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   AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:18 JST AkaSci 🛰️

   The venerable Voyager 1 spacecraft is experiencing another glitch. Instead of sending science and engg. data, it is sending a 0101 bit pattern.

   The problem has been narrowed down to the flight data system (FDS), which is not communicating properly with the telecom unit (TMU). A reboot did not help.

   Stay tuned as NASA engrs work out a fix for this 1970's era computer, which has performed magnificently during its long 46-year journey to the planets and to outer space.
   https://blogs.nasa.gov/sunspot/
   1/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:12 JST AkaSci 🛰️

     in reply to

     No new info on the status of the Voyager 1 spacecraft, which since Sep 2023 has been sending a 1010 bit pattern instead of real data.

     Several popular science outfits have been covering it lately. A bit flip in the FDS is suspected, but it is difficult to identify since the memory cannot be read back.

     Several commands were sent yesterday to Voyager 1; responses will arrive 45 hours later tomorrow.

     Wonder why they cannot overwrite all prog and data memory.

     https://arstechnica.com/space/2024/02/humanitys-most-distant-space-probe-jeopardized-by-computer-glitch/
     #Space
     13/n

     GreenSkyOverMe (Monika) and Tim Chambers repeated this.
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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:12 JST AkaSci 🛰️

     in reply to

     Good news from the Voyager 1 spacecraft that has been stuck sending a 0101 pattern since Nov 2023.

     The team has long suspected the root cause to be a corrupted area of memory in the FDS computer. On Mar 1, they sent some commands to make the FDS skip around sections of memory. The data stream rcvd 45 hours later looked different and was decoded to contain a read-out of the entire FDS memory!

     Hopefully, they can now identify and fix the offending memory words.
     🤞
     https://blogs.nasa.gov/sunspot/
     14/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:13 JST AkaSci 🛰️

     in reply to

     • NSFVoyager2

     NASA JPL provided a minor update today about the status of the Voyager 1 spacecraft, indicating that the comm. problem that started more than 2 months ago has not been resolved yet. No other details.

     Please check out the rest of this thread for more info on the problem where instead of sending science and engg. data, Voyager 1 has been stuck sending a 0101 bit pattern.

     @NSFVoyager2
     #Voyager
     12/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:14 JST AkaSci 🛰️

     in reply to

     NASA did not provide a date but it looks like this issue was discovered and acted upon on Dec 7 or 8.

     The graphic below shows the schedule for Voyager 1 comms via DSN, generated on Dec 7. Normally, the downlink rate is 160 bps. On Dec 8, it was switched to 40 bps. And again on Dec 10. Some special commands for the FDS were also sent.
     Since then, the D/L rate has been switched between 160 bps and 40 bps a few times with additional FDS commands uploaded.

     https://voyager.jpl.nasa.gov/pdf/sfos2023pdf/23_12_07-23_12_25.sfos.pdf
     #Voyager
     10/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:14 JST AkaSci 🛰️

     in reply to

     Two-way comms happening now between Voyager 1 and NASA DSN Canberra.

     Of course, the results of the uplink commands will arrive 45 hours from now. The data arriving now left Voyager 1 22.5 hours ago.

     Downlink rate is the lower 40 bps rate.
     The DSN schedule for Voyager 1 shown below was modified and published yesterday.

     Here's hoping that Voyager engineers are getting closer to a solution 🤞

     https://eyes.nasa.gov/dsn/dsn.html
     https://voyager.jpl.nasa.gov/pdf/sfos2023pdf/23_12_14-24_01_01.sfos.pdf
     #Voyager
     11/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:15 JST AkaSci 🛰️

     in reply to

     NASA DSN in Goldstone, CA is currently receiving the downlink from Voyager 1 at a reduced rate of 40 bps. No uplink at this moment.

     Apparently, Voyager 1 switched data rate (160 -> 40 bps) & did a full memory read-out of her Attitude and Articulation Control Subsystem, Flight Data Subsystem, and Command Computer Subsystems A&B.
     Transmission time = 6 hours
     Download size = ~108 kBytes

     Here's hoping that the received data is not 0101... 🤞

     https://eyes.nasa.gov/dsn/dsn.html
     #Voyager
     8/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:15 JST AkaSci 🛰️

     in reply to

     • Daniel Estévez

     A similar but not identical problem afflicted Voyager 2 in 2010. Received science data (but not engg data?) was garbled.

     The problem was traced to a flipped bit in the program stored in the FDS. A command was sent to flip the bit.

     The issue was diagnosed by downloading a full memory image, which implies that engg data download was working.

     This is probably what was done today with Voyager 1 today. Hopefully, it is a similar problem.

     https://voyager.jpl.nasa.gov/news/details.php?article_id=16
     @destevez
     #Voyager
     9/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:16 JST AkaSci 🛰️

     in reply to

     For those interested in failures and recovery in far away spacecraft, check out this thread in August, when Voyager 2 lost contact with earth due to a mispointed antenna (caused by operator error :mastodon_oops: ).
     https://fosstodon.org/@AkaSci/110831401826701180
     #Voyager
     5/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:16 JST AkaSci 🛰️

     in reply to

     Richard Stephenson of DSN Canberra explains on twitter how NASA verified that the uplink is working.

     They sent a command to Voyager 1 to switch between non-coherent mode and coherent mode transmission.

     In coherent mode, the Transmission clock is derived from the Rx signal instead of from the AUX oscillator. This changes the Tx RF frequency a bit which was detected at the DSN.

     https://science.nasa.gov/learn/basics-of-space-flight/chapter10-1/
     https://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_new.pdf
     #Voyager
     6/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:16 JST AkaSci 🛰️

     in reply to

     In the blog post at https://blogs.nasa.gov/sunspot/, Voyager engineers point out the difficulty in diagnosing problems and crafting solutions for a spacecraft with a signal round-trip-time of almost 2 days and hardware/software developed over 46 years ago using technology long since obsolete.

     "Finding solutions to challenges the probes encounter often entails consulting original, decades-old documents written by engineers who didn’t anticipate the issues that are arising today."

     #Voyager
     7/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:17 JST AkaSci 🛰️

     in reply to

     • NSFVoyager2

     Voyager's computer systems were custom-built using 1960s technology, with clock speeds measured in KHz and RAM in kbytes, running hand-crafted software, crammed into 4K of 18-bit wide plated-wire memory (similar to but better than core mem).

     And yes, it uses digital 8-track tape for storage.

     The custom-designed hardware, (upgraded) software and instruments are mostly still functioning after 46 years in space!

     https://history.nasa.gov/computers/Ch6-2.html
     https://hackaday.com/2018/11/29/interstellar-8-track-the-low-tech-data-recorders-of-voyager/
     @NSFVoyager2
     #Voyager
     3/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:17 JST AkaSci 🛰️

     in reply to

     • Daniel Estévez

     This schematic of the Voyager telecom system shows that the FDS sends data to the comm system over 2 serial interfaces - a low rate 10 b/s interface routed to the S-band transmitter and a variable rate 10 - 115.2 kb/s interface whose bits are sent via X or S band.

     Also, from the 2 diagrams (this post and post #1), the outer coding (Reed-Solomon) is done in software!

     What do you think might cause the data to be stuck not at 0 or 1 but at 0101?

     https://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_new.pdf
     @destevez
     #Voyager
     4/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 14-Mar-2024 20:17:18 JST AkaSci 🛰️

     in reply to

     The two Voyager spacecraft, launched on Sept 5, 1977 and Aug 20, 1977, have been traveling in space for over 46 years.

     Voyager 1 is farther away from earth at 24.3 mil km (22.5 light hours), while V2 is 20.3 mil km away, located below the ecliptic. Both spacecraft are in interstellar space.

     Here are the locations and some vital stats on the two Voyager spacecraft.

     You can follow the real-time status of Voyager at https://voyager.jpl.nasa.gov/mission/status/
     Graphic source: https://www.nasa.gov/solar-system/nasas-new-horizons-reaches-a-rare-space-milestone/
     #Voyager
     2/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 21-Mar-2024 21:26:55 JST AkaSci 🛰️

     in reply to

     • Artem Ignatyev

     @zazoobred
     Yes, Voyager comms has to compensate for Doppler, which can shift the X-Band 8.415 GHz downlink carrier by up to 1.3 MHz. Receiver tracking loops do that.

     Interestingly, Voyager 2, due to a failed tracking-loop capacitor, cannot track uplink signals beyond +-100 Hz offset. So, transmission from earth (at 2.1 GHz) is pre-compensated in frequency, taking earth's rotation, orbital speed and Voyager 2 temperature into account.

     See https://fosstodon.org/@AkaSci/110832414978433970 for some more info.

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     Artem Ignatyev (zazoobred@mstdn.social)'s status on Thursday, 21-Mar-2024 21:27:03 JST Artem Ignatyev

     in reply to

     @AkaSci ahhh, so current location is so that it feels like Earth "chases" it. Thanks.

     Another (probably) simple question: is Doppler effect noticeable with Voyager communications?

     clacke likes this.
     clacke repeated this.
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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 21-Mar-2024 21:27:04 JST AkaSci 🛰️

     in reply to

     • Artem Ignatyev

     @zazoobred
     Voyager 1 is moving away from the Sun at 17 km/s.
     Earth moves around the Sun at ~29.78 km/s.
     Currently, earth's location around the Sun is such that it is moving towards Voyager 1.
     So, the distance between Earth and Voyager 1 is decreasing at slightly less than (29.78 - 17) = 12.78 km/s. Slightly less because Voyager 1 lies above the ecliptic and Earth is not moving at 28.78 km/s directly towards Voyager 1.
     So, the RTT is decreasing by about 3-4 seconds per 12 hours.

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     Artem Ignatyev (zazoobred@mstdn.social)'s status on Thursday, 21-Mar-2024 21:27:05 JST Artem Ignatyev

     in reply to

     @AkaSci couldn't help noticing RTT decreases about 4 secs every 12 hours. I'm curious, why is it so?

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 21-Mar-2024 21:27:06 JST AkaSci 🛰️

     in reply to

     Voyager is not out of the woods yet, but the lesson for all of us is to never ever give up.

     Here is the schedule for comms with Voyager 1 via NASA DSN this weekend. Some new commands will be sent on Friday, with responses expected 45 hours later on Sunday.

     https://voyager.jpl.nasa.gov/pdf/sfos2024pdf/24_03_14-24_04_01.sfos.pdf
     15/n

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     Joel Falcou, Ph. D (joel_falcou@mastodon.social)'s status on Thursday, 21-Mar-2024 21:27:22 JST Joel Falcou, Ph. D

     in reply to

     @AkaSci NASA putting remote back in 'remote debugging' since 1980...

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Monday, 01-Apr-2024 10:12:15 JST AkaSci 🛰️

     in reply to

     • Matt Clifton

     @cliftonmr
     Let's let our reps in Congress know! Congress (republicans really) just cut NASA's budget for FY2025. The (aging) Chandra X-Ray space telescope is slated to be shut down as a result. Others projects will be hit too. JPL went thru some major layoffs last month.

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     Matt Clifton (cliftonmr@en.osm.town)'s status on Monday, 01-Apr-2024 10:12:17 JST Matt Clifton

     in reply to

     @AkaSci It is so fascinating to me that something so far out there can still be troubleshooted and "fixed". I wish NASA had a bigger budget.

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     International Astro Artists (iaaa@spacey.space)'s status on Monday, 01-Apr-2024 10:12:23 JST International Astro Artists

     in reply to

     • NSFVoyager2

     @AkaSci @NSFVoyager2

     How the **** does the tape work at those temperatures?!?!

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Monday, 01-Apr-2024 10:12:27 JST AkaSci 🛰️

     in reply to

     • NSFVoyager2
     • International Astro Artists

     @IAAA @NSFVoyager2
     The Voyager instruments are kept "warm" using heaters and heat from the Radioisotope Thermoelectric Generators (RTG).
     Over time, most heaters have been turned off, as RTG power has dropped, and the remaining instruments are kept at different temps depending on their capabilities.
     Most instruments were designed for -35°C, but some are functioning at much colder temps.
     Hydrazine has to be kept above 1.6°C.
     Have not seen any info on the temp. of the DTR.
     https://voyager.jpl.nasa.gov/news/details.php?article_id=101

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     noodlejetski :verified_gay: (noodlejetski@masto.ai)'s status on Monday, 01-Apr-2024 10:12:32 JST noodlejetski :verified_gay:

     in reply to

     @AkaSci uhhh, aren't the distances supposed to be in billions km, not millions? 150 mil km is 8 light minutes...

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Monday, 01-Apr-2024 10:12:35 JST AkaSci 🛰️

     in reply to

     • noodlejetski :verified_gay:

     @noodlejetski
     Oops! Corrected. Thanks!

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 03-Apr-2024 01:21:40 JST AkaSci 🛰️

     in reply to

     NASA Voyager twitter site confirming that Friday's memory upload was intended as a fix for the Voyager 1 transmission problem caused by the failed memory chip in the FDS computer.

     "Sister @NASAVoyager's reply to Friday's upload should b arriving now @ Goldstone's 70m antenna DSS-14, hopefully confirming that the Flight Data Subsystem memory update was successful. If so, telemetry should now give clearly interpretable signals with science & engineering data!"

     22/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 03-Apr-2024 01:21:40 JST AkaSci 🛰️

     in reply to

     Great news on Voyager 1.
     Richard Stephenson of DSN Canberra reports that engineering data was being received from Voyager 1 last night at 40 bps.

     No science data yet, perhaps because they did not switch to the higher 160 bps rate, but this is a major step towards recovery and validates the diagnosis (failed memory chip in the FDS computer) and fix (rearrange software to bypass the failed memory area).

     Now waiting for a status update from NASA.
     23/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 03-Apr-2024 01:21:41 JST AkaSci 🛰️

     in reply to

     All eyes and ears on Voyager 1 as data is being downloaded from it in response to the "memory upload" commands and data sent 45 hours ago.

     The DSN Goldstone 70m antenna is receiving data now at 40 bits/s.

     Hopefully, the problem with its transmission being stuck at 0101 has been fixed. We will find out this week ...
     🤞

     https://eyes.nasa.gov/dsn/dsn.html
     21/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 03-Apr-2024 01:21:42 JST AkaSci 🛰️

     in reply to

     It's been 6 hours since the "memory upload" data was transmitted to Voyager 1 from the NASA DSN site in Canberra.

     During that time, the signal has traveled about a quarter of the way to Voyager 1, about the average distance to Pluto. The response will arrive at earth on Sunday around 1500 UTC (RTT = 45 hours).

     Let's imagine a spacecraft sent to the nearest star Proxima Centauri, 4.2 light-years away. How would we diagnose problems and upload new software to it?

     https://eyes.nasa.gov/apps/solar-system/#/home
     20/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 03-Apr-2024 01:21:43 JST AkaSci 🛰️

     in reply to

     It looks like the Voyager team is preparing for a new "memory upload" to the FDS computer on Friday, as evident from the DSN schedule and instructions shown below for Voyager 1.

     I am guessing that this is to rearrange the software so that it no longer uses the locations in the faulty memory chip in the FDS. If true, then hopefully we will hear Voyager 1's true voice on Sunday, 45 hours later. OTOH, this may be just one of many steps on the road to recovery.
     🤞
     https://voyager.jpl.nasa.gov/pdf/sfos2024pdf/24_03_28-24_04_15.sfos.pdf
     18/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 03-Apr-2024 01:21:43 JST AkaSci 🛰️

     in reply to

     Looks like the "memory upload" to the Flight Data Subsystem (FDS) on Voyager 1 is taking place at this time from the NASA DSN site in Canberra.
     Go Voyager!

     https://eyes.nasa.gov/dsn/dsn.html
     https://en.wikipedia.org/wiki/Canberra_Deep_Space_Communication_Complex
     19/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 03-Apr-2024 01:21:44 JST AkaSci 🛰️

     in reply to

     Some tech. info on the Voyager FDS computer –
     - There was a backup FDS unit but it failed in 1981.
     - Custom CMOS CPU - 36 instructions. 80 KIPS, 115 kbps data rate.
     - 128 registers, kept in memory.
     - CMOS memory, a first in space, 8KB.
     - No separate memory for program storage vs execution. The CMOS memory is non-volatile kept powered on by the RTG.
     - DMA access to memory by hardware. Instead of “cycle-stealing”, the instructions indicated cycles where DMA can occur.

     https://ntrs.nasa.gov/api/citations/19880069935/downloads/19880069935_Optimized.pdf
     16/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 03-Apr-2024 01:21:44 JST AkaSci 🛰️

     in reply to

     Status update on the Voyager 1 spacecraft which has been sending a 0101 pattern since Nov 2023.

     The problem seems to be a failed memory part in the FDS computer; engineers are planning to move ~200 words of software from one region to another, according to Joseph Westlake, director of NASA’s heliophysics division, who was speaking at a March 20 meeting of the National Academies’ Committee on Solar and Space Physics.

     Westlake sounded very optimistic.
     👍
     https://www.nationalacademies.org/documents/embed/link/LF2255DA3DD1C41C0A42D3BEF0989ACAECE3053A6A9B/file/D727AF88E8C806D7A1F75C8401AF9CF23BCCC2EC9F3A?noSaveAs=1
     17/n

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     The Jack of Sandwich (jack_of_sandwich@mastodon.sdf.org)'s status on Tuesday, 23-Apr-2024 17:39:10 JST The Jack of Sandwich

     in reply to

     @AkaSci Nearly 50 years out there, with no opportunity to provide any direct maintenance, and still operating. Just really amazing work by the people who designed and built the craft.
     And great work to the people at NASA still finding ways to fix problems on a computer so far away, with such low data transfer and so much latency.

     Such a luxury we have on Earth being able to deal with failed hardware by just sending a guy down to the data center to replace it.

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Tuesday, 23-Apr-2024 17:39:15 JST AkaSci 🛰️

     in reply to

     The NASA DSN site in Canberra is currently receiving data from the Voyager 1 spacecraft. The data will ascertain whether the commands sent on Thu to relocate code around the failed memory area in the FDS computer, worked as expected or not.

     Some additional commands are scheduled to be sent today contingent on the results, although the uplink is active now.

     Here's hoping that we get good engineering and science data from Voyager 1 today 🤞

     https://eyes.nasa.gov/dsn/dsn.html
     https://voyager.jpl.nasa.gov/mission/status/
     26/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Tuesday, 23-Apr-2024 17:39:15 JST AkaSci 🛰️

     in reply to

     Hallelujah! And Congrats all around.

     JPL just announced that engineering data was successfully received from the Voyager 1 spacecraft on Saturday April 20, the first time since Nov 2023.

     The commands sent on Thu to relocate some code around the failed memory chip in the FDS worked as expected.

     Science data is not being received yet; it will require relocation of some more code in the sparse free memory areas in the FDS.

     (Engg data = spacecraft health data)
     https://www.jpl.nasa.gov/news/nasas-voyager-1-resumes-sending-engineering-updates-to-earth
     27/n

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     Señor Joe (joevh@mstdn.social)'s status on Tuesday, 23-Apr-2024 17:39:15 JST Señor Joe

     in reply to

     @AkaSci

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Tuesday, 23-Apr-2024 17:39:16 JST AkaSci 🛰️

     in reply to

     Minor update from the NASA Voyager 1 team -

     - Confirmation that the problem is due to a faulty memory chip, which affects about 3% of the FDS memory. We have known about this diagnosis since March 27 but if was not officially announced until today.
     - No info on the recent report that engg data was received last Sunday.
     - "It may take weeks or months" to fix the problem so that Voyager 1 can operate normally without the unusable memory hardware.

     https://blogs.nasa.gov/voyager/2024/04/04/engineers-pinpoint-cause-of-voyager-1-issue-are-working-on-solution/
     24/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Tuesday, 23-Apr-2024 17:39:16 JST AkaSci 🛰️

     in reply to

     The DSN schedule for Voyager 1 next week shows commands to be sent on Tuesday to relocate some FDS code around "VIM5". Presumably, VIM5 is a memory module.

     Additional uploads will take place on Thursday.

     So, there is still work that lies ahead to rearrange the code around the failed memory chip. And we suppose, it has to be done incrementally and meticulously so as to not accidentally brick the FDS computer.

     https://voyager.jpl.nasa.gov/pdf/sfos2024pdf/24_04_04-24_04_22.sfos.pdf
     25/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Tuesday, 23-Apr-2024 17:39:16 JST AkaSci 🛰️

     in reply to

     The Voyager 1 team sent some more commands today to the spacecraft to relocate code around the failed memory area in the FDS computer. The command will reach Voyager 1 tomorrow, 22.5 hours later; we will know the results on Saturday.
     🤞

     The tweet from the Voyager team indicates that the software being relocated is the "program for proper encoding and compression of engineering data (EL-40)."

     Would an analogy of replacing spark plugs on a running car be accurate?
     
     https://voyager.jpl.nasa.gov/pdf/sfos2024pdf/24_04_18-24_05_06.sfos.pdf
     26/n

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     Austin Godber (godber@az.social)'s status on Monday, 20-May-2024 03:51:16 JST Austin Godber

     in reply to

     @AkaSci don’t anthropomorphize the robot, it hates that.

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Monday, 20-May-2024 03:51:17 JST AkaSci 🛰️

     in reply to

     DSN in Canberra should be receiving a full memory read-out of the Voyager 1 FDS computer as we speak. This will help with the planning for further code relocations to enable transmission of science data soon.

     https://eyes.nasa.gov/dsn/dsn.html
     28/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Monday, 20-May-2024 03:51:17 JST AkaSci 🛰️

     in reply to

     Six months after it suffered a serious brain injury and after months of mind-boggling ultra-long-distance surgery, the Voyager 1 spacecraft walked and talked at full data rate today!

     After transmitting a full memory readout on Friday at 40 bps, Voyager 1 switched to the science-mode 160 bps rate, which presumably the DSN site at Goldstone was able to receive and decode today.

     Congrats and kudos to all who made it happen.
     👏 :mastodance:
     https://eyes.nasa.gov/dsn/dsn.html
     29/n

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     Paul (plwt@mstdn.social)'s status on Monday, 20-May-2024 09:41:08 JST Paul

     in reply to

     @AkaSci It continues to be the little spacecraft that could.

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 23-May-2024 08:51:05 JST AkaSci 🛰️

     in reply to

     Voyager 1 is now communicating via the 70m antenna at the NASA DSN site in Madrid, still transmitting at the 160 bps "science mode" rate.

     Steady as she goes!

     https://eyes.nasa.gov/dsn/dsn.html
     31/n

     Joe Ortiz repeated this.
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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 23-May-2024 08:51:05 JST AkaSci 🛰️

     in reply to

     Confirmation today from the Voyager 1 team that the transmission received on Sunday contained science data from 2 of the 4 operating instruments - the plasma wave subsystem and the magnetometer. The other 2 instruments - the cosmic ray subsystem and the low energy charged particle instrument - require recalibration, which will be done in the coming weeks.

     The delicate software operation is working as expected.

     👏 :mastodance:

     https://blogs.nasa.gov/voyager/2024/05/22/voyager-1-resumes-sending-science-data-from-two-instruments/
     #NASA #Voyager
     32/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Thursday, 23-May-2024 08:51:06 JST AkaSci 🛰️

     in reply to

     For those curious about the downlink data rates used by Voyager, it uses 40 bps for engg. data and 160 bps for science data. It requires use of the 70m antenna at the 3 DSN sites. A 1.4 kbps rate is supported with 5 arrayed antennas at Madrid.

     Voyager 1 is 24 billion km away. Tx power = 23W. Rx power = -160 dBm (1e-19 watts). A WiFi signal is > 10 billion times stronger!

     Earlier data rates (kbps) for V2:
     From Jupiter: 115.2
     Saturn: 44.8
     Uranus: 29.9
     Neptune: 21.6

     https://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_new.pdf
     30/n

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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Sunday, 26-May-2024 22:34:28 JST AkaSci 🛰️

     in reply to

     • Hans van Zijst

     @hans
     It's not so much the technology as the distance. Voyager 1 is 24 billion km away. It transmits at 23W. It takes a 70-meter antenna to receive and decode the signal from that distance. Receive power is -160 dBm (1e-19 watts). A WiFi signal is more than 1e10 times stronger!

     As Voyager 1 moves further away, the transmission rate will need to be further reduced.

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     Hans van Zijst (hans@social.woefdram.nl)'s status on Sunday, 26-May-2024 22:34:30 JST Hans van Zijst

     in reply to
     @AkaSci 🛰️ 40 or even 160 BPS 😂
     
     Technology has moved forward really fast since then.
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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Sunday, 16-Jun-2024 11:14:22 JST AkaSci 🛰️

     in reply to

     Here is some info on the various instruments on the two Voyager spacecraft and their current status.

     Note that several instruments have been permanently turned off either because of failures or to save power (power level from the RTGs has dropped over 50% since start-of-mission, over 46 years ago).

     https://voyager.jpl.nasa.gov/mission/status/
     #Voyager1
     33/n

     clacke repeated this.
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     AkaSci 🛰️ (akasci@fosstodon.org)'s status on Sunday, 16-Jun-2024 11:14:22 JST AkaSci 🛰️

     in reply to

     Update on Voyager 1 -
     Voyager 1 is now returning data for the remaining 2 instruments - the cosmic ray subsystem and the low energy charged particle instrument.
     Remaining tasks include resynchronizing the timekeeping software in the 3 onboard computers and maintenance on the digital tape recorder, which is used for storing data from the plasma wave instrument.

     https://science.nasa.gov/missions/voyager-program/voyager-1/voyager-1-returning-science-data-from-all-four-instruments/
     34/n
     #voyager

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