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Antique Voyager Technology

Posted by kdawson on from the spinning-tapes-and-flashing-lights dept.

sea_stuart writes with a story from the Tidbinbilla space tracking station, outside Canberra, Australia. It is still communicating with the two Voyager spacecraft 30 years after they were launched and 18 years after Voyager 2 passed close by Neptune. Here's a little background on Voyager 1 and Voyager 2. "The bank of computers that would look at home in black-and-white episodes of Doctor Who cannot be junked... [T]he 1970s hardware is now our world's only means of chatting with two robot pioneers exploring the solar system's outer limits. Today Voyager 1 is humanity's most remote object, 15.5 billion kilometers from the sun. Voyager 2 is 12.5 billion kilometers from it. Both continue beaming home reports, but now they are space-age antiques. 'The Voyager technology is so outmoded,' said Tidbinbilla's spokesman, Glen Nagle, 'we have had to maintain heritage equipment to talk to them.'"

62 of 293 comments (clear)

  1. I've got an old dell they can use... by DragonTHC · · Score: 5, Insightful

    Is it really that impossible to run these machines inside an emulator on a modern server?

    I can still play my atari 2600 games on my xbox.

    --
    They're using their grammar skills there.
    1. Re:I've got an old dell they can use... by QMalcolm · · Score: 4, Insightful

      This is a total guess, but I'd think that just communicating with something like Voyager 1 would rely on lots of funky old hardware. I mean, the thing is 15 BILLION kilometers away, it's not quite the same as dumping a 2600 cart.

    2. Re:I've got an old dell they can use... by joeava · · Score: 2, Funny

      The problem is in the remote end.

    3. Re:I've got an old dell they can use... by Anonymous Coward · · Score: 4, Insightful

      and yet I don't think it would be a problem for modern software or hardware.
      I think he was thinking more about analog components like amplifiers or something which might be unusual. It's not always all just bits.

      That said, I think the real reason isn't that it's not possible to duplicate with modern technology (it is, of course; anything we could have built then, we can build now), it's just that producing a new system just to communicate with Voyager would probably cost more than maintaining what we've got now. Especially since any new system would likely have unforeseen bugs in it, which could possibly result in loss of communication with the space craft (imagine accidentally sending a command which orders the Voyagers to point their radio antennas away from Earth).

      Still, it's a bit like the ridiculous argument that some day we won't be able to read CD-ROMs, because the technology will have advanced so far, the hardware will no longer exist. Well, yes, maybe. But scientists will always be able to build something that can scan the surface of a CD-ROM, and decode the data there. But it might not be very economical (though I doubt it; a binary infrared laser scanning device is pretty dirt simple). There's a big difference there between what's economically and technologically unfeasible.
    4. Re:I've got an old dell they can use... by Propagandhi · · Score: 2, Interesting

      To keep them humming, Tidbinbilla relies on its most experienced engineers, including John Murray, who will have been working there for 40 years on Monday. His colleague Ian Warren has knotched up 42 years in the space business.

      Not that TFA can be trusted (honestly how would something be "too slow" for a computer? Does my processor get impatient?) but it kinda implies that these guy's primary responsibility is this computer. For the price of two senior engineers it really seems like they could cook up a modern replacement.

      Seems odd that they don't just salvage the analog components and connect it to a modern computer... I guess I'd understand not touching it if it's deemed fragile...

      Anyone know if the Voyagers rely on a heartbeat or something? If it's just a receiver I can't see why building a modern backup isn't worthwhile.
    5. Re:I've got an old dell they can use... by arth1 · · Score: 5, Insightful

      The problem isn't that a new computer can't emulate the software, it's more that it (a) can't do it out of the box and (b) can't emulate the hardware. If you, say, need a 75/1200 baud serial connection to connect to the tranceiver, it doesn't help that USB or Firewire is much faster. And where do you find a 75/1200 serial connector card for a PC? And how's your PC's EBCDIC character set support, for that matter?
      If you have to design both the hardware and the software, it's going to be expensive. Not to say untested. And with the probes being where they are, it's not like you get a second chance if there's a bug. Things have to work perfectly, every time. You'd have a hard time convincing anyone that your emulation would be perfect enough to replace something that's aced the test of time for 25 years.

    6. Re:I've got an old dell they can use... by Zarhan · · Score: 4, Insightful

      Anyone know if the Voyagers rely on a heartbeat or something? If it's just a receiver I can't see why building a modern backup isn't worthwhile.

      They do. First, take a look at

      http://voyager.jpl.nasa.gov/mission/weekly-reports /index.htm

      Namely (of the latest one):

      Voyager 1 command operations consisted of the uplink of a command loss timer reset on 08/04 [DOY 216/0135z] and CCSL A064 on 08/06 [DOY 218/0236z]. The spacecraft received all commands sent and the CCSL was verified.

      Voyager 2 command operations consisted of the uplink of a TLMPRG and a command loss timer reset on 08/06 [DOY 218/1329z]. The spacecraft received all commands sent and the Telemetry Purge proceeded nominally per predicts.

      So yeah, they are still uplinking stuff - mostly just command loss timer resets.

      What happens if they don't send the timer reset? Well, see

      http://voyager.jpl.nasa.gov/science/thirty.html

      If the timer reaches zero, as a result of a command not being received by the spacecraft within the programmed six week duration, the command loss timer will have expired and the Command Loss (CMDLOS) routine will be activated which leads to the initiation of the BML.

      The implementation of BML-7 (the seventh BML to be loaded on-board Voyager 2), in conjunction with the baseline sequence, provides this automated protection against loss of command capability. BML-7, with some differences in implementation for the two spacecraft, is loaded on-board both Voyager 1 and 2.

      So yeah, if receiver on V-ger gets broken, or the transmitter down here on earth, the ship can continue to still send data down here in a completely autonomous fashion. However, a remote capability is probably a good idea to have if something interesting comes up.

      (The link has more details what the "BML" entails).

    7. Re:I've got an old dell they can use... by Ash+Vince · · Score: 3, Interesting

      I studied Space Tech for a while so while this is still a guess I like to think it a fairly educated one:

      In order for something to be acceptable to NASA for use in the space program it has to be very thoroughly tested. This means you could write a software emulator that did everything required, but then it would have to run flawlessly for 10 years in order to be approved for use. You have to remember that these computers can also send commands to the satellites, so if they crash and send an erroneous command out, then that command will be actioned by the satellite.

      I know this is highly unlikely, but it is not impossible so why risk it when the result of that one command could be that we lose both satellites for ever.

      There is a mantra when it comes to dealing with any computer system that is running a mission critical app:

      "If it ain't broke, don't fix it."

      I would suggest that anyone wanting to be sysadmin, learn this. There are times when it doesn't apply but that is usually when the benefit of change out way the risks. In this case what is the benefit of upgrading the system at our end?

      --
      I dont read /. to RTFA, I read /. to offend people in ignorance.
    8. Re:I've got an old dell they can use... by gone_bush · · Score: 5, Funny

      No can do - the licence specifically prohibits running the software in a virtual machine.

      --
      Two roads diverged in a wood, and I - I took the one less travelled by. (Robert Frost, 1916)
    9. Re:I've got an old dell they can use... by mrmeval · · Score: 4, Insightful

      You are stepping into the twilight zone of the military industrial complex/government procurement system.

      An existing system that works has gone through the bowels of this system and been sanctified.

      It would take as much money to re-engineer it as it does to maintain it. It is an annoying fact that getting money to fix something in either the military or government is easier than getting something new even if the new item would save money. This is one of the reasons several of the systems I've worked on were 20+ years old. The anti-mortar Firefinder radar being used in Iraq was designed in the seventies and finally approved and deployed in the 80s and is still in use today.

      There are plans to replace it but right this instant they need them in the field so it costs much more to refurbish one than to buy either a 'newly' made one which is intended for foreign sales and is not authorized for procurement or procure the newest model.

      Currently the latest and greatest is rumbling around the guts of the system and some prototypes were fielded in 1998 so expect them to be finalized in 2008 and accepted later....

      I wish I could point and say "graft and corruption" but it's fighting that which has led to our current procurement system. It's not ever going to be perfect but it does help to keep sawdust out of MREs.

      --
      I'd go on a Vegan diet but the delivery time from Vega is too long. --brownkitty
    10. Re:I've got an old dell they can use... by PetraData · · Score: 2, Insightful

      This assumes that:

      (a) they have the source code
      (b) the source code is not too obfuscated from 1970s engineering paradigms that it can be understood
      (c) the guy who originally wrote the system is not dead so that they can talk to him about all the eccentricities of it
      (d) that it isn't too bulky to cause a slowdown on NASA's emulators when dealing with real time communication
      (e) there is no funky encryption built into the system to protect it from the Soviets

      In terms of cost/benefit analysis, it's probably just cheaper for them to leave the old equipment running than pay millions for consultants to take a look at how to port a 1970s communication system built at the height of the Cold War ... to Windows.

    11. Re:I've got an old dell they can use... by jamesh · · Score: 2, Interesting

      It would take as much money to re-engineer it as it does to maintain it. It is an annoying fact that getting money to fix something in either the military or government is easier than getting something new even if the new item would save money.


      I'm sure you understand why... I think the conversation would go something like this:

      IT: "This new system will cost $1bn, and will save $3bn/year in maintenance on the old system".
      Management: "The previous system was supposed to cost $1bn to develop, and ended up costing $10bn. If I sign off on this it will be my ass on the line when the budget blows out, so I'll stick with known quantities thanks."
    12. Re:I've got an old dell they can use... by Pseudonym · · Score: 3, Insightful

      And where do you find a 75/1200 serial connector card for a PC?

      Give me a week and a modern microcontroller and I'll build you one. Someone else can write the driver.

      --
      sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
    13. Re:I've got an old dell they can use... by Kjella · · Score: 2, Insightful

      So yeah, they are still uplinking stuff - mostly just command loss timer resets.

      And there's the #1 reason not to touch this system already. Both probes have left the solar system and entered interstellar space. There's something like ~70000 years to the next star system. We're not expecting them to find anything, and if they did the direction they're going is probably as good as any. Right now it's just the record for "most distant object we've held communication with", so don't mess with it. Is it seriously that big a problem to keep the system going here on earth when you manage to keep it going in outer space? Ir's not like we need to upgrade it for any reason, it's basicly living its own life together with the Voyager probes, like a small bubble of the 70s. Worst case the hardware completely breaks down with no spares and we have to just listen to it, which is what we do already (I assume we can do that with more modern equipment). So where's the upside of moving to a newer system?

      --
      Live today, because you never know what tomorrow brings
    14. Re:I've got an old dell they can use... by nurb432 · · Score: 2, Insightful

      Ok, so run them in parallel for 10 years. Its not like there is a hurry here.

      And since you seem to hik we cant create 'new', what happens when one of the old ones die and we cant repair it due to its age? At least if we have tried to replicate the functions with modern equipment we have a chance.

      Cost is relative, in this case.

      --
      ---- Booth was a patriot ----
    15. Re:I've got an old dell they can use... by FinestLittleSpace · · Score: 2, Insightful

      I always thought it was the Voyager 'probe', not satellitte. Satellitte suggests 'orbit'.

    16. Re:I've got an old dell they can use... by Lumpy · · Score: 3, Interesting

      a day? cripes! I dont even need to build hardware just a soundcard and a little bit of software, an hour tops.

      This kind of stuff is done daily in ham radio. I build a interface to read the old abandoned weather satellites slow scan TV signal with a soundcard and a connector plug. wrote the app in C in 2 hours and had a picture on screen the next pass.

      I would have been faster if I though to record the last pass's audio and replay it for debugging, but no It took me 30 minutes to find a different bird passing over that I could receive.

      --
      Do not look at laser with remaining good eye.
    17. Re:I've got an old dell they can use... by Megane · · Score: 3, Funny

      Give me a week's vacation in France, and I can probably come back with a dozen old Minitel modems.

      --
      #naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
    18. Re:I've got an old dell they can use... by jafiwam · · Score: 4, Insightful

      If I recall correctly, there are several actual science projects still going on with these two spacecraft, despite most of the instruments not being relevant for the tasks, technicians have found ways to tease extra information out of them.

      First, the heliopause / helioshock transition did not happen the way they thought it did. It was in a different place and had different characteristics. They may still run into that, including vibration and change "bell ringing" of it. And, these things might be the only chance we EVER get to study the interstellar medium directly.

      Second, there are light speed, distances vs. gravitiy issues where the spacecraft are NOT WHERE WE EXPECT THEM TO BE based on the equations we have to calculate for that. In other words, basic, fundamental cosmological questions can be pondered using these things.

      The shame is, that people have been trying to turn them off thinking "we're done" when the cost to operate is a freaking drop in the bucket compared to the colossal waste that is the space shuttle. Put down your trashy science fiction novels for once and read some real papers produced by real science. Then you can get outside your narrow view of what one can "find" out there.

    19. Re:I've got an old dell they can use... by maxwell+demon · · Score: 2, Funny

      Well, just tell GWB that the voyagers might find hidden WMDs out there. That should ensure proper financing. :-)

      --
      The Tao of math: The numbers you can count are not the real numbers.
    20. Re:I've got an old dell they can use... by Mr2cents · · Score: 2, Informative
      After reading further in the wikipedia articles, I found this paragraph:

      On March 31, 2006, the amateur radio operators from AMSAT Germany tracked and received data from Voyager 1 using the 20 m dish at Bochum with a long integration technique. Its data was checked and verified against data from the Deep Space Network station at Madrid, Spain. AMSAT-DL article in German; ARRL article in English. This is believed to be the first such tracking of Voyager. There you have it. That old equipment isn't the only thing that can communicate wit V'ger. Probably just a reporting eager to romantisize a story.
      --
      "It's too bad that stupidity isn't painful." - Anton LaVey
    21. Re:I've got an old dell they can use... by Anonymous Coward · · Score: 2, Interesting

      Nope.

      1) It's not a software receiver, it's hardware
      2) There IS a newer receiver, the Block V, that uses a whole board full of custom ICs and demodulate all the old legacy stuff. I would imagine this is what's really being used at Canberra.
      3) There IS a newer (software based) receiver in the works, but not done yet
      4) The processing load is substantially more than your old Dell can handle (we're talking about finding and demodulating a very, very faint signal that is a few Hz wide in a substantially wider bandwidth)
      5) The interfaces to the analog RF hardware are somewhat unique.
      6) Doing the processing requires a very stable reference clock (I assume your Dell doesn't have a hydrogen maser driving the on-mobo sound card? DSN receivers do.
      7) There are a limited number of people in the world (probably 100) who really understand this stuff well enough to do the emulation, an even more limited number who are not retired, and a good fraction of them are busy working on #3, above.

    22. Re:I've got an old dell they can use... by mazarin5 · · Score: 5, Funny

      Going by the progression of this thread, this seems like an appropriate point to suggest that I can do it in minutes with a tuning fork.

      --
      Fnord.
    23. Re:I've got an old dell they can use... by jlarocco · · Score: 2, Insightful

      It blows my mind that smart people think things have to be "purchased" they do not. build them. you have the specifications. and I bet that someone has a EBCDIC set for linux out there already.

      They *already* built the system. They already have a staff capable of maintaining it and fixing it when it breaks. Building a new one won't let them communicate with the probes any faster.

      So what would be the purpose of building a completely new one?

      It blows my mind that nobody seems to understand upgrading "just because" is a really stupid idea.

      --
      Maybe not
    24. Re:I've got an old dell they can use... by Reaperducer · · Score: 2, Funny

      It blows my mind that nobody seems to understand upgrading "just because" is a really stupid idea.
      It's the Microsoft Mentality (tm).
      --
      -- I'm old enough to have lived through six different meanings of the word "hacker."
    25. Re:I've got an old dell they can use... by wazoox · · Score: 4, Insightful

      This is exactly how broken 78RPMs records are read today, mostly old radio archives. The sound can even be better than actually reading the disk on a real phono :)

    26. Re:I've got an old dell they can use... by paganizer · · Score: 2, Interesting

      this might be a good comparison.
      I worked at bellsouth in '97; 1 of the midrange systems I was responsible for was a freaking ancient magnetic core drum & reel to reel monster that ran the switches that "a critical emergency system" used.
      yes, you could replace the hardware components with something a little more modern, but you would have to be absolutely certain that the replacement component was exactly 100% the same as the legacy hardware, down to once-every-3rd-monday bugs; otherwise you could damage the system.
      why not replace the whole thing? the company that made the system was out of business since the late 70's; no source for the software it was running was available, no complete logic diagram of the workings of the system. maybe it would have been possible, maybe not, but you are talking about a system that had been running without flaw for about 25 years. why replace it?
      to the best of my knowledge, it's still running.

      --
      Why, yes, I AM a Pagan Libertarian.
    27. Re:I've got an old dell they can use... by spaceyhackerlady · · Score: 2, Insightful

      it's going to be expensive. Not to say untested. And with the probes being where they are, it's not like you get a second chance if there's a bug. Things have to work perfectly, every time. You'd have a hard time convincing anyone that your emulation would be perfect enough to replace something that's aced the test of time for 25 years.

      Isn't that always the case? Yes, the system could be rewritten, if there was time and money to do so. Yes, the old hardware could be emulated, as-is, in new hardware. But the old hardware's bugs are known, are understood, and may even have become part of the de facto specification.

      Under the circumstances, I'd nurse the old hardware along too.

      ...laura

  2. It's Alright... by VE3OGG · · Score: 3, Interesting

    Even after being flung across the solar system, I am sure Captain Janeway will find a way to repolarize the deflector dish to emit a warp bubble that combined with future Borg technology and that from Species 4971, some old fashioned ingenuity, a transwarp generator, a friendly if dull-witted Talaxian, a half-human half-Klingon baby, a group of Maquis rebels, a hot-shot pilot who doesn't give a damn for regulations, and a hot Borg in a skin-tight leotard will be able to make it back, and the ship will probably be in better condition then when it left!

    I'm sorry... I'm bitter...

  3. Re:Useful information? by fr4nk · · Score: 3, Informative
    From the Wikipedia article:

    If Voyager 1 is still functioning when it finally passes the heliopause, scientists will get their first direct measurements of the conditions in the interstellar medium.
  4. 32 bits a second by Nymz · · Score: 3, Interesting
    FTA

    That is because the ageing probes can only chat at a sluggish 32 bits a second, far too slow for modern computers.

    (32 bits) x (60 seconds) x (60 minutes) x (24 hours) x (365 days) x (30 years) = (30,274,560,000 bits)
    (30,274,560,000 bits) / (8 bits) / (1024 bytes) / (1024 KiB) / (1024 MiB) = (about 3.5 GiB over 30 years)

    I don't think a modern computer would help, because it's clear that Comcast is seriously throttling their torrent connection.
    1. Re:32 bits a second by tehSpork · · Score: 2, Funny

      The Voyager probes are 15.5 and 12.5 billion kilometers from the sun and Comcast can connect to them, yet still couldn't get a connection out to my house in relative suburbia until a couple years ago?

      I call BS.

  5. Cost benefit analysis by Colin+Smith · · Score: 2, Insightful

    Seems like nobody's done one for the costs of hiring a couple of engineers to reverse engineer or re-implement the protocol...

    --
    Deleted
    1. Re:Cost benefit analysis by arth1 · · Score: 2, Insightful

      More likely, they have done just that, which is exactly why this runs on legacy hardware and software.

      (The definition of legacy is "something that works".)

  6. Re:Functional replacement with modern components? by MichaelSmith · · Score: 3, Interesting

    It must cost a fortune to maintain such old computers

    Not really. As long as you have people who understand the hardware and a supply of old machines for spare parts you should be able to keep things ticking along for decades.

    In my last job we ran the entire Melbourne traffic signal system off PDP 11/84's and 83's. Its a good way to keep your wire wrap skills up to scratch.

    --
    http://michaelsmith.id.au
  7. Its probably the different pots of money question. by Thanster · · Score: 2, Insightful

    In (my experience of) public finances, an expenditure to re implement a protocol would be a capital expense, bring on "careful" scrutiny of the whole programme, and risk all these scientists jobs etc. (with no guarantee of getting the cash) and given that the question being answered is more than an entire career in the making (wall clock wise)......... A maintaince bill for existing equipment gets paid (almost) no questions asked.......

  8. Re:What about this requires old equipment? by Detritus · · Score: 3, Insightful

    The reporter is clueless. It's all a matter of money. It's very expensive to take an old piece of software, written in some obscure language, running on an old machine with a weird architecture, reverse engineer the requirements, rewrite it for a modern machine, and debug and test it thoroughly. You need people who understand the old system and the environment that it ran in. It's usually much cheaper to keep the old hardware running. Plus, many older systems were custom designs, optimized for a particular task, and can still do a better job than more generic modern hardware.

    --
    Mea navis aericumbens anguillis abundat
  9. The original equipment probabily just works... by Anonymous Coward · · Score: 5, Insightful

    Communication with different equipment has been done. http://www.arrl.org/news/stories/2006/04/25/2/

    Proof that it's not a problem to receive and decode. Transmit can't be any harder. But why "upgrade" it if they don't have to? The old equipment probably works just fine, so there is no incentive.

  10. Re:Functional replacement with modern components? by unfunk · · Score: 5, Funny

    The same software SCATS

    That sounds like some pretty shitty software...
  11. Relivs of a time... by Swampash · · Score: 2, Interesting

    ...when NASA inspired me, and the projects in which it was engaged filled me with wonder and curiosity. Nowadays the only thing that amazes me about NASA is the bureaucracy. Well, and the big explosions of course.

  12. Re:What about this requires old equipment? by jamesh · · Score: 3, Insightful

    Ok, here is an idea then.. open source. Yes, there are thousands of geeks out there who, if the protocol was simply published, would write that software for the pure pleasure of it.

    Failing that, you'd put the software under the DMCA and claim that it was the hd-dvd encryption algorithm. You'd have three different OSS solutions in a week.
  13. The reason for all that legacy equipment... by itsdapead · · Score: 5, Funny

    (ring) (ring) (click) G'day, this is Tidbinbilla, how can we help?

    "Er, Hi, This is Ranesh from Advanced Emulation Solutions... I'm testing the VM you commissioned to replace your legacy communications solution. Thing is, there seems to be an undocumented bug in the command protocol and the remote client has locked up. Could some one pop over and power-cycle the client, please?

    ****???^^^^!!!!

    Hey - take it easy - "no worries" as you guys say - just turn off the power, count to ten and turn it on again!

    $$$$!!!!##### !!!!!

    Er, 15.5 billion kilometers, you say? Look, I know you guys like to boast about the size of Australia, but...

    $$$$ ****ING OUTER SPACE !!!!! MOST DISTANT MAN-MADE ****ING OBJECT !!!!!

    Oh. Shit. I wonderered why the ping time was 24 hours.

    Don't you guys have on-site support?

    --
    In a survey of 100 programmers, 111111 thought that duck-typing was a good idea.
    1. Re:The reason for all that legacy equipment... by Bob+of+Dole · · Score: 2, Funny

      I was gonna do the standard slashdot geekjerk thing and point out what the actual ping would be, but
      12.5 billion kilometers / speed of light is 11.58 hours.
      So 24 hours is just about right! Well done sir.

      (although it's closer to 23 hours...)

      --
      I respond to your sigs
    2. Re:The reason for all that legacy equipment... by MichaelSmith · · Score: 4, Funny

      although it's closer to 23 hours

      Takes an hour for the processor on Voyager to unpack an ICMP message, parse the ping, compose a reply, encapsulate and send it.

      --
      http://michaelsmith.id.au
    3. Re:The reason for all that legacy equipment... by zero_offset · · Score: 3, Interesting

      "Er, Hi, This is Ranesh from Advanced Emulation Solutions..."

      Or more likely:

      "Hello sir, my name is Tom, calling from your Houston of your Texas. With the client we are noticing a problem. Please to do the needful."

      --

      Slashdot quality declines as the number of hot grits posts decreases. - Provolt's Law, Apr-09-2005

  14. They have the source code and the architecture by Qbertino · · Score: 3, Insightful

    The reprogrammed Voyager 2 to send color pictures while it had been en route for 15 years allready. Mind you, they reprogrammed Voyager 2 to send *color pictures* made with a system that was built to make b/w pictures. Using a single digit amount of registers to push single bits around a 30 year old computer that has less oomph than todays cheapest calculators aboard a space probe that is a kazillion-billion miles away is quite a stunt. Let alone updating the OS this way to generate color images.

    I think these guys know what they are doing and if they choose to keep the old equipment running in order to communicate more relyably with the Voyagers, I trust they have perfectly valid reasons for it. And no, an off-the-shelf Dell is most probably not a feasable replacement. No matter how powerfull it is.

    Oh, and by the way: A modern computer would drain voyagers batteries so fast, they'd be dead in a few hours. My old Sharp 1403 H Pocket Computer, built with technology from the early-to-mid 80s runs 200+ hours under full load on a pair of button-cells. I haven't replaced them in 10 years and it still runs on them. I have yet to find a modern handheld computer that can do this.

    --
    We suffer more in our imagination than in reality. - Seneca
    1. Re:They have the source code and the architecture by InvalidError · · Score: 4, Insightful

      Oh, and by the way: A modern computer would drain voyagers batteries so fast, they'd be dead in a few hours. Never mind that Dell's on-site technical support service is currently not offered in extra-solar-system locations.

      Most people here are talking about upgrading the base station on Earth, not the spacecrafts. As someone else pointed out, most of the reason they are sticking with the old system must be quirky analog/RF components, not the bitstreams themselves - the Voyager base-station antenna is a huge dish array that recovers sub-yoctowatt signals from the probes. The analog/RF front-end needed to filter and amplify this signal before it can be decoded by digital equipment must be a very unique piece of analog kit with decades worth of tweaking and refinement poured into it both before and after the launch.

      The digital decoding should be trivial with modern CPUs but the analog parts were most likely tuned to the point of defying modern technology.
    2. Re:They have the source code and the architecture by Lumpy · · Score: 2, Insightful

      The funny part is the TTL power hogs of yesteryore have a better chance of dealing with space radiation than the new stuff. The full 5V swing between logic levels, and some of the older 70's computing that did a full 10V swing from +5 to -5 volts makes the current stuff seem like unstable messes when exposed to radiation. It is probably one of the reasons those great giant science projects from the beginning of the space race still work.

      Granted, we still have some amazing engineers, the two rovers on mars are proof of that.

      I think the funny part is that most people do not realize how incredibly big that voyagers are. 733Kg is HUGE for a space probe. The thing is nearly the size of a City BUS, and it actually has 420Watts of power from it's power source giving it an incredible amount of electrical power on board. the things were massive, but back then a basic computer with less processing power than my watch took up a toolbox, so it makes sense.

      honestly I am sad that they havent done any follow up deep space probes with an ion engine to get them going on insanely fast (compared to the other probes) trip on out. it would be cool to see a photo of Pluto or some oort cloud objects.

      --
      Do not look at laser with remaining good eye.
  15. Awesome by KlaymenDK · · Score: 4, Interesting

    Whenever I come across news about the Voyagers, I generally dig deep and read a lot. I am utterly in awe -- of the spacecraft themselves, that they are still functioning, that they are so mind-bogglingly far away, and that humans have created them with the tools of their time. Wow. The link you posted shows in what incredible detail the mission was thought through.

    I am very glad that there are still people who monitor and maintain the Voyagers. They deserve it.

    --
    "Good news, everyone!"
  16. I worked on this project by rimcrazy · · Score: 5, Interesting

    What is little known externally except by those that actually worked on this project is that the radios work at all is amazing. Motorola GEG built the radios in the Voyager spacecraft. Right after launch of both space crafts there was a failure of a critical capacitor that sets the bandwidth of the acquisition loop filter. The net result of that failure was that the signal acquisition of the radios was severely impaired. In order to compensate for this NASA engineers developed an emperical model of the entire spacecraft while it was on it's initial loop around the sun for it's slingshot to Jupiter. Since it was relatively close they could hit the spacecraft with a very large signal thus ensuring acquisition of the transmitted commands. The model consisted of predicting exactly where the front end input LO would be depending upon the temperature of the space craft, the added doppler due to movement, aging of the crystals, etc, etc. Basically anything that could effect the LO was factored in. Once the model was complete, the ground stations would then use and probably still use, this model to predict what the frequency for lockup needs to be. Due to the efforts of the engineers at NASA, they were able to "save" both spacecraft and the mission. And they still work today!!! Pretty amazing.

    --
    "TV, a medium as it is neither rare nor well done." Ernie Kovacs
    1. Re:I worked on this project by rimcrazy · · Score: 3, Informative

      Cassinni is using the same transponders as Voyager. They were "left over" from the original build. The loop caps were replaced. The problem somewhat discussed above is it took FOREVER to qual all of the devices used for the electronics. Once they were finally qualified, they were obsolete. In the case of this specific transponder we (Motorola) actually had to convince TI to restart one of their LSTTL fab lines (for you young whippersnapers you can Google what that is) because we needed some replacement parts and these were qualified and rad-hard so we could not replace them with anything else.

      On the Anti-aging we see it all around where US companies are out-sourcing so much technology and the old farts are all being "right sized" or simply retire. In one sense a deep understand of old technology at some point becomes immaterial (Who needs an SXN7 or an AU25.....google that too!) but if the basic problem solving skills are gone to then we are in deep shit if we ever need to do something ourselves.

      --
      "TV, a medium as it is neither rare nor well done." Ernie Kovacs
  17. outmoded? by timmarhy · · Score: 2, Insightful
    Sounded a lot like penis envy to me. Those engineers in the 70's knew what they were doing, unlike the kids today who breeze past their competency based exams.

    The voyager sats are some of our most successful missions, i'd challenge anyone to do better then their "out modded" systems.

    --
    If you mod me down, I will become more powerful than you can imagine....
    1. Re:outmoded? by Rosco+P.+Coltrane · · Score: 2, Funny

      The voyager sats are some of our most successful missions, i'd challenge anyone to do better then their "out modded" systems.

      The IRS seems to be pretty succesful: they still run their 1960s mainframes, yet they're still pinching everybody's money. That's one mission everybody would like to see fail...

      --
      "A door is what a dog is perpetually on the wrong side of" - Ogden Nash
  18. Re:What about this requires old equipment? by Detritus · · Score: 2, Insightful

    You underestimate how much a clever programmer can do with 4kw (kiloword) on many of these systems. These programs can be very complex and difficult to understand, even with the source code.

    --
    Mea navis aericumbens anguillis abundat
  19. Re:it's cheaper, this way. by MichaelSmith · · Score: 3, Interesting

    Old systems had deterministic timing. No cache, no virtual memory, no bloated-pig operating systems designed by idiots in Redmond.

    A typical mainframe of 30 years ago would have done a lot of batch processing. But it still multi tasked. Only an embedded system would have had deterministic timing. And that is true of today as well.

    I funded a hitch hiking holiday in Tasmania in 1986 by doing small withdrawals in the middle of the night when ATM's couldn't connect to the banking systems because overnight jobs were running.

    --
    http://michaelsmith.id.au
  20. Re:Useful information? by QuickFox · · Score: 5, Funny

    Yes, the science community will be rather surprised when the Voyager spacecraft smash into the huge black sphere with the painted stars.

    --
    Terrorists can't threaten a country's freedom and democracy. Only lawmakers and voters can do that.
  21. "Why can't they just" by DynaSoar · · Score: 3, Insightful

    When someone says "Why don't they just", it usually means they have no idea how it's being done, and is just taking that opportunity to show what they know, even though they have no idea if it's applicable.

    When someone says "Why don't we just", they're probably working on the project and know what they're talking about.

    If they could just, they probably would have justed a long time ago. These are, after all, the people who rebuilt the receiver scheduled to receive the Apollo 11 LEM and EVA transmissions in just 12 hours, after it caught fire 1 day into the mission. It was NASA's call not to use them due to the problem, but they could have done it because they know very well what they're doing and how to do it.

    --
    "I may be synthetic, but I'm not stupid." -- Bishop 341-B
  22. Re:Science for the man on the street by pv2b · · Score: 2, Informative

    Let's assume (assumption number one) they mean the voltage of the received signal in the antenna is 20 billion times weaker than a watch battery.

    Now, a watch battery is approximately 3 volts in voltage, if I recall correctly. 3 / 2e10 == 1.5e-10 V -- so if that's what they meant by signal strength, they're getting a voltage of 150 picovolts somewhere in the antenna.

    P = U^2 / R. If we assume (assumption number two) they've got their antenna matched to 50 Ohm wherever they connect their antenna to their equipment. (1.5e-10)^2 / 50 = 4.5e-22 W == 450 yoctowatts. (That, incidentally, is also how far down the SI prefixes go. :-)

    You wanted to know how many picowatts that is... well, that's 4.5e-10 picowatt -- or -184 dBm. This is probably the power they get in their connector after their antenna.

    Or, in other words, 20 billion times weaker than a hypothetical watch battery that emits a RF signal at 3 Volt transmitting into a 50 ohm antenna. ;-)

    This, of course is assuming that's what they meant. They could have meant something else arbitrarilly entirely.

  23. Re:Pictures by Whiteox · · Score: 2, Informative

    Pic here (from a post above) about half way down the page: http://www.hq.nasa.gov/office/pao/History/computer s/Ch6-2.html

    A 16 bit computer with 128 registers and an 8k memory. Pretty good as in 1977 I was playing Star Trek (simple grid system)on an IBM at uni with 8k. The Voyager was cutting edge at the time.

    --
    Don't be apathetic. Procrastinate!
  24. Re:Photos by FeebleOldMan · · Score: 3, Informative

    I couldn't find any pictures of the Voyager computer banks, but I found these pictures of old computer banks from the Viking era, which is about a year or two before the Voyager program. The Voyager computer banks would probably look something like this.

  25. Re:it's cheaper, this way. by MichaelSmith · · Score: 2

    wouldn't it post your withdrawal at a later time, though? In fact, you could get out more money than you had in your account, but the next business day they would slap you with the overdraft charges which hurt (unless your trip to Tasmania is one-way, that is).

    At the time I was completely out of money but I had a separation cheque (remember them?) from my previous employer which I wouldn't be able to cash until the end of the holliday. The account went into debt but I paid it back around the time the bank caught up with my balance.

    Remember that this was in the days when the banks were geared to resolve transactions within a week or two, as opposed to seconds now.

    --
    http://michaelsmith.id.au
  26. "News for Nerds"? by chris_sawtell · · Score: 2, Interesting
    If /. really was "News for Nerds", it would tell us exactly what 35 year old equipment is still working.

    It doesn't. Therefore /. must have made it into the "Mainstream Media" cabal.:-)
    I don't know whether I should celebrate or commiserate. I fear the latter.

    Anyway, anybody know what comps. etc are being used at the Tidbinbilla space tracking station?br I'm old enough to be genuinely interested.