Voyaging into eternity: Nasa switches thrusters of probe 24 billion km away

After travelling over 47 years in space, Nasa's Voyager 1 spacecraft thrusters have reportedly been clogged with silicon dioxide impairing its communication with earth

Nasa on Tuesday said it had successfully corrected issues with the thrusters of Voyager 1 probe, which is currently in interstellar space and about 24 billion kms from earth. 

The spacecraft uses its thrusters to align its antennas with earth, however, after 47 years of space travel, the space agency said that some of the fuel tubes had become clogged. 

“Engineers working on NASA’s Voyager 1 probe have successfully mitigated an issue with the spacecraft’s thrusters, which keep the distant explorer pointed at Earth so that it can receive commands, send engineering data, and provide the unique science data it is gathering,” the space agency said in a blog published on its website.

 

Launched in 1977 to study Jupiter and Saturn, Voyager 1 crossed into interstellar space in August 2012 and continues to collect and send data back to earth. The spacecraft and its twin Voyager 2, which was launched just 16 days later (reaching interstellar space in 2018), are the only spacecraft to ever travel through the heliosphere, the protective bubble of particles and magnetic fields generated by the Sun.

The two spacecraft are the farthest objects ever to be sent from earth—it currently takes light 22 hours 49 minutes to reach Voyager 1 from earth.

After travelling through space for over 47 years, the Voyagers have all but exhausted their nuclear power source, forcing the engineers at Nasa to execute a rescue plan. It is critical for the space agency to help the probe keep its antennas aligned to earth as it travels through interstellar space to gather data.

The present challenge for the engineers is the fuel tubes in thrusters which are being clogged by chemicals generated from rubber diaphragm in the spacecraft’s fuel tank, impairing their capability to generate force. Now the team has switched Voyager 1 to a different set of thrusters. 

The engineers have been masterfully repurposing its thrusters for decades allowing the spacecraft to sail eternally through space. Voyager 1 is running essential functions only, to help the probe save power as its space journey enters the 50th year. 

What complicates the situation is the distance of the spacecraft, requiring the commands to be sent 24 billion kms across empty space, which takes over 22 hours to reach. 

In June this year, Nasa said Voyager 1 was returning data from all of its four scientific instruments after a glitch in November 2023 had impaired the operations. The four instruments study plasma waves, magnetic fields, and particles.

Where are the Voyagers now?

Voyager 1 and Voyager 2 are the only spacecraft to reach interstellar space, the region outside the heliosphere — the protective bubble of magnetic fields and solar wind created by the Sun. Voyager 1 is escaping the solar system at a speed of about 38,000 miles per hour (with respect to the Sun), 35 degrees out of the ecliptic plane to the north, in the direction of the Solar Apex (the direction of the Sun's motion relative to nearby stars). 

While Voyager 2 is heading for the stars at 34,390 miles per hour, 48 degrees out of the ecliptic plane to the south. The probe is currently at a distance of 20 billion kms from earth.

The Voyagers will eventually pass other stars. Voyager 1 is expected to come within 1.6 light-years (9.3 trillion miles) of AC+79 3888, a star in the constellation of Camelopardalis, in about 40,000 years. 

In about the same time, Voyager 2 will come within 1.7 light-years (9.7 trillion miles) of the vicinity of the star Ross 248, and in about 296,000 years, it will pass 4.3 light-years (25 trillion miles) from Sirius, the brightest star in the sky. 

The Voyagers are expected to eternally wander the Milky Way galaxy.