In April 2026, engineers at NASA’s Jet Propulsion Laboratory shut down the Low-energy Charged Particles experiment on Voyager 1, marking another managed step toward the mission’s inevitable silence. As the craft enters its final years of power, its 1977-launched Golden Record remains a functional, billion-year message to the cosmos.
The Managed Silence of a Deep-Space Pioneer
The decision to deactivate the Low-energy Charged Particles instrument in April 2026 was not a failure, but a necessity of physics. Voyager 1, having launched in 1977, is operating on a dwindling supply of plutonium, losing approximately four watts of power annually. For years, mission managers have maintained a rehearsed schedule of power-saving measures to ensure the most critical systems remain active as long as possible.
According to Space Daily, the depletion of the Multi-Mission Radioisotope Thermoelectric Generators (MMRTGs) has forced a shift in operational philosophy. The degradation of the thermocouple junctions within the generators, which convert heat from decaying plutonium-238 into electricity, has reduced the available power budget to a level where the spacecraft can no longer support the thermal and electrical demands of the full instrument suite. The Low-energy Charged Particles (LECP) instrument was specifically chosen for decommissioning because its scientific utility in the current interstellar environment—characterized by low-density plasma and magnetic field fluctuations—has been superseded by the more robust Cosmic Ray Subsystem (CRS) and the Magnetometer (MAG), which remain the final two active scientific payloads.
“While shutting down a science instrument is not anybody’s preference, it is the best option available.” Kareem Badaruddin, mission manager at JPL
Despite these shutdowns, the spacecraft continues its journey into interstellar space, currently traveling at roughly 38,000 miles per hour and located nearly 15 billion miles from Earth. Two instruments remain operational, providing data from a region of space that no other human-made object has ever reached. However, officials anticipate that by the 2030s, the power will run low enough that the radios will go silent, leaving the craft to drift indefinitely.
Engineering a Message for Geological Time
While the spacecraft’s electrical systems are ephemeral, the mission designers prioritized longevity for the Voyager Golden Record. The record is a 12-inch gold-plated copper disk, sealed within an aluminum cover and bolted to the hull of each probe. Unlike the digital data streams sent back to Earth, this analog message was designed to survive for approximately one billion years.
The selection of contents, as reported by Space Daily, was led by Carl Sagan of Cornell University and included a curated montage of humanity. The disk contains 115 encoded images, a 90-minute music selection, and spoken greetings in 55 languages. The linguistic range is intentionally broad, stretching from ancient Akkadian to modern Wu Chinese.
The contents were not intended to be a perfect census of human culture, but rather a snapshot of human diversity as understood by a specific committee in 1977. Frank Drake, the astronomer who chaired the selection committee, worked alongside Sagan and Timothy Ferris to ensure the inclusion of both biological and cultural data. The images were encoded in analog, requiring a needle—provided with the record—to be moved across the surface at 16.67 revolutions per minute to reconstruct the visual data.
“The spacecraft will be encountered and the record played only if there are advanced spacefaring civilizations in interstellar space. But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet.” Carl Sagan, via NASA
The Built-in Clocks of the Golden Record
The record’s cover serves more than a decorative function; it acts as a sophisticated chronometer for any potential finder. According to Space Daily, the cover holds an ultra-pure sample of uranium-238, which has a half-life of roughly 4.5 billion years. By measuring the ratio of uranium-238 to its daughter products, a sufficiently advanced civilization could calculate exactly how much time has elapsed since the spacecraft was launched.
This radioactive clock is paired with a second, independent system: a pulsar map. The map illustrates the position of the Sun relative to 14 pulsars, including their rotation periods in binary. Because pulsars spin down at predictable rates, comparing the current rotation of these stars against the data etched on the cover allows a finder to verify the age of the record. The redundancy is intentional; by checking the uranium decay against the pulsar timing, a finder could gain high confidence in the record’s origin date. Researchers at the time, including Linda Salzman Sagan, noted that the pulsar map was specifically chosen because the period of a pulsar is a universal constant, unaffected by the relativistic effects that might otherwise distort a time-keeping measurement over interstellar distances.
Intimacy and Human Expression in the Deep Void
Beyond the scientific instruments and the radioactive clocks, the record carries deeply personal artifacts. The montage includes natural sounds—wind, surf, thunder, and animal calls—alongside cultural markers like a mother nursing a baby and the first cry of a newborn.
Perhaps the most unusual item is the neurological recording of Ann Druyan, the project’s creative director. Hooked to an EEG, she meditated on the history of civilization and her own personal life, including her recent engagement to Carl Sagan. The team theorized that if a civilization were advanced enough to recover the craft, they might eventually possess the technology to decode brainwave patterns. The recorded data, which includes her heartbeat and the electrical impulses of her brain, serves as a bridge between the physical craft and the subjective experience of being human.
The linguistic greetings, too, capture a specific human moment. The inclusion of 55 languages was designed to represent the global linguistic tapestry, though the team faced significant logistical constraints in sourcing high-fidelity recordings for every dialect. The selection committee ultimately prioritized languages that represented the broadest possible geographic and historical reach, ensuring that even if a language were to die out, its phonetic structure remained preserved in the deep-space archive.
“Hello from the children of planet Earth.” Nick Sagan, record contributor
As the Voyager probes continue their transit through the interstellar medium, they carry these traces of Earth—a “12-inch gold-plated copper disk containing sounds and images selected to portray the diversity of life and culture on Earth,” as NASA describes it. Long after the power cells fade and the last bits of data cease to arrive at the Deep Space Network, the records will continue to travel, representing a moment in time when humanity looked outward and decided to speak. The mission’s legacy is now defined by this transition from an active scientific observer to a passive interstellar monument, a trajectory that began with the primary mission in 1977 and will continue, unpowered, for billions of years.
