What Voyager 1’s near-death experience says about the future of space exploration

From more than 15 billion miles away, NASA engineers last April began repairing a space probe headed for the constellation Ophiucus, though it won’t reach it for about 38,000 years. NASA launched Voyager 1 in 1977 and has already exceeded expectations, but the space agency hopes to continue receiving data from the probe until at least 2030. However, after Voyager 1 experienced a computer glitch in November, it began transmitting incomprehensible data (which is not entirely unusual for him), prompting NASA to launch those long-distance fixes.

After some uncertainty as to whether any of them would work, the repairs succeeded. Even better, when Salon spoke to NASA about the problem of remotely regulating spacecraft, experts were optimistic about its future and what it says about space exploration in general.

To understand why, it’s first necessary to break down what happened to Voyager 1 in the first place. In November, the spacecraft sent a signal that did not include any data. Engineers realized that the problem was either with the flight data subsystem (FDS) or the telemetry modulation unit (TMU). By the last week of February, NASA sent a “poke” to Voyager 1 to prompt the FDS to send a memory readout with data; not only did this succeed, but NASA soon uploaded a special command that caused Voyager 1 to respond with a full memory read that helped them identify the specific problem with the FDS.

“The team confirmed that the issue is with FDS,” NASA Jet Propulsion Laboratory media relations specialist Calla Cofield told Salon. “A chip responsible for storing 256 words of FDS memory has a stuck bit (the code is stuck at 0 or 1), indicating that the part has failed, either due to age or damage from external particles. This section represents about 3% of the FDS memory The team will have to move the part of the software code stored on the damaged chip.

During the April mission, NASA transmitted a command to Voyager 1 to relocate the portion of the affected FDS software code and redirect references to that code elsewhere in the spacecraft’s software.

“On April 20, the team received engineering data from the spacecraft, indicating that the command was a success,” Cofield said. “All indications suggest that the spacecraft is fine after five months without contact.”

The team once again began receiving science data from Voyager 1 on May 19, and by June all science instruments on Voyager 1 had resumed sending usable data. Even so, Cofield added that “housekeeping [is] still going on with the spacecraft.”

Of course, this is not the end of the matter; Voyager 1 isn’t the only space probe out there that could one day require repairs. There are currently two other space probes that have left the Solar System and remain operational, Voyager 2 and New Horizons. Additionally, NASA has sent two other probes that are now defunct, Pioneer 10 and Pioneer 11. Can the lessons that allowed NASA to repair Voyager 1 be applied to these and other distant spacecraft?

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“The future is less about repairs than about finding ways to solve problems,” said Bob Rasmussen, a member of the Voyager flight team. “We recognize some life-limiting factors and have strategies to preserve fitness as long as possible. However, we cannot predict outright failures, so we must address them as they arise.”

That’s not to say Rasmussen is entirely hopeful about NASA’s ability to salvage malfunctioning probes. In 2019, the agency had to turn off a heater for the Cosmic Ray Subsystem instrument on Voyager 2 to maintain the probe’s power. In April NASA further powered Voyager 2 by tapping into a small reserve energy reservoir used to power the onboard safety mechanism. By doing this, NASA believes it can keep the spacecraft powered by enough liquid that they won’t need to shut down a science instrument until 2026.

Voyager 1 and 2, meanwhile, are always on the brink of a more permanent crash. Even if all their systems work optimally going forward, the spacecraft are still not expected to survive past the 2030s. Either way, the fact that they lasted this long is a testament to the skill and dedication of the 1970s engineers who built them. those. Unfortunately, there may come a day when more than one of their vital systems simply stops working properly.

“The worst case is that both could fail at any time,” Rasmussen said. “Not all failures are recoverable. For many, we would never be able to tell what happened because the contact would simply cease.”

Rasmussen added that the best-case scenario is for Voyager 1 to continue operating for another five to 10 years. “We have a long-term strategy of gradually reducing activities with declining power and using degraded modes of operation,” Rasmussen said. “But we also know what happens to the best-laid plans.”

On a tragic note, June was also the month that Ed Stone, the man who pioneered the Voyager missions and led them for half a century, died. In their obituary for the former director of the Jet Propulsion Laboratory, NASA wrote that Stone was “a pioneer who dared mighty things in space” and “led humanity on a planetary tour of our solar system and beyond, sending NASA where no spacecraft has gone before.”