Voyager 2 is in interstellar space. After 49 years, its power is low, so engineers must choose which instruments to keep on.

Voyager 2 started with 10 instruments. Now, only three are on, measuring particles, the magnetic field, and gas around the spacecraft.

To save power, engineers turned off some devices and used lower-power ones. This will keep the instruments working for one more year.

These savings will keep three instruments working for at least one extra year.

Voyager 2 was launched in 1977 to study the outer planets. It has outlasted its original plan and is now about 13.3 billion miles from Earth.

Voyager 1 entered interstellar space in 2012. The twins are the only spacecraft to leave the solar system.

Every extra year of data from the missions is very valuable.

Voyager 2 uses radioisotope thermoelectric generators, which turn heat into electricity. The heat source weakens over time.

Engineers have been looking for ways to reduce energy consumption. In 2023, they found a hidden source of power to buy more time.

The decisions to be made will require more analysis and caution than before.

Since 2024, the power supply has forced the mission to turn off two science instruments on each spacecraft.

The team plans to apply the same strategy to Voyager 1, which is even farther from Earth. If it succeeds, both spacecraft will keep flying for at least an extra year.

NASA