Nearly 49 years after its August 1977 launch, Voyager 2 has a new lease on operating life. NASA engineers at the Jet Propulsion Laboratory completed a power-saving reconfiguration this summer, internally nicknamed the "Big Bang," that frees up enough electricity to keep the spacecraft's three remaining science instruments running for at least another year, according to NASA's mission blog.
Voyager 2 runs on plutonium-238 radioisotope generators that lose a small amount of output every year as the fuel decays, forcing controllers to periodically retire instruments and other systems to keep pace. For the latest fix, engineers simultaneously switched off two heaters and an old onboard tape recorder no longer in regular use, replacing their functions with lower-power alternatives. Because the spacecraft's fuel lines would freeze permanently if managed incorrectly, the team ran power and thermal tests in May and June before executing the swap in July, according to JPL.
Voyager 2 is now about 21.3 billion kilometers — roughly 13.25 billion miles, or 142.5 astronomical units — from Earth, in the constellation Pavo, according to EarthSky. Radio signals traveling at light speed take nearly 20 hours to reach the probe and as long to return. Three of its original ten instruments still operate: the magnetometer, the plasma wave subsystem and the cosmic ray subsystem, the last of which had been slated for shutdown before the new power savings bought it a reprieve.
Mission managers say they plan to attempt the same reconfiguration on Voyager 1, which launched shortly after its twin in 1977 but is now farther from Earth, in the coming months. Both spacecraft crossed into interstellar space years ago — Voyager 1 in 2012, Voyager 2 in 2018 — and remain the only human-made objects operating beyond the heliosphere. NASA has cautioned that each command sent to either probe carries some risk, given their age and distance, but engineers say the latest fix meaningfully lowers the odds of an unplanned shutdown before the end of 2026 and keeps the interstellar science flowing a while longer.
