NASA Saves 10 Watts on Voyager 2, Potentially Extending Mission Into 2031

Ten watts may buy Voyager 2 roughly two more years in interstellar space. NASA engineers have reduced the probe’s electrical demand by about that amount, creating a power margin that could keep the mission operating well into 2031. That projected extension is not guaranteed, but it shows how even lightbulb-scale savings now govern the scientific life of a spacecraft launched nearly half a century ago.

NASA’s Jet Propulsion Laboratory completed the power-conservation operation in July. The team calls it the “Big Bang” because engineers simultaneously turned off selected powered devices and substituted lower-power alternatives, while preserving enough heat for the spacecraft to operate. According to NASA’s mission update, the change freed enough electricity to keep Voyager 2’s three active science instruments operating longer than previously expected.

Why 10 watts matters so much

Voyager 2 does not have solar panels. It receives electricity from radioisotope thermoelectric generators, which convert heat from decaying plutonium into electrical power. Their output declines continuously, leaving each Voyager probe with about 4 fewer watts every year.

At that rate, recovering approximately 10 watts offsets more than two years of annual power decline on paper. The actual operating extension depends on spacecraft condition, thermal requirements and future system behavior, which is why 2031 remains an estimate rather than a fixed retirement date. NASA’s narrower confirmed expectation is that the savings should support Voyager 2’s three operating instruments for at least one additional year.

The intervention also avoided a more immediate scientific loss. Without the newly available power, the mission would have needed to turn off another Voyager 2 instrument before the end of 2026. Preserving three instruments matters because the spacecraft is taking measurements in a region that cannot be reproduced by a probe operating near Earth or elsewhere inside the solar system.

Jamie Rankin, a Princeton University space scientist and the mission’s deputy project scientist, described interstellar space as having a different mixture of gas out there and different behaviour from the particles emitted by the sun into the solar system. Additional operating time therefore produces more than mission longevity: It extends the direct record of how particles, fields and plasma behave beyond the sun’s dominant influence.

Power conservation has become a systems problem

The engineering constraint is no longer simply whether an individual instrument can function. The team must balance science equipment, heaters and supporting electrical devices across a shrinking total-power budget. Turning off too much heating could allow critical parts of a probe to become too cold, while preserving excess thermal margin would consume electricity that could otherwise support measurements.

That makes the “Big Bang” a coordinated systems reconfiguration rather than a single switch-off. NASA has confirmed the broad approach removing power from certain devices and replacing their functions with lower-power alternatives but has not published a complete device-by-device account. The important confirmed result is that Voyager 2 remained able to support its three active instruments after the change.

This follows years of progressively tighter energy management. Since 2024, declining output has forced the mission to turn off two science instruments on each Voyager spacecraft. Other instruments had already been retired because they were intended for the probes’ earlier planetary encounters. Each remaining load now competes for power in increments small enough that even half a watt can influence an engineering decision.

Voyager 1 is next

Engineers plan to perform a related power-saving process on Voyager 1, the more distant of the two probes. The team hopes the work can help it continue operating until around 2030, although that date is also a projection. Voyager 1 currently has two operating science instruments after NASA shut down its low-energy charged-particle experiment in April 2026 to create about a year of power margin.

Voyager 2 provided the safer first application because it had slightly more available power and is closer to Earth. Successful operation aboard one probe does not guarantee the same result aboard its twin after decades of separate aging, however. The next consequential milestone will be completing Voyager 1’s reconfiguration and confirming that it can hold the required electrical and thermal margins. At Voyager’s present stage, a few watts can determine whether humanity receives another year or potentially several of direct measurements from interstellar space.

By David Whitaker — Associate editor for AMI’s aerospace and drone systems desk, translating flight systems, aircraft programs, spaceflight, and UAV developments into accessible technical stories.