Voyager 2 power swap Aug. 4

NASA engineers used a tightly choreographed power reconfiguration on Aug. 4 to keep Voyager 2’s last three operating science instruments running longer in interstellar space. The Jet Propulsion Laboratory said the maneuver, nicknamed the “Big Bang,” switched off some powered devices and replaced others with lower-power alternatives while keeping the 1977 spacecraft warm enough to function. The savings should let the probe continue returning data for at least one extra year, NASA said. The agency said Voyager 2 would otherwise have needed to shut down another instrument before the end of 2026. ### What exactly did engineers change on Aug. 4? NASA said the Aug. 4 operation was not a single on-off command but a simultaneous swap of multiple spacecraft functions. JPL described it as turning off certain powered devices and substituting lower-power alternatives, with the added constraint that Voyager 2 still had to stay warm enough to operate in deep space. (jpl.nasa.gov) The “Big Bang” nickname came from the need to do several changes at once rather than step through them slowly. NASA said the maneuver successfully freed up enough electricity to delay the next planned science shutdown on Voyager 2 by at least a year. ### Why is power so tight on Voyager 2 now? Voyager 2 gets its electricity from a radioisotope thermoelectric generator, which converts heat from decaying plutonium into power. (jpl.nasa.gov) NASA said both Voyager spacecraft lose about 4 watts of power each year as that plutonium supply steadily declines. After nearly five decades in flight, the margin between available power and required power has become “razor thin,” according to the agency. March 5, 2025 marked an earlier step in the same conservation campaign. JPL said then that mission engineers had already begun shutting down instruments on both probes to avoid an early end of mission, with three science instruments left operating on each spacecraft after those cuts. ### Which instruments are still on aboard Voyager 2? (jpl.nasa.gov) NASA’s Voyager status page lists three active instruments on Voyager 2: the magnetometer, the plasma wave subsystem and the plasma science instrument’s successor set is not included because that instrument was turned off on Sept. 26, 2024 to save power. The low-energy charged particle instrument was turned off on March 24, 2025, according to the same status page. (jpl.nasa.gov) April 17, 2026 was the latest update on NASA’s public instrument-status page, which shows the remaining Voyager 2 science package focused on measuring magnetic fields and plasma conditions in interstellar space. NASA said in its Aug. 4 update that keeping those three instruments on is the direct result of the new power savings. (science.nasa.gov) ### Where is Voyager 2 in its mission now? Voyager 2 launched in 1977 and became the second human-made spacecraft to enter interstellar space when it crossed the heliosphere boundary in 2018, NASA has said. The probe is the only spacecraft to have flown past Jupiter, Saturn, Uranus and Neptune at close range before continuing outward. (science.nasa.gov) NASA says Voyager 1 and Voyager 2 remain the only spacecraft operating outside the heliosphere, the Sun’s protective bubble of particles and magnetic fields. That leaves Voyager 2 still returning direct measurements from a region no other active mission is sampling. ### Is NASA planning the same fix for Voyager 1? NASA said the mission team plans to carry out the same type of power swap on Voyager 1 in the coming months. (science.nasa.gov) The agency said Voyager 1 is farther from Earth than Voyager 2, making the next operation another test of how long the twin probes can continue science as their power supply declines. (science.nasa.gov) The next public milestone is that Voyager 1 is projected to reach one light-day from Earth on Nov. 18, 2026, according to NASA’s tracking page. Before then, the Voyager team is expected to try the same power-saving reconfiguration that extended Voyager 2’s science mission on Aug. 4. (science.nasa.gov)