Slashdot Mirror

← Back to Stories (view on slashdot.org)

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.'"

10 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 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.
    3. 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.

    4. 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).

    5. 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
    6. 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.

    7. 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 :)

  2. 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.

  3. 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.