It’s been 47 years since the twin Voyager spacecraft started their historic mission. Having travelled through interstellar space, farther from Earth than any other human-made objects, their nuclear batteries are depleting — but NASA is taking measures to squeeze as much life out of the aging probes as possible.

Nearly 50 years after they were first launched, Voyager 1 and 2 are still traveling around interstellar space — though they've faced some setbacks over the years. Now, NASA has announced that the twin Voyager spacecraft are losing some of their features in a bid to extend their lifespans in the face of a diminishing power supply.

NASA engineers are turning off two instruments on Voyager 1 and Voyager 2 to ensure these twin spacecraft can continue exploring interstellar space.