Voyager 1 Sends Data From Interstellar Space Again

After months of silence and tension, NASA has achieved what seemed like a technological miracle. Voyager 1, the most distant human-made object in history, is once again streaming readable science data from interstellar space. This marks the end of a nail-biting period for the Jet Propulsion Laboratory (JPL) team, who had to repair a computer system built in the 1970s from more than 15 billion miles away.

The November Blackout: What Went Wrong?

The trouble began on November 14, 2023. While Voyager 1 continued to signal that it was alive, the message it sent back to Earth became unintelligible. Instead of the usual stream of binary code containing engineering and science updates, the probe began sending a repeating pattern of ones and zeros. It was essentially speaking gibberish.

The issue was traced to the Flight Data System (FDS). This is one of the probe’s three onboard computers. Its job is to package data from the science instruments and engineering telemetry before sending it to the Telemetry Modulation Unit (TMU) for transmission to Earth.

For months, the team at JPL in Southern California tried to troubleshoot the issue. The situation was dire because Voyager 1 is operating on hardware designed nearly 50 years ago. Losing the FDS meant losing all insight into the spacecraft’s health and the unique environment of interstellar space it occupies.

The "Poke" That Saved the Mission

In March 2024, the engineering team attempted a “poke” command. This was designed to prompt the FDS to try different sequences in its software package in case a corrupted section was causing the loop.

The result was a breakthrough. The spacecraft responded with a memory dump that looked different from the repeating pattern. While it wasn’t standard data, an engineer with the Deep Space Network was able to decode it. This revealed the exact cause of the problem:

  • A single chip responsible for storing a portion of the FDS memory had failed.
  • This chip contained the software code that the computer needs to process data.
  • Because the chip failed, the code was corrupted, leading to the communication loop.

Since the team could not physically travel 15 billion miles to replace the hardware, they had to find a software solution to a hardware failure.

The Solution: A Code Transplant

The fix required creativity. The team decided to move the affected code to a different location in the FDS memory. However, there was a catch. No single location in the remaining memory was large enough to hold the entire section of code at once.

The engineers devised a plan to slice the code into sections. They stored these chunks in different places within the FDS. This was a high-risk operation. They had to update every reference in the code to ensure the broken-up pieces would still find each other and function as a cohesive whole.

The timeline of the recovery was a testament to patience and precision:

  • April 2024: The team sent the first batch of commands to move the code responsible for engineering data. It worked. For the first time in five months, NASA could see the health and status of the probe.
  • May 2024: Encouraged by the success, the team sent the second command to fix the science data return.
  • Late May 2024: The fix was successful. Two of the four science instruments began sending usable data immediately.
  • June 2024: NASA confirmed that all four remaining science instruments were back online and returning readable data.

The Challenge of Distance

Repairing a computer from Earth is standard procedure for satellites. Repairing Voyager 1 is a logistical nightmare due to the sheer distance.

Voyager 1 is roughly 15.1 billion miles (24.3 billion kilometers) from Earth. At this distance, radio signals traveling at the speed of light take about 22.5 hours to reach the spacecraft.

This creates a agonizing 45-hour delay for every command sent:

  1. Engineers send a command.
  2. They wait 22.5 hours for it to arrive.
  3. The spacecraft executes the command.
  4. Engineers wait another 22.5 hours to receive the confirmation signal.

Every step of the troubleshooting process required two days of waiting to see if it worked. This slow-motion dialogue makes the successful repair even more impressive.

What Science Is Voyager 1 Collecting Now?

Now that the probe is fully functional, it has resumed its primary mission. Voyager 1 crossed the heliopause (the boundary of our solar bubble) in 2012, entering interstellar space. It is currently the only probe sending data from this region.

The four instruments currently operational and returning data are:

  1. Plasma Wave Subsystem: Measures the density of the interstellar plasma.
  2. Magnetometer: Maps the magnetic field lines in the space between stars.
  3. Cosmic Ray Subsystem: Detects high-energy particles originating from outside our solar system.
  4. Low-Energy Charged Particle Instrument: Measures the energetic particles in the probe’s environment.

This data provides scientists with the only direct measurements of the environment outside our sun’s magnetic influence.

Future Outlook: How Long Do We Have?

While this glitch has been resolved, Voyager 1 is operating on borrowed time. The spacecraft is powered by a radioisotope thermoelectric generator (RTG), which converts heat from decaying plutonium into electricity. This power source loses about 4 watts of power per year.

To keep the probe running, mission controllers have been gradually turning off non-essential systems, including heaters that keep the instruments warm. Surprisingly, many instruments have continued to work despite dropping well below their tested temperature limits.

Estimates suggest that by the late 2020s or roughly 2030, the power levels will drop too low to operate even a single science instrument. Until then, every bit of data Voyager 1 sends back is a new discovery.

Frequently Asked Questions

How old is Voyager 1? Voyager 1 was launched on September 5, 1977. It has been operating for over 46 years.

What is the Golden Record? Both Voyager 1 and 2 carry a 12-inch gold-plated copper disk containing sounds and images selected to portray the diversity of life and culture on Earth. It is intended as a message to any extraterrestrial intelligence that might find it.

Is Voyager 2 also having problems? Voyager 2 is currently operating normally. It is slightly closer to Earth than Voyager 1 (about 12.6 billion miles away) and continues to return data from interstellar space.

Why can’t they just reboot the system? They did try resetting the system, but the issue was a physical hardware failure (a corrupted memory chip), not a temporary software glitch. A simple reboot returns the system to the same broken state because the memory storage itself is damaged.