[Tee tiong huat]

We, engineers with the Deep Space Network were able to find it...Mission Continuity & Challenges
Rather than risk turning the X-band back on be4 determining what triggered fault protection system, team sent a command on Oct. 22 to confirm the S-band transmitter is working. The team is now working to gather info that will help them figure out what happened, return Voyager 1 to normal op. Voyagers 1 & 2 have been flying for more than 47 years, are only 2 spacecraft to operate in interstellar space. Their advanced age has meant an increase in frequency & complexity of technical issues, new challenges for the mission engineering team.
https://scitechdaily.com/15-billion-mile...s-silence/

15 Bil Miles Away, NASA’s Voyager 1 Breaks Its Silence the shutdown & turn on appears to have been triggered by spacecraft’s fault protection system, automatically onboard issues, system try conserves power by disabling non-essential if spacecraft’s power supply is overstretched, it take weeks for team to pinpoint exactly activated the fault protection system. This troubleshooting & Command Response to NASA’s Jet Propulsion Laboratory (JPL) in Southern California manages communications within Voyager 1 via Deep Space Network. When JPL team sends instructions, Voyager 1 responds by transmitting engineering data, helps team assess its reaction to command. This back-&-forth takes 2days— 23 hrs, command to travel over 15 bil miles (24 bil km) to Voyager 1 & another 23 hrs for data to return to Earth.
On Oct 16, flight team sent command to turn on one of spacecraft’s heaters. While Voyager 1 have had ample power to op the heater, so command triggered fault protection system, team learned of issue when Deep Space Network couldn’t detect Voyager 1’s signal on October 18.

Communication Challenges and Solutions help.
Spacecraft typically communicates with Earth using called X-band radio transmitter, named for specific frequency uses, flight team correctly hypothesized fault protection system had lowered rate transmitter, sending back data, mode requires less power from spacecraft, but it changes X-band signal in Deep Space Network needs to listen for. Engineers found signal later that day & Voyager 1 otherwise seemed to be in a stable state, team began investigating what happened. Then, on Oct 19, communication appeared to stop entireling, flight team suspected Voyager 1’s fault protection system was triggered twice, it turned off X-band transmitter switched a 2nd radio transmitter called S-band. S-band uses less power, Voyager 1 had not used communicate with Earth since 1981, uses a different frequency than X-band transmitters signal is significantly fainter, flight team was not certain S-band could be detected at Earth due spacecraft’s distance, but they with Deep Space Network were able to find it.