Engineers at NASA's Jet Propulsion Laboratory have eked out a little more life for instruments aboard the veteran Voyager 2 probe thanks to a power-saving effort called the "Big Bang."

The procedure involved switching several powered devices at once, turning some off and replacing others with lower-power alternatives while keeping the spacecraft warm enough to function. We don't envy whoever had to press the Send button and then wait to discover whether the commands had worked or left Voyager 2 out of action. The procedure appears to have succeeded and, according to NASA, "the savings provide power to keep its instruments operating for at least another year."

Engineers plan to perform the same procedure on Voyager 1 in the coming months. Voyager 1 is farther from Earth than Voyager 2.

In 2027, it will be half a century since the probes were launched, and power is running low. The Radioisotope Thermoelectric Generators (RTG) on both generate electricity by converting heat from decaying plutonium. The probes lose approximately 4 watts of available power each year, which, over half a century, means the spacecraft are running on fumes, electrically speaking.

The spacecraft were built for five-year missions studying Jupiter and Saturn, but Voyager 2 continued to Uranus and Neptune before both probes entered their current interstellar mission. In 2018, one of the original mission scientists, Garry Hunt, told The Register that engineers had brimmed the spacecraft's tanks, just in case an extension was ordered. The longevity of the probes is a tribute to those who designed and built the spacecraft.

Over the years, non-essential systems have been shut down to conserve power. Instruments no longer required following the probes' planetary encounters have long been turned off, and scientists have gradually shut down more of each spacecraft's original ten instruments. Voyager 2 has three instruments still running, and the Big Bang process has pushed back the point where another will need to be switched off, meaning it won't need to be done for at least another year. Without the update, an instrument switch-off would have had to happen before the end of 2026.

Voyager 1 is down to two operating instruments. Its power level dropped unexpectedly during a roll maneuver on February 27, forcing engineers to act quickly – at least as quickly as is possible when commands take more than 23 hours to reach the spacecraft. NASA switched off the Low Energy Charged Particles experiment (LECP) on April 17, but hopes it might be restored after Voyager 1 has its own Big Bang moment.

Voyager 2's LECP was turned off in March 2025. ®