Voyager 2's plasma spectrometer was turned off in a power-saving measure

The Voyager 2 spacecraft's energy budget continues to decline by about 4 W/year, as the plutonium in the nuclear power source steadily declines as the isotopes decay. With a 4 watt reduction in power usage for their systems annually, the decision was made Disable the Plasma Spectrometer (PLS) tool.. like He also pointed out By NASA Voyager 2 Team on Twitter This does not leave the spacecraft completely blind to the plasma in the interstellar medium as the plasma wave subsystem (PWS) is still active. PLS was instrumental in determining that Voyager 2 had indeed left the heliosphere and entered interstellar space in 2018. The PLS system on Voyager 1 had already malfunctioned in 1980 and was decommissioned in 2007.

After rescuing the Voyager 1 spacecraft over the past months from a useless memory chip and swapping between increasingly clogged thrusters, it is now Voyager 2's turn to be reminded of the relentless march of time and the creeping end of Voyager's missions. Currently Voyager 2 still has it Four active toolsbut by the time the power runs out, they'll both be limping along with one instrument, perhaps somewhere in the 2030s if their amazing luck continues.

This incredible feat was made possible by the hard work and brilliance of the generations of teams behind the spacecraft, who continue to invent new power-saving tricks, and the simplicity of the radioisotope generators (RTGs) that keep the spacecraft powered and warm. Even in the depths of interstellar space.