share: images, observations, and the kind of first-hand account that no instrument can replicate. But the 40 minutes of silence itself — that will belong only to them.
