Voyager 1 sends reasonable data again – Kosmonautix.cz

After some ingenious searching, the Voyager 1 control team was able to check the status of the most distant man-made object’s onboard systems for the first time in five months. For the first time since last November, Voyager 1 has again started sending reasonable and usable data about the state of individual systems. However, the journey does not end there. The next step will involve attempts to return the probe back to a mode in which it would start collecting scientific data again. Voyager 1 and its sister probe Voyager 2 are the only man-made probes that have reached what is known as interstellar space. Their importance for scientific research is therefore unquestionable.

On November 14, 2023, Voyager 1 stopped sending intelligible science and engineering data to Earth. The engineers verified that the problem was only in the transmission of this data to Earth when they found that the probe was still receiving instructions and was generally functioning normally. In March of this year, a team of engineers from Jet Propulsion Laboratory in Southern California has confirmed that the current issue is with one of the three on-board computers called the FDS (flight data subsystem). The task of the FDS is to provide the “packaging” of scientific and engineering data that is intended to be sent from the probe towards planet Earth.

The experts were able to determine that the single chip responsible for storing part of the FDS system memory (including the software code of the FDS computer) was not working. The absence of this code made scientific and engineering data unusable. It is clear that it was not possible to physically repair the defective chip remotely, so the team decided to store the necessary code somewhere else in the FDS memory. However, this seemingly logical and in a way simple step had a big catch. However, no storage location was large enough to hold a complete code section.

The Voyager 1 probe
Source: https://www.salon.com/

Therefore, the experts had to prepare a plan to split this code into parts and then store those parts in different locations of the FDS. In order for this plan to work, they also had to adapt these parts of the code to ensure that they would still work together, for example. However, other parts of the FDS memory had to be updated as well, if there were links pointing to the location of the original code.

The team began by tackling the code responsible for packaging engineering data from the probe. After the necessary checks, this code was sent to Voyager 1 on April 18 to be stored in the FDS memory. The signal needed 22.5 hours to overcome the distance of 24 billion kilometers that separates the Earth and Voyager 1. It then took another 22.5 hours for the signal to travel back from the probe to our planet. The team responsible for controlling the probe received a response from Voyager 1 on April 20, and its members could see with their own eyes that the modification had indeed worked. For the first time in five months, they were able to check the status of the on-board systems.

Description of the outer regions of the heliosphere. Both probes are now further away.
Source: https://cs.wikipedia.org

Over the coming weeks, the ground team will address the migration and modifications of other affected parts of the FDS software. Among them are also parts that will allow the resending of scientific data. Voyager 1’s sister probe, Voyager 2, continues to operate normally and without problems. The twins, named Voyager, were launched more than 46 years ago and are currently not only the most distant probes in history, but also the longest-running space probes ever, with both records constantly being pushed. Before the two long-lived space probes reached the aforementioned interstellar environment, they made flybys of Jupiter and Saturn. In addition, Voyager 2 also visited the planets Uranus and Neptune.

Translated from:
https://www.jpl.nasa.gov/

Image Sources:
https://d2pn8kiwq2w21t.cloudfront.net/original_images/1-Voyager_2-copy.jpg
https://blogs.nasa.gov/sunspot/wp-content/uploads/sites/289/2023/12/Voyager-768×432.png
https://mediaproxy.salon.com/…/https://media.salon.com/2021/05/voyager-1-0510211.jpg
https://cs.wikipedia.org/…Voyager_1_entering_heliosheath_region.jpg