NASA Shuts Down Two Voyager Science Instruments — What It Means For Humanity's Longest-Lived Space Mission

The National Aeronautics and Space Administration (NASA) said on Mar. 5 that it is in the process of turning off two science instruments aboard Voyager 1 and Voyager 2 to extend the life of the farthest-flung human-made objects.

The US space agency, on Feb. 25, turned off the cosmic ray subsystem experiment aboard Voyager 1. It now plans to shut off Voyager 2's low-energy charged particle instrument on Mar. 24.

Through these energy-conserving measures, mission engineers at NASA will keep three instruments on each of these spacecraft operational while taking steps to gradually diminish the power usage on the twin probes.

Both Voyagers were launched in 1977 and lose about 4 watts of power each year, NASA said in a blog. Suzanne Dodd, Voyager project manager at NASA Jet Propulsion Laboratory in Southern California, said that the measure was essential to sustain the mission; without it, they would have only a few months of power remaining.

Both spacecraft were launched into space, carrying 10 identical instruments for various study purposes. Over the decades, as they met their mission objectives, NASA turned off some of the instruments to preserve energy.

The instruments that were kept operational included those that were needed to understand the solar system’s heliosphere and interstellar space. To clarify, the heliosphere is understood as a protective bubble of solar wind and magnetic fields created by the Sun. Meanwhile, interstellar space is the region outside the heliosphere.

Voyager 1 was able to reach the beginning of interstellar space in 2012, while Voyager 2 reached the boundary in 2018 - a feat no other spacecraft has achieved.

The two spacecraft were originally planned to study the outer planets, but they have far surpassed their goals and will hopefully be entering their 50th year of mission in the next two years.

Currently, Voyager 1 is over 25 billion kilometres from Earth, while its twin, in a different direction, is more than 21 billion kilometres away. Due to these vast distances, it takes over 23 hours for a radio signal to reach Voyager 1.