The Voyager 2 spacecraft’s energy budget keeps dropping by about 4 Watt/year, as the plutonium in its nuclear power source is steadily dropping as the isotope decays. With 4 Watt of power less to use by its systems per year, the decision was made to disable the plasma spectrometer (PLS) instrument. As also noted by the NASA Voyager 2 team on Twitter, this doesn’t leave the spacecraft completely blind to plasma in the interstellar medium as the plasma wave subsystem (PWS) is still active. The PLS was instrumental in determining in 2018 that Voyager 2 had in fact left the heliosphere and entered interstellar space. The PLS on Voyager 1 had already broken down in 1980 and was turned off in 2007.
After saving the Voyager 1 spacecraft the past months from a dud memory chip and switching between increasingly clogged up thrusters, it was now Voyager 2’s turn for a reminder of the relentless march of time and the encroaching end of the Voyager missions. Currently Voyager 2 still has four active instruments, but by the time the power runs out, they’ll both be limping along with a single instrument, probably somewhere in the 2030s if their incredible luck holds.
This incredible feat was enabled both by the hard work and brilliance of the generations of teams behind the two spacecraft, who keep coming up with new tricks to save power, and the simplicity of the radioisotope generators (RTGs) which keep both Voyagers powered and warm even in the depths of interstellar space.






In a Dutch second-had store while on my hacker camp travels this summer, I noticed a small grey box. It was mine for the princely sum of five euros, because while I’d never seen one before I was able to guess exactly what it was. The “Super 2” weighing down my backpack was a UHF converter, a set-top box from before set-top boxes, and dating from the moment around five or six decades ago when that country expanded its TV broadcast network to include the UHF bands. If your TV was VHF it couldn’t receive the new channels, and this box was the answer to connecting your UHF antenna to that old TV.
