NASA Shuts Down Science Instrument on Voyager 1 to Conserve Power

Nasa has taken a difficult but necessary step to keep Voyager 1 operating: shutting down one of its long-running science instruments, as the spacecraft runs critically low on power. The decision, carried out on April 17 by engineers at Jet Propulsion Laboratory, aimed to extend the life of the nearly 49-year-old probe, which continues to send back rare data from beyond the solar system. Launched in 1977, Voyager 1 is one of the most important space missions ever undertaken. It was originally sent to study the outer planets, including Jupiter and Saturn, but it went far beyond its initial goal. Today, it is the most distant human-made object in space, travelling through interstellar space at high speed. Its role has evolved. Currently, Voyager 1 serves as an asset for scientists to learn more about interstellar space conditions and the heliosphere, the area where the Sun has no influence. Together with its sister spacecraft, Voyager 2, it is the only probe that can deliver direct information from this previously unstudied region. The primary motivation for turning off the instrument suite was quite obvious. Voyager 1 had run out of power to operate all of its systems. The spacecraft is equipped with a radioisotope thermoelectric generator that utilises the heat generated by decaying plutonium and transforms it into electric power. The energy level, however, has declined gradually since the probes were launched; about 4 watts disappear every year. Without such steps, Voyager 1 risks triggering an automatic fault protection system that could shut down multiple components at once, making recovery far more difficult. The instrument that was powered down is known as the low-energy charged particles experiment (LECP). It has been operating almost continuously since Voyager 1 was launched in 1977. Over the years, the LECP has studied ions, electrons, and cosmic rays from both the solar system and interstellar space. It has helped scientists understand the region beyond the heliosphere, including detecting pressure waves and changes in particle density. Despite its importance, shutting it down became necessary to preserve the mission. “While shutting down a science instrument is not anybody’s preference, it is the best option available,” Kareem Badaruddin, Voyager mission manager, was quoted as saying by Nasa . “Voyager 1 still has two remaining operating science instruments—one that listens to plasma waves and one that measures magnetic fields. They are still working great, sending back data from a region of space no other human-made craft has ever explored. The team remains focused on keeping both Voyagers going for as long as possible.” This shutdown was not sudden. Scientists had already created a long-term plan to switch off instruments in stages as power levels dropped. Originally, each Voyager spacecraft carried 10 instruments, but most have already been turned off over time. The LECP was next in line. A similar step was taken for Voyager 2 in 2025. Communication delays also add to the challenge. Voyager 1 is now more than 15 billion miles from Earth, meaning it takes about 23 hours for commands to reach the spacecraft. The shutdown process takes a few more hours to complete. Even after this shutdown, Voyager 1 continues to operate and send back valuable scientific data. Two instruments remain active, allowing scientists to study plasma waves and magnetic fields in interstellar space. Interestingly, a small part of the LECP system has been left running because it uses very little power. This keeps open the possibility that the instrument could be restarted in the future if enough energy becomes available. Engineers are working on a more advanced strategy to stretch the spacecraft’s remaining power. This plan, informally called the “Big Bang”, involves replacing power-hungry components with more efficient alternatives. The approach will first be tested on Voyager 2, which has slightly more available power and is closer to Earth. If successful, it could later be applied to Voyager 1. If everything works as hoped, the latest shutdown could extend Voyager 1’s operation by at least one year and possibly even allow future revival of some systems.