She’s alive! NASA has restored contact with Voyager 1 using a transmitter it hasn’t used since 1981.
24.7 billion kilometers from Earth, in interstellar space, the Voyager 1 space probe has scared NASA to death again. But, I repeat, the failure that caused fear of the mission remained just that: fear.
Context. Voyager 1, the ship furthest from Earth after a 47-year journey to the edges of the solar system, remained undetected for about a week, ignoring its engineers with alarming radio silence.
Although NASA responded to the incident cautiously, data from the Deep Space Network showed that Voyager controllers were actively searching for it using antennas in Madrid and Canberra.
Chronology of disappearance. On October 16, the Voyager flight team at NASA’s Jet Propulsion Laboratory (JPL) sent Voyager 1 a command to turn on one of its heaters.
The ship is located 23 light hours from us, so the instructions took almost a day. For the same reason, a response was expected no earlier than October 18. That’s when NASA realized something was wrong: the Deep Space Network antennas were receiving little data, as if the spacecraft was trying to conserve power. And the next day, October 19, he disappeared. The fail-safe system worked.
Automatic shutdown. The sudden loss of communication with Voyager 1 was due to an automatic shutdown of one of the probe’s two X-band radio transmitters, NASA explained in a blog post.
It was likely a fail-safe system that disabled the transmitter, but NASA is still investigating what caused the problem in the first place. One possibility is that non-essential systems were shut down to conserve power after the ship exceeded its meager energy reserves. Which NASA didn’t expect, since Voyager 1’s radioisotope generator still had to have enough plutonium to turn on the heater.
Call home on S-band. As for how they reestablished contact… Voyager never actually stopped calling home. After the X-band transmitter suddenly shut down, he continued to use the S-band transmitter. This radio transmitter requires less power, but has not been used to communicate with Voyager 1 to Earth since 1981.
JPL engineers weren’t sure it would be possible to detect S-band signals, which are different in frequency and weaker than X-band, at that distance. But finally, on October 24, they were able to detect a ship with NASA’s Deep Space Network antennas.
Third rescue in a row. Between November 2023 and May 2024, Voyager 1 stopped sending science data due to memory chip damage. After discovering the problem, NASA engineers were able to move the code to other parts of the spacecraft’s meager memory and restore communications.
Most recently, mission controllers had to restart engines that had been idle for decades to orient the craft. The fuel tubes used by Voyager 1 became clogged due to an aging rubber diaphragm, and the probe was in danger of no longer being able to point its antennas toward Earth.
Voyager 1 refuses to die. And NASA refuses to let him die. Thanks to the persistence of its engineers, NASA reestablished S-band communications with the spacecraft to determine the cause of the problem.
It could be weeks before the team determines what triggered the fail-safe system, but NASA won’t risk turning on the X-band transmitter until it has all the information about what happened.
Images | POT
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