It's the ultimate remote IT service, spanning 24 billion kilometers of space to repair an outdated, battered computer built in the 1970s.
According to Science magazine, NASA recently announced that Voyager 1, one of the first famous probes to reach interstellar space, has once again sent scientific data back to Earth after a 6-month communication hiatus. In November 2023, a damaged chip caused the data sent by Voyager 1 to be incomprehensible, prompting engineers to perform maintenance on the spacecraft. Subsequently, it began transmitting engineering data and on May 17th, engaged in scientific communication with two of the remaining four instruments.
Voyager 1. Image Source: NASA/JPL-CALTECH
American astrophysicist from Princeton University and Deputy Project Scientist of the Voyager mission, Jamie Rankin, said, "This is a nerve-wracking situation." Even after obtaining engineering data, "we are unsure if we can retrieve the scientific data." NASA will attempt to "wake up" two additional instruments on Voyager 1 in the coming weeks.
Voyager 1 and Voyager 2 have faced numerous challenges during their 47-year journey through the outer solar system and beyond, but the communication crisis on Voyager 1 is unprecedented. Physicist from the California Institute of Technology and a 51-year veteran of the Voyager mission, Alan Cummings, stated, "This is the longest period without data."
Before the communication interruption, Voyager 1 was exploring a mysterious new region in interstellar space - possibly a large pressure bubble or an ancient plasma cloud.
Launched in 1977, the Voyager mission captured stunning images of Jupiter's Great Red Spot, volcanic activity on Jupiter's moon Io, and the blue storms in Neptune's atmosphere. After completing its mission, Voyager 1 continued towards the edge of the solar system and left the heliosphere in 2012, becoming the first spacecraft to reach interstellar space. In 2018, its twin spacecraft, Voyager 2, became the second to enter interstellar space.
With only 6 years of power left in its generators, which are fueled by decaying plutonium, mission managers have already shut down 6 of Voyager 1's original instruments.
In November last year, Voyager 1 started transmitting a series of meaningless binary codes. An emergency team of engineers worked to identify the issue, sifting through half a century of code written by engineers, many of whom have retired or passed away.
Ultimately, the emergency team traced the problem to a memory chip storing the codes needed for communication. After careful consideration, engineers reallocated the chip's functions within the computer's remaining memory - first for the engineering data commands, then for the scientific data commands.
In 2020, Voyager 1's magnetometer recorded a sudden spike in magnetic field strength, while its plasma detector measured an increase in plasma density. Similar anomalies had occurred before, but this time, the observations did not return to baseline levels after a few months. Some experts believe this may indicate Voyager 1 has entered a cloud of ancient interstellar plasma, possibly carrying a higher magnetic field ejected from a star or a star-forming region.
Scientists are now eager to know if the two instruments, which have been silent for 6 months, are still recording higher magnetic field strength and plasma density.
The data returned by Voyager 1 is undeniably valuable. Kostas Dialynas, an astrophysicist and collaborator on Voyager 1's High Energy Particle Instrument, said, "It will be decades before a new interstellar science mission can offer another opportunity to embark on such an important and novel research path."
Currently, scientists are celebrating Voyager 1's awakening. "The Voyager mission is traveling through completely unknown territory," Dialynas said. "We do not know what lies ahead."
