In a recent announcement on October 1, NASA made the decision to power down one of Voyager 2’s five remaining instruments in order to conserve the spacecraft’s dwindling power supplies. The plasma science instrument, which was designed to study the Sun’s particle emissions, has been turned off after engineers determined that its usefulness had significantly decreased since Voyager 2 exited the heliosphere in 2018. This decision comes as yet another indication that the Voyager probes may be approaching the end of their historic missions.
Voyager 1 and 2 were launched in 1977 with the goal of traveling farther into deep space than any other human-made object. To keep their systems operational, the spacecraft rely on three radioisotope thermoelectric generators (RTGs) fueled by decaying plutonium-238. However, after 47 years in space, the Voyager probes now operate on only two-thirds of their original power due to the gradual decay of the plutonium fuel.
The plasma science instrument on Voyager 2 consists of four cup-like tools, three of which are pointed towards the Sun to record solar wind while inside the heliosphere. The fourth cup is positioned at a right angle to the others to gather data on planetary magnetospheres, the heliosphere, and interstellar space. Although the instrument played a crucial role in determining Voyager 2’s exit from the heliosphere, its usefulness has diminished over time, with valuable data being collected only once every three months during the spacecraft’s slow rotation.
NASA’s decision to power down the plasma science instrument on Voyager 2 was not taken lightly, as the signal to switch it off had to travel over 12.9 billion miles before reaching the spacecraft. This marks a significant milestone in Voyager 2’s mission, similar to when nonessential instruments were turned off on both Voyager probes after their initial surveys of the solar system’s gas giants in the 1980s.
Despite these adjustments, both Voyager 1 and 2 continue to push the boundaries of exploration, venturing further into deep space than any other man-made objects. With proper maintenance and a bit of luck, the Voyager probes could potentially continue transmitting data from at least one operating instrument well into the 2030s. NASA engineers are working tirelessly to ensure that these iconic spacecraft continue to make history for years to come.
