NASA Voyager 1 returns to full operations after communication issue

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NASA Voyager 1 returns to full operations after communication issue
by Clarence Oxford
Los Angeles CA (SPX) Nov 27, 2024

NASA's Voyager 1 spacecraft has successfully resumed normal operations following a communication disruption last month. The issue arose when the spacecraft unexpectedly switched from its primary X-band radio transmitter to a weaker S-band transmitter, a change that temporarily halted the transfer of science and engineering data. The distance of Voyager 1 - approximately 15.4 billion miles (24.9 billion kilometers) from Earth - compounded the challenge of resolving the problem.

Earlier this month, mission engineers reactivated the X-band transmitter, restoring data collection from Voyager 1's four operational science instruments. As of the week of November 18, regular data transmission resumed, and the team is finalizing tasks to bring the spacecraft fully back to its pre-incident status, including the reset of its computer synchronization system.

The X-band transmitter had been deactivated by the spacecraft's fault protection system, triggered by the activation of a heater. The system is designed to preserve power for critical operations when energy availability drops. Given Voyager 1's extremely limited power supply, most nonessential systems have already been shut down, leaving the fault protection system to disable the X-band transmitter and enable the lower-power S-band transmitter.

Both Voyager spacecraft are operating with razor-thin power margins, relying on electricity generated by the heat from decaying plutonium. This power source decreases by about 4 watts annually, leading the mission team to turn off all remaining noncritical systems over the years. Despite this, the probes' science instruments have continued to function even in temperatures colder than their original design specifications.

The engineering team employs computer models to estimate the power usage of various systems, but these models include inherent uncertainties due to the components' age and unpredictable behavior. In recent years, the declining power supply has necessitated difficult decisions, such as shutting down one of Voyager 2's science instruments earlier this year. On Voyager 1, multiple instruments were deactivated in 1990 after its flybys of Jupiter and Saturn, leaving four still operational to study interstellar particles, plasma, and magnetic fields.

Having traveled for more than 47 years, Voyagers 1 and 2 are the only spacecraft operating in interstellar space. However, their advanced age presents ongoing technical and operational challenges for NASA's mission team.