EEVblog 1547 (Part 2) - PINGing the Voyager 2 Space Probe!

[@CuriousMarc]

Fantastic to see the real details of the space comm! Thanks for the video! You'd think 20W from that far away would be a lot more challenging to receive. I'm surprised at how easy it is for them to pick up the signal. Now of course the bit rate is 160 bits per second, but with 10 dB SNR they must have a pretty low bit error rate. What a communications achievement from such an old spacecraft!

[@RALL123456]

Love your series on apollo comms too!! 👏👏👏

[@liam3284]

20 Watts is 43dBm. Then Voyager 2 has a 36dBi antenna gain, so we are up at +79dBm already. The dish itself likely has 60dB of gain, if not more.

[@MichaelCowden]

OMG Dave, this is absolutely some of the coolest stuff I have ever seen. I'm not an electronics or RF engineer, just an IT engineer and an amateur radio operator, so I understand all these concepts and all the reasoning and science, and it just blows my mind the figures being discussed. This is an awesome set of videos. Thank you to CDSCC and you for all the access and work required to share this video with the world. I'm just awestruck. Jealous of your access. Cheers mate!

[@MichaelCowden]

And Dave, I live nearby the Pisgah Astronomical Research Institute, which used to be a NASA deep space communications facility, so this is like a modern extension of what they used to use years ago. So awesome.

[@GadgetUK164]

Agreed! This is fascinating! I honestly didnt think they were still in touch with Voyager 2!

[@jrb_sland]

Aging [74] Canadian man here. I was 29 when the two Voyagers launched, and I've been fascinated by their images of the outer planets for all the intervening years. Truly great voyages of discovery. My humble thanks to all the folks who keep in touch with these wonderful spacecraft for their dedicated service to all humanity. God bless you all...

[@Lucky32Luke]

A thing of beauty, a joy forever. This antenna is an engineering marvel. The mechanical and RF accuracy is mind blowing!

[@Diamond_Tiara]

man, that's awesome. you're literally communicating with something outside our solar system, it's going interstellar ! also yeah the antennas are monsters. love that.

[@stevedaenginerd]

How lucky you are to land a tour like this! Thank you so much for sharing with the class!🤓

[@remcolangemaire]

I want him as my teacher, his voice is so calm and he explains everything so clearly

[@MoritzvonSchweinitz]

Great video! I would love more content like this - reputable nerds going to cool places and just getting things shown, without any dumbing down! Pity there wasn't a RF waterfall display showing the blips received by Voyager 2.

[@EEVblog]

I've been invited to Siding Springs observatory.

[@MoritzvonSchweinitz]

@@EEVblog I said "reputable" nerds! 😀 No, but seriously: It could be anything. A power station. A submarine fibre optic landing site. An oil platform. An airport. A traffic control center. A weather station. A factory. Anything, as long as the expert just explains what's going on in a not dumbed-down way, so we can all geek out over it.

[@shazam6274]

@@EEVblog Puh-leez go! And with a camera, of course.

[@tmcgeeau]

Did a double take when Richard was talking about communicating with MER1 as we lost contact in 2018 unfortunately, then remembered it was a re-upload from 2017. Awesome content regardless, cheers!

[@robotheadache]

So fantastic-- been absolutely obsessed with the Voyager craft for the longest time, gone even so far as to try to dig into the DSNNow data to learn more about what this process looks like, so seeing these insights has been an absolute treat!

[@willrobbinson]

this is soo intense been following these beautiful space crafts from the start these space probes still operational! from the LATE seventies technology and still going with coms its just truly amazing , I just love this project i hope communication continues till loss of signal (will be a sad day for us followers) thank you for the tour of work center

[@roger_VK2VRK]

I had the privilege of visiting there a while back, absolutely fascinating place... Richard is a top bloke and very dedicated individual.

[@Zenvalley]

For those curious, the OS seems to be Oracle Solaris 10, or something equivalent.

[@hydraulicsystems332]

The interface on some of the widgets seemed javaish.

[@K3rbalSpace]

@@hydraulicsystems332 Looks like plain-old AWT, and Remember, Sun invented Java

[@AdamJRichardson]

Def looks like Solaris, but couldn't say which version (I left Sun in late 90s...). Cool to see it still going! Am guessing there's legacy code for Voyager that's not worth porting over

[@hallkbrdz]

As a telecommunications engineer, this is fascinating - thanks!

[@onjofilms]

NOP is my favorite command of all time.

[@michaelslee4336]

About time you put up part 2, I can only hold my breath for so long. Thanks heaps Dave.

[@EEVblog]

Breath deeply. Part 3 tomorrow, or linked in shortly if you can't wait.

[@michaelslee4336]

@@EEVblog 👍😃😃😃

[@canabrown4774]

Really neat stuff! Such precision in such a large machine! I'll be in my bunk.

[@chris-tal]

Looks like those telemetry GUI windows might have been made with tcl/tk. They are used at some observatories too. Thanks for the insight Dave!

[@AsciiWolf]

And the operating system seems to be a Solaris with JDE. 🙂

[@johnsmiht7776]

Jeeze, Dave, what a great video. I don't think you can find anything to match it! Just like Part 1. Great stuff and THANK YOU!!!

[@BentConrod]

Feels like I've warped back in time six years!! Looking forward to revisiting the (spare) 400kW klystron when part 3 is uploaded on this channel, that never gets old!

[@T2D.SteveArcs]

This is truly awesome fractions of Hz doppler shift😮 and all from 20w RF output aswel 😮 incredible ... trust Dave to spot the discrepancy in the power 😅 thanks Dave😎

[@frankowalker4662]

Brilliant, Dave. I love the footage of the dish turning too. 👍

[@TheAlchaemist]

AMAZING! Simply amazing! It's great to see the real thing and have it explained. It's also amazing that they can receive from that distance with that SNR and 0 error rate.

[@annaoaulinovna]

you are the best electronic engineering broadcaster.

[@felixbors7546]

Thank you so much, Dave; I have worked on physical layer modems for 30 years (from the first voiceband modems). I enjoyed this so much. Thank you.

[@PS-xc2kb]

One of the best - thanks. A super great example of wireless communications taken to the extremes. Whoever designed the original system must have been super forward looking.

[@Poundy]

far out. Thank you for getting this content - and thanks to the folks who let/made it happen at Tidbinbilla. It's an incredible facility.

[@shazam6274]

Breathtaking! Thank you for this. I hope Shahriar of the Signal Path sees this, I think he would be very interested!

[@der.Schtefan]

I haven't seen "Motif" style user interfaces on Unix workstations in decades! :)

[@liam3284]

reminds me of the BoM many years ago.

[@StealthMode139]

Ty for sharing this, I'm from Florida and saw the Last Saturn v launch Skylab. This peaked my interest in the Voyager Probes. This was science Classroom material in the 1980's cutting edge. Always wondered how you stayed in communication with them. Amazing to see the amount of telemetry and your still receiving. V1 and V2 are like family to us. Ty again FL Crew.

[@TradieTrev]

That's a sick SDR setup!

[@davids8345]

absolutely fascinating, thanks Dave, this was brilliant.

[@McTroyd]

Really cool, Dave. Detail I would have never expected from a typical visit. And I'm never gonna get tired of that time lapse at the end. 👍

[@maulerrw]

Loving these videos Dave. Never realised we 'owned' Voyager 2! Always enjoy getting into the nitty gritty of radio and antennas. Some very cool hardware

[@dinkc64]

Such an amazing experience, thank you Dave!

[@RaveYoda]

So so so cool!! I'm jealous you got to be in the operations room getting such an in person breakdown.

[@chitlitlah]

That's such an enormous and beautiful satellite dish. I bet I could pick up all the cable stations with that baby.

[@ericwood3709]

It looks like they are using Solaris with the Java Desktop Environment. That's wild! Is it also on Sparc hardware?

[@BenHeckHacks]

Is it too late to re-flash the Interstellar Record to be nothing but Rick Astley?

[@sinchrotron]

Wow wow wow! I would not imagine I will ever see that

[@eightsprites]

Got chills when I spotted VGR2 on that monitor. Really cool video.

[@DaveBrown1]

Thanks for the video Dave, brill stuff.

[@markrix]

Hey youtube algorithm, this video is tight 👍👍

[@EEVblog]

Did I miss the memo? What' "tight"?

[@stevedaenginerd]

@@EEVblog The kids say something is “tight” when they want to express how extraordinarily awesome or wonderful it is. 🤓

[@markrix]

Ahhh midnwest American slang? Detroit,mi speak for good. 😂

[@markrix]

And dont get started on why we call the middle east that..

[@samh6761]

to be fair, Richard did mention the tightness of it @9:00 minutes in

[@landspide]

All that gorgeous motif

[@wayneschenk5512]

Love this stuff as you find out it’s way more complicated then you thought.

[@accesser]

This is awesome thank you both

[@catalinalb1722]

By far one of the most interesting videos!! Thanks Dave 👍

[@camk2552]

Wow - thanks for the opportunity to view this site. Very cool RF engineering going on here.

[@loki19842]

Thank you Dave for this Video

[@mzac23]

If you zoom in to the clock on the computer at around 12:17 it looks like this was filmed in 2017?

[@EEVblog]

Correct.

[@rickgreer7203]

For anyone interested, this NASA doc digs fairly deep (but approachable) into the comms for both Voyager 1 and 2, and discusses some of the points from the videos: voyager.gsfc.nasa.gov/Library/DeepCommo_Chapter3--141029.pdf

[@johanneswerner1140]

Thanks, that's good stuff! And then there are also quite involved paper models of NASA and ESA crafts on their respective websites. I had a Cassini dangling over my desk for a few years...

[@douglasmaclean5836]

Dave ! ... just absolutely awesome. Bravo Davido.... Brav-oHhhh !! (yet another Canadian fan)

[@rockpadstudios]

great video - thanks

[@RadioChief52]

This was great content! It has to be a wonderful feeling for these guys to know they are literally controlling the communications link to Voyager II.

[@AttilaTheHun333333]

Fantastic and fascinating. Always wondered how they communicate with Voyager. Wonder how this would have looked a few decades ago.

[@jakubniemczuk]

More vacuum tubes stuff. :v

[@mikaelk3860]

Thank you Dave for the videos! Very interesting!

[@digigarb]

Absolutely awesome to see! Thank you!

[@Dinkleberg96]

This is absolutly marvelous!

[@KINGIBEXX]

Thank you so much for posting this. I've always been curious how they contacted the Voyagers. I thought maybe they had some old green screen CRT computers with manual switches. : )

[@Slikx666]

Thanks Dave, that's been very interesting. 😀👍

[@Gnounz]

You only need one window open. But to make it look more professional and to feel way more cool, always open more windows.

[@electronics.unmessed]

Wow! Great insights for RF engineers!

[@marxman00]

If RF worked like this all physics would be wrong

[@TokkanFX]

Excellent, thanks Dave.

[@RebelMan91]

Thats some great tutor. The language used is difficult but the fractions of Hertz that matter make bog impression!

[@colourist.]

Absolutely fascinating video.

[@timeobserver8220]

This video was incredible!!! Man is love to see a series of videos on each step explained here explaining it in laymen's terms. For example what is a subcarrier and how exactly are the final bits sent to NASA? Dedicated VPN / Interconnect or over the net? UDP or TCP etc. What software is used here for GUI and how is it made? What is a symbol in terms of RF... What is MCD2 encoding and why is it used vs others? Why was something measured in Kelvin etc

[@der.Schtefan]

MCD2 is a en.wikipedia.org/wiki/Convolutional_code a way of Forward Error Correction, putting the main stress on the receiver having to figure out what the most likely symbol set was given a set of received signals. Many newer codes exist, that require more complex hardware. You have to think of this: how do you address data transmission errors with a spacecraft that is so far away, that any retransmission of faulty packets would take days to complete? You spread the information across a huge data stream, package it up, and encode it in a way that you can lose x% of packages, and still reconstruct the whole message. Each package is then encoded in a way that x% of errors can appear in that message before it is considered "lost".

[@theminicooper]

One thing I've been searching for but never found is the sound of Voyager... The actual sound of the transmission!! That would be so amazing to actually hear a spacecraft that is so old and so far away!! Anybody ever came across this?!

[@oriole8789]

Fantastic video, thank you for sharing. May I ask why it took so long to publish it? Was it a case of just not getting around to editing it, or another more nuanced reason? Just curious. Thanks!

[@brospartacus5069]

11:52 *That Capricorn One moment. ;

[@shawnerz98]

It's amazing to think that with a received signal level of -159 (or even -152) dBm, that there still could be enough of a signal to recover a 12+ dBm SNR signal. I guess amplifiers close to 15 deg K, amazing things are possible!

[@georgesampson4714]

The rockets and spacecraft get all the publicity but without infrastructure like this they would be meaningless. If I am correct -159dbm is equal to 0.0000000000000000001259 Watts of RF power received by the antenna. Amazing that not only can we detect a signal so small but that we can make sense of it.

[@rfly-fpv]

9:02 In metric system symbol for hour is "h" not "hr", so wind speed should be "km/h" not "km/hr". But, even if a bit incorrectly, still nice to see that metric system is really used in those systems :D

[@johnpodo]

Canberra Deep Space Communications Complex (CDSCC) is the major player in broadcasting Apollo 11 first landing on lunar and moon walk to the whole world. Legendary facility!

[@kartwood]

Very interesting to hear him talk about “millidegrees” and not minutes and seconds of arc.

[@dalsaki]

Super stuff Dave !

[@poneill65]

Breaking News: -152dBm,... VGER is headed back! Get "the code" ready!!

[@ianuragaggarwal]

Excellent. I was wondering the same few days ago, ping resPonse time of Voyagers. DSN and US will miss Voyagers greatly after they become unreachable 😢😢.

[@BaNNshEy]

-159dBm is insane The average target noise for harmonics caused by passive intermodulation from a 20w Carrier is in the -150s. That means the DL signal is more "quiet" than the unwanted noise that we try to mitigate to be as "quiet" as possible in some systems

[@zounds010]

DSS 43 FTW again, recovering the connection with Voyager 2 this week.

[@bertholtappels1081]

Moving a 8000 ton thing in 100 micro degree steps to receive a signal 16 orders of magnitude smaller than a milliwatt. I’m just trying to comprehend the magnitude.

[@cdh76]

Nice. Enjoyed Part 1. This is supposed to be unlisted?

[@yespeace2000]

Motif GUI? ❤

[@captmulch1]

Nice one!

[@markrix]

This video is tight, ive always wondered what the dish station was like 😘

[@markrix]

A.. Multi-convolutional decoder... Is that why I can't understand half the stuff my wife says?

[@jasonwarbird]

I didn't realize that we have had rovers on mars for 20 years! I mean i knew we had rovers up there but i didn't realize it was all the way back in 2003!

[@FortyTwoAnswerToEverything]

The closest radio telescope near me was Puerto Rico's Arecibo. Thanks to recent hurricanes, they were the last nail in the coffin. I wanted to take a tour there

[@reedreamer9518]

I thought Voyager was intercepted by some Star Trek ship after merging with an alien satellite?

[@brandonzawaski]

This is like ham radio on steroids. It is cool you can still hit the voyager spacecraft.

[@alir3953]

really nice.

[@liam3284]

That ping would have a rather long RTT

[@invisiblekincajou]

I guess it is old video, because Mars Exploration Rovers are both offline now and forever (second went silent in 2018). You can't track them now.

[@EEVblog]

Yes, 6 year old footage.

[@marca9955]

Great video. Even though JPL decodes that it would be good to have more insight into the telemetry.

[@cle4tle]

this is so cool

[@loslosbaby]

0:20: "Nice hat, mate."

[@marxman00]

Thats one big fish they got there

[@xDevscom_EE]

Now here's the question. How much further Voyager need to travel for signal power to go below SNR of the antenna? ;-)

[@chitlitlah]

Well it said the SNR was about 5:1, so wouldn't it need to be about the square root of five times as far to completely disappear?

[@xDevscom_EE]

@@chitlitlah I am sure it's not as simple, and radio waves do not attenuate much in vacuum.

[@liam3284]

distance doubles = 3dB less signal. I guess it has 1 or 2 doublings left. The radioisotope thermoelectric generator might fail before then.

[@hackerbob42069]

I haven't seen a Motif UI in use in decades.

[@winterburan]

Very interesting, unimaginable being able to receive such a weak signal from such a distant distance and in continuous movement and with precise aiming like a laser, can I connect my SDRpaly to that antenna? HAHAHA

[@interstellarsurfer]

Beautiful. 👌

[@nickjohnson410]

When you consider that 50% of the human population is of below average intelligence on an individual level, and in aggregate we demonstrate even lower cognizance, it is astounding that certain groups of people were able to achieve levels of engineering and science on a scale like this.