Nearly 50 years ago, two small, identical probes were launched from Florida with a mission to give us our first close-up look at the giants of our solar system.
But as of May 2026, the "Little Spacecraft That Could" are reaching a physical limit that no amount of clever software hacking can fully overcome: they are running out of electricity.
The Nuclear Battery: A Slow Fade
The Voyagers don't have solar panels; at their distance—roughly 164 AU for Voyager 1—the Sun is just a particularly bright star.
The physics here is uncompromising. Every year, the Voyagers lose approximately 4 watts of power due to two factors:
Plutonium Decay: The radioactive source is physically disappearing.
Thermocouple Degradation: The hardware that converts heat to electricity is wearing out.
Launched with 470 watts of power in 1977, the probes are now operating on roughly 230 watts. To put that in perspective, it takes about 200 watts just to keep the radio transmitter running so they can talk to Earth.
The "Big Bang" Hack
NASA engineers at the Jet Propulsion Laboratory (JPL) have spent the last decade in "triage mode," turning off non-essential systems and heaters.
To push back the darkness, NASA is currently testing a maneuver they call the "Big Bang" strategy:
The Plan: In May and June 2026, engineers are reconfiguring Voyager 2’s internal power distribution.
By swapping several aging components for lower-power alternatives and turning off certain fuel-line heaters, they hope to "find" an extra 10 watts of power. The Risk: If the fuel lines freeze, the probes can no longer point their antennas at Earth.
The Rollout: If the test on Voyager 2 succeeds this month, they will apply the same fix to Voyager 1 later this summer.
The Current Scorecard (May 2026)
Here is the status of the remaining science instruments on our interstellar scouts:
| Instrument | Voyager 1 Status | Voyager 2 Status | Function |
| Magnetometer (MAG) | ON | ON | Measures interstellar magnetic fields |
| Plasma Wave (PWS) | ON | ON | Listens for "sounds" of the interstellar gas |
| Cosmic Ray (CRS) | OFF (Feb 2025) | ON | Measures high-energy particles |
| Charged Particles (LECP) | OFF (Apr 2026) | OFF (Mar 2025) | Measures solar wind remnants |
| Plasma Science (PLS) | OFF (2007) | OFF (Sept 2024) | Measures the density of plasma |
How Long Can They Keep Going?
The mission is now a game of inches. With the "Big Bang" power savings, NASA officials are cautiously optimistic that they can keep at least one or two science instruments running on each craft until the late 2020s.
2027: The Voyagers will celebrate their 50th anniversary in space.
This is a major engineering milestone that NASA is desperate to reach while the probes are still "alive." The 2030s: This is the "fingers crossed" zone. By the early 2030s, it is likely that the power will drop below the ~200W threshold required to run the transmitter. At that point, the Voyagers will become silent.
The Silent Legacy: Even after the transmitters die, the Voyagers aren't "gone." They will continue to drift for millions of years. Voyager 1 is currently moving at roughly 38,000 mph.
In about 40,000 years, it will pass within 1.6 light-years of the star AC+79 3888.
The Golden Records—the copper phonograph records containing the sounds and sights of Earth—will likely outlast the human race itself. The probes may be losing power, but as ambassadors, their mission is essentially eternal.