AkaSci 🛰️

Oops! Earth has temporarily lost contact with the Voyager 2 spacecraft.

A series of planned commands sent to the spacecraft on July 21 inadvertently caused its antenna to get mispointed by 2°. NASA can no longer send commands or receive data from Voyager 2 via the DSN.

Voyager 2 is programmed to reset its orientation periodically to keep its antenna pointing at Earth; the next reset will occur on Oct 15, which should restore communications.

https://blogs.nasa.gov/sunspot/2023/07/28/mission-update-voyager-2-communications-pause/
#Voyager
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Mission Update: Voyager 2 Communications Pause – The Sun Spot

Jul 28, 2023 at 4:58pmWeb
Show threadAkaSci 🛰️Jul 28, 2023

The two Voyager spacecraft have been traveling in space for close to 46 years.
Their power levels have dropped by about 50%, various instruments have been selectively shut off, yet the spacecraft continue to keep on going and going, sending back valuable science data from interstellar space.

Here are the locations and some vital stats on the two Voyager spacecraft, which were launched on Sept 5, 1977 and Aug 20, 1977 resp.

https://voyager.jpl.nasa.gov/mission/status/
https://www.nasa.gov/feature/nasa-s-new-horizons-reaches-a-rare-space-milestone
#Voyager #Space
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Voyager - Mission Status

Show threadAkaSci 🛰️Jul 28, 2023

Of course, this is not the first time the twin Voyager spacecraft have been out of contact with earth. There have been computer glitches and comm. outages before. But nothing NASA engrs. cannot fix.

The longest outage, ~11 months long, was experienced by Voyager 2 in 2020-2021, during upgrades to the 70-m antenna at the DSN site in Canberra, Aus. During this period, commands could not be sent, but data was still received using three 34-m antennas.

https://voyager.jpl.nasa.gov/news/details.php?article_id=121
#Voyager #Space
3/n

Voyager - NASA Contacts Voyager 2 Using Upgraded Deep Space Network Dish

Show threadAkaSci 🛰️Jul 28, 2023

Let's contemplate for a moment that the computing resources on the Voyager spacecraft are from the 1960s, 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).

The custom-designed hardware and (upgraded) software (and most instruments) are 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/
#Voyager #Space #Science #Computers
4/n

Ch6-2

Show threadAkaSci 🛰️Jul 29, 2023

The software size for the Voyager spacecraft was 3K Lines of Code (SLOC) in 1977. I suspect it is assembly SLOC, given the tight constraints on code-space memory size (4K 18-bit words) rather than Fortran, as is indicated in some online sources.

The software was upgraded a few times as mission objectives and operational use cases changed.

See the graph below for the exponential software size evolution across time and missions.

https://www.nasa.gov/pdf/418878main_FSWC_Final_Report.pdf
#Voyager #Space #Software
5/n

Show threadAkaSci 🛰️Jul 29, 2023

The Voyager probes are powered by radioisotope thermoelectric generators (RTGs) which convert heat from decaying plutonium Pu-238 into electricity using thermocouples.
In 46 years, the power level has dropped by 50% to ~225 watts.

Each computer consumes just 1/3 W; the full Flight Data System requires 14 W; comm system uses a 23 W transmitter.

Over time, various instruments have been selectively shut off to conserve power. See below.

https://voyager.jpl.nasa.gov/mission/status/
#Voyager #Space #Software
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Voyager - Mission Status

Show threadAkaSci 🛰️Jul 29, 2023

Note that Voyager 1 is healthy and communicating via NASA Deep Space Network (DSN) stations at Madrid and Goldstone. Voyager 2 is supported only by the Canberra site due to the location of Voyager 2 south of the ecliptic (see post #2 in this thread).

https://eyes.nasa.gov/dsn/dsn.html
#Voyager #Space #Software
7/n

Deep Space Network Now

The real time status of communications with our deep space explorers

Deep Space Network Now
Show threadAkaSci 🛰️Jul 29, 2023

Of course, Voyager 2 will call home in October. But what lies ahead?

The Voyager probes will be unable to keep instruments powered on much beyond the early 2030s, although NASA engineers may find clever ways to keep comms up for longer. By 2035, power levels will drop by another 10%.

The probes will keep traveling in space. In ~40K years, Voyager 1 will pass within 1.6 light-years of star Gliese 445; Voyager 2 will pass 1.7 lys from star Ross 248.

https://www.nasa.gov/feature/goddard/2017/hubble-provides-interstellar-road-map-for-voyagers-galactic-trek

#Voyager #Space
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Hubble Provides Interstellar Road Map for Voyagers’ Galactic Trek

NASA’s two Voyager spacecraft are hurtling through unexplored territory on their road trip beyond our solar system.

NASA
Show threadGJ Groothedde 🇪🇺Jul 30, 2023
@AkaSci If I calculate it right, Voyager I is currently at a distance from earth roughly 0.12% of the distance to Proxima Centauri, right?
Show threadSimonProDJul 29, 2023
@AkaSci 🤗
Show threadKarl FogelJul 28, 2023
@AkaSci Thank you -- that was exactly the reminder I needed at this moment in the day! I will think of this the next time a browser tab crashes :-/.
Show threadBarry GoldmanJul 28, 2023
@AkaSci th 8 track recorder blows my mind!
Show threadMark - Ottawa on Tundra 🇨🇦  Jul 28, 2023
@AkaSci Was planned obsolescence even a thing then? ;)
Show threadC0ppertopJul 28, 2023
@AkaSci thank god Google never built it. It wouldn’t have made it past Jupiter, without being bricked because of obsolescence.
Show threadRoger MooreJul 28, 2023
@AkaSci
My first computer (a TRS-80 CoCo) had 4K of RAM. When we got it, it lacked reliable mass storage- it had unreliable mass storage in the form of an audio tape recorder- but 4K of RAM was little enough that in a pinch it was still feasible to write it down longhand. It's amazing they were able to make a spacecraft function with such meager resources.
Show threadZeh FernandoJul 29, 2023

@VATVSLPR @AkaSci Yes, they even made a documentary about it

https://en.m.wikipedia.org/wiki/Star_Trek:_The_Motion_Picture

Star Trek: The Motion Picture - Wikipedia

Show threadSteve PyneJul 29, 2023
@AkaSci
If we begin the space age with Sputnik in 1957, the Voyager mission has existed for 70% of the entire epoch - and is still functioning. The Voyagers traversed the solar system and passed beyond the heliosphere into the interstellar realm. The grand gesture of contemporary exploration.
Show threadmarcoroboticsJul 29, 2023
@AkaSci they didn't have npm, of course they could fit everything in 4Kb
Show threadJonJul 30, 2023
@AkaSci I hope NASA tries to get a downlink from Pioneer 6/7/8 again at some point. Possible one of them is still functioning.
Show threadMatt PalmerJul 30, 2023
@AkaSci and here I am getting nervous when I reflash my router's firmware. Imagine going down in history as "the person who bricked Voyager"...
Show threadDJ🌞Aug 5, 2023
@AkaSci This was designed to last long, not to sell cheap. ​
Show threadPeter RelphAug 20, 2023
@AkaSci

If Microsoft had designed Voyager it would have to have been the size of a Death Star & would have failed after 12 months & a day.
Show threadSimon CameronJul 28, 2023
@AkaSci go Voyager
Show threadSteven SandovalJul 28, 2023
@AkaSci “A series of planned commands sent to the spacecraft on July 21 inadvertently...” — another successful failure. #voyager #voyager2 #nasa
Show threadAriaflameJul 29, 2023
@baltakatei @AkaSci Let us all hope not to be judged solely on our the mistakes we make but on our actions on the whole. I certainly make mistakes. It's not exactly easy reprogramming at that distance.
Show threadAlexander The 1stJul 29, 2023

@ariaflame @baltakatei @AkaSci Right; if anything, I'm more shocked it doesn't happen more often.

They've essentially been solving the "Program compiles on first try, and runs correctly first try" every time they've been successful.

Show threadOk...so, hear me outJul 29, 2023
@AkaSci are you sure it's still there and not in the Delta quadrant? We have a...habit... of misplacing Voyager spacecrafts.
Show threadDeRochierJul 29, 2023
@AkaSci I just re-watched this documentary last night. The Voyager missions were one of mankind’s most thrilling accomplishments.
Show threadAkaSci 🛰️Jul 29, 2023

@DeRochier
Here is a link to the documentary mentioned above for those who want to watch it - "The Farthest -- Voyager in Space" -
https://www.pbs.org/the-farthest/

#Voyager

Watch The Farthest

None

The Farthest | PBS
Show threadMathias Pohl 🕯️Natenom🕯️Jul 29, 2023
@AkaSci And I always thought software update would be the most important feature of spacecraft software.
Show threadvinceJul 30, 2023

@AkaSci we're all lost in the dark without others hoping to hear from us again

call when you can Voyager, we'll always make the time to catch up 📡

Show thread🇺🇦 haxadecimal 🚫👑Jul 30, 2023
@AkaSci
Bomb#20: "Nevertheless, the order was given."
Show threadMatt PalmerJul 30, 2023

@AkaSci sure, that's what NASA wants you to think. What really happened is that the aliens doing janitorial work on the spacecraft tripped over the ethernet* cable laying across the floor, and it came unplugged.

* Yes, I know that Voyager predates Ethernet.

Show threadOldGuySelfHostingJul 30, 2023
@AkaSci Well that is unfortunate. Glad it has a smart point-home option though. Hopefully it works...
Show threadReiner Jung 🇬🇱 🇺🇦 🇪🇺Aug 1, 2023
@AkaSci who let Mr. Wolowitz near the controls again?