NASA engineers executed a high-stakes power-saving maneuver known as the Big Bang
on the Voyager 2 spacecraft, successfully freeing up energy to extend its science mission by at least another year and avoiding an instrument shutdown before the end of 2026.
Launched in 1977, both Voyager 1 and Voyager 2 are approaching five decades in the harsh vacuum of interstellar space. Their longevity depends entirely on a finite power supply that dwindles with every passing year. Radioisotope thermoelectric generators convert the natural radioactive decay of plutonium into the electricity and heat required to keep the probes functioning in frigid environments.
Because that plutonium supply steadily diminishes, each spacecraft loses approximately 4 watts of available power annually. After nearly fifty years of continuous operation, power margins have shrunk to razor-thin tolerances. Mission controllers have progressively shut down non-essential systems, including instruments originally dedicated to planetary encounters during the grand tour
alignment of Jupiter, Saturn, Uranus, and Neptune.
The Big Bang Maneuver and Why It Was Risky
By 2024, the dwindling power supply forced the mission team to switch off two of the 10 science instruments on each spacecraft. Without an intervention, engineers would have been forced to power down yet another instrument aboard Voyager 2 before the close of 2026. To avert that loss, engineers at NASA’s Jet Propulsion Laboratory devised an audacious operational pivot nicknamed the Big Bang
after concluding that the choice to toggle deeply integrated systems carried no do-overs.
The procedure involved simultaneously turning off certain powered devices—specifically two heaters and an old tape recorder—and substituting them with lower-power alternatives. Managing thermal output is critical because freezing fuel lines would permanently silence the spacecraft.
Rigorous Testing Ahead of the July Success
Before transmitting commands across billions of miles, the team subjected the veteran spacecraft to meticulous testing. According to statements released by NASA, engineers carefully ran power and thermal tests on Voyager 2 in May and June.
Following successful clearance of those tests, the team executed the reconfiguration in July, completing the process by mid-month. The team confirmed that the switch-off command was executed without incident and that the probe is operating normally.
“I don’t want to jinx it, but this ‘big bang’ test has gone remarkably smoothly. Voyager 2—we’re done, and it went exactly to plan. Voyager 1—so far, so good.”
Kareem Badaruddin, Voyager mission manager and systems engineer at NASA’s Jet Propulsion Laboratory
The successful power transfer freed up sufficient energy to keep the three remaining science instruments operating for at least an extra year, pushing back the necessity of shutting down further data collection.
How Voyager 2 and Voyager 1 Differ in Current Status
While Voyager 2 successfully cleared its power hurdle, its twin faces a more precarious situation. Voyager 1 is currently farther from Earth than Voyager 2. In November, Voyager 1 will reach a milestone light day from Earth, requiring a full 24 hours for a one-way radio signal to bridge the distance.
Engineers plan to perform the same Big Bang procedure on Voyager 1 in the coming months, with hopes that the power savings might eventually allow them to restore the disabled particle experiment.
What Lies Ahead as the Probes Approach Fifty Years in Space
The operational survival of both probes remains a testament to the original designers who brimmed fuel tanks just in case mission extensions were ordered.
Both spacecraft will turn 50 years old in 2027, provided their aging nuclear power sources and fuel lines hold out against the frigid conditions of deep space. As the twin spacecraft continue to send back unique scientific data from a boundary beyond the reach of any other operational mission, every watt saved defines the final chapter of humanity’s most distant journey.
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