Unveiling NASA’s Authentic Repair Process for Voyager 1 at the Edge of the Heliosphere: No Models, No Testing Equipment, Just Real-Time Testing.

David Cummings, a software developer for NASA’s aircraft systems, described the process of repairing the Voyager 1 spacecraft, which had suffered a 3% memory loss causing system hang-ups. A team from NASA’s Jet Propulsion Laboratory discovered abnormalities since the end of 2023 and found that repairing Voyager was challenging due to the loss of numerous documents and the absence of backup computers for program testing.

In March 2024, the team received a memory dump from the spacecraft and identified a faulty memory chip, rendering all memory units unable to read values. In response to this issue, the team decided to remove the unused EH-12 program to free up memory space. The challenge was that the EH-12 code was scattered throughout the memory unit, requiring the team to rebuild new assembly code to locate and replace the EH-12 code within the faulty memory areas.

Without testing equipment, the team employed a “test by inspection” method, meticulously inspecting the code and collaboratively ensuring no errors were overlooked. The first phase involved reintroducing the telemetry return program to the spacecraft, resulting in successful data transmission, validating the corrective approach and leading to a celebratory milestone. Subsequently, the team transferred the code for scientific data transmission, ultimately restoring the spacecraft’s functionality.

Source: YouTube: Flight Software Workshop

Diagram of the affected memory units and the relocated memory space at various points.

TLDR: David Cummings, a NASA software developer, detailed the complex repair process for Voyager 1, addressing memory loss and system malfunctions by removing unused programs, rebuilding code, and employing meticulous inspection methods for successful spacecraft restoration.