Two old explorers, fading power
NASA's Voyager 1 and Voyager 2 have explored space for nearly 50 years. Launched in 1977, both probes now travel through interstellar space, far beyond the Sun's protective bubble. But their nuclear power sources are aging. Every year, the spacecraft generate less electricity, and engineers must decide which instruments to keep alive.
Voyager 1 is about 169.8 astronomical units from Earth. Voyager 2 is roughly 143.1 AU away. No other human-made object has operated in this region.
The Big Bang maneuver
In April, engineers at NASA's Jet Propulsion Laboratory shut down an instrument on Voyager 1 called the Low-energy Charged Particles experiment, or LECP. That move buys about a year of power. It also buys time for a bigger fix.
The fix is nicknamed 'the Big Bang.' The idea is to swap a group of powered devices all at once. Some devices will be turned off. Others will be replaced with lower-power alternatives. The goal is to keep the spacecraft warm enough to continue gathering science data.
The team will test the Big Bang on Voyager 2 first. Voyager 2 has a little more power to spare and is closer to Earth, which makes it the safer test subject. Tests are planned for May and June 2026. If they go well, engineers will try the same fix on Voyager 1 no sooner than July. If it works, there is a chance Voyager 1's LECP could be switched back on.
A chance at the 2030s
Engineers believe the power plan could keep at least one science instrument running into the early 2030s. They are careful to note that the Voyagers have weathered deep space for 47 years and that unforeseen problems could shorten that timeline.
'Every minute of every day, the Voyagers explore a region where no spacecraft has gone before,' said Linda Spilker, Voyager project scientist at JPL. 'That also means every day could be our last. But that day could also bring another interstellar revelation.'
If the probes stay healthy, Voyager 1 could reach 200 astronomical units from Earth around 2035. Engineers say that will take good luck, good fortune, and good engineering.