Voyager 2 and its twin, Voyager 1, draw electricity from radioisotope thermoelectric generators, which convert heat from decaying plutonium into power. As that plutonium supply diminishes, each spacecraft loses about 4 watts of available power every year. After nearly half a century in space, the Voyagers have very little power to spare, forcing mission controllers to progressively switch off systems and instruments that are no longer essential.
Since 2024, declining power levels have already forced the team to shut down two science instruments on each Voyager spacecraft. Each probe carries 10 instruments, though others had been turned off previously because they were only used during the mission’s planetary encounters. Without further action, engineers would have needed to switch off another instrument aboard Voyager 2 before the end of 2026.
The “Big Bang” maneuver avoided that. Engineers simultaneously shut down certain power-hungry hardware and switched to lower-power alternatives, while ensuring the spacecraft stayed warm enough to continue functioning properly. The newly freed power is expected to keep Voyager 2’s three remaining instruments operating for at least one additional year.
The extension preserves science that cannot be gathered any other way. Voyager 2 is the only spacecraft directly sampling interstellar space beyond the heliosphere at its current position, and no other mission can replicate that work at any budget. Every additional month of operation yields data that is otherwise impossible to collect.
NASA plans to perform the same power-saving swap on Voyager 1, which is currently farther from Earth than Voyager 2. The mission team expects to complete that work in the coming months.
