For the first time since November, NASA’s Voyager-1 spacecraft has provided usable data to Earth about the state of its on-board systems, reports phys.org. The researchers’ next step is to try to restart the probe so that it can start sending back science data again.
The probe’s twin, Voyager-2, is the only man-made probe ever to reach interstellar space.
Voyager-1 last sent meaningful data to Earth on November 14, 2023, even though mission controllers say the device is still receiving their commands and otherwise functioning properly. In March, NASA’s JPL engineering team confirmed that the problem was related to the Flight Data Subsystem (FDS), one of the spacecraft’s three on-board computers. The FDS is responsible for packaging scientific and technical data before it is sent to Earth by the probe.
According to the researchers, the chip responsible for storing part of the FDS memory is malfunctioning. Thus, the FDS software code was also lost, which rendered the returned scientific and technical data unusable. Since the chip could not be repaired, the team decided to place the affected code elsewhere in the FDS memory. But no space is big enough to fit the code snippet in its entirety.
Therefore, a plan was developed to divide the affected code into sections and store these sections in different locations in the FDS. To make this plan work, they had to modify sections of code to ensure they still functioned as a whole. References to code locations in other parts of the FDS memory also had to be updated.
The team began work by assigning the code responsible for packaging the spacecraft’s engineering data. This was sent to its new location in the FDS memory on April 18th. It takes about 22.5 hours for the signal to reach Voyager 1, which is more than 24 billion kilometers from Earth now, and another 22.5 hours for the signal to return to Earth. When the engineering team received feedback from the spacecraft on April 20, they saw that the modification had worked: for the first time in five months, the spacecraft’s health had been checked.
In the coming weeks, the team will migrate and modify other affected parts of the FDS software. These include those that can then start sending back scientific data as well.
Launched more than 46 years ago, the Voyager probes are the longest-traveling and oldest active spacecraft in history.
