NASA has recently powered down one of Voyager 1’s last remaining scientific instruments in an essential move to conserve energy. This decision comes as the spacecraft, which has been in operation for nearly 50 years, approaches a crucial phase aimed at extending the life of both Voyager probes.
Navigating Power Challenges
On April 17, 2023, Voyager 1 was commanded to switch off its Low-Energy Charged Particle (LECP) instrument. This device, operational for 49 years, has been essential in studying the ions, electrons, and cosmic rays in its vicinity. However, Voyager 1 is now critically low on power after an unexpected drop during a roll maneuver on February 27.
Voyager’s Historic Journey
Launched in 1977, Voyager 1’s primary mission was to explore Jupiter and Saturn. Its journey has since been extended multiple times. In 2012, it became the first human-made object to enter interstellar space, maintaining its status as the most distant spacecraft from Earth.
Voyager 2 followed, entering interstellar space about six years later and continuing to send valuable data. Both spacecraft rely on a radioisotope thermoelectric generator, which converts decaying plutonium into electrical power, losing approximately 4 watts annually.
Energy Conservation Strategies
NASA’s Jet Propulsion Laboratory (JPL) has indicated that power margins for Voyager 1 have become extremely narrow. This situation necessitates the shutdown of various instruments and heaters to prevent freezing of critical components.
- Currently, only two of Voyager 1’s ten scientific instruments remain operational.
- Voyager 2 still has three instruments running.
- Instruments are crucial for understanding conditions beyond our solar system and the heliopause, the boundary where solar wind interacts with the interstellar medium.
The “Big Bang” Approach
The recent shutdown of the LECP instrument is projected to give Voyager 1 an additional year of functionality. To optimize power resources, JPL plans to implement a “Big Bang” procedure. This method involves simultaneously shutting down several devices and replacing them with lower-power alternatives, effectively managing the spacecraft’s thermal conditions while still collecting scientific data.
Two instruments aboard Voyager 1 are currently monitoring magnetic fields and plasma waves. The hope is that the “Big Bang” procedure will allow for the reactivation of the LECP. Notably, engineers are maintaining a low-power motor for the LECP, keeping the option open for future use.
Future Missions and Commands
Tests related to the “Big Bang” strategy are slated for Voyager 2 in May and June 2023, benefiting from greater power reserves and proximity to Earth. If these tests yield positive results, Voyager 1’s “Big Bang” execution could occur as early as July. Commands sent to Voyager 1 take approximately 23 hours to reach the spacecraft, situated 15 billion miles (25 billion kilometers) away from Earth.
After JPL transmitted the shutdown commands, the LECP completed its shutdown process in just over three hours. Restarting the instrument, considering the frigid conditions and vast distance, poses a significant challenge.
