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Antique Voyager Technology
Posted by
kdawson
on Sun Sep 02, 2007 03:51 AM
from the spinning-tapes-and-flashing-lights dept.
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.'"
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I've got an old dell they can use... (Score:5, Insightful)
I can still play my atari 2600 games on my xbox.
Re:I've got an old dell they can use... (Score:4, Insightful)
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Re:I've got an old dell they can use... (Score:4, Insightful)
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.
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Re:I've got an old dell they can use... (Score:4, Insightful)
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Re:I've got an old dell they can use... (Score:5, Insightful)
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.
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Re:I've got an old dell they can use... (Score:4, Insightful)
Give me a week and a modern microcontroller and I'll build you one. Someone else can write the driver.
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Re:I've got an old dell they can use... (Score:4, Funny)
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Re:I've got an old dell they can use... (Score:4, Interesting)
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.
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Re:I've got an old dell they can use... (Score:5, Funny)
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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.
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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.
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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
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Re:I've got an old dell they can use... (Score:5, Funny)
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Re:I've got an old dell they can use... (Score:5, Insightful)
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.
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Re: (Score:3, Interesting)
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 cost
Re: (Score:3, Interesting)
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 m
Re:I've got an old dell they can use... (Score:5, Insightful)
They do. First, take a look at
http://voyager.jpl.nasa.gov/mission/weekly-report
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 [nasa.gov]
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).
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Awesome (Score:5, Interesting)
I am very glad that there are still people who monitor and maintain the Voyagers. They deserve it.
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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 seriousl
Re:I've got an old dell they can use... (Score:5, Insightful)
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.
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Re:I've got an old dell they can use... (Score:4, Interesting)
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?
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They have the source code and the architecture (Score:4, Insightful)
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.
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Re:They have the source code and the architecture (Score:5, Insightful)
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.
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It's Alright... (Score:4, Interesting)
I'm sorry... I'm bitter...
32 bits a second (Score:4, Interesting)
(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.
Cost benefit analysis (Score:3, Insightful)
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(The definition of legacy is "something that works".)
The original equipment probabily just works... (Score:5, Insightful)
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.
Relivs of a time... (Score:3, Interesting)
The reason for all that legacy equipment... (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?
Re: (Score:3, Funny)
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...)
Re:The reason for all that legacy equipment... (Score:5, Funny)
Takes an hour for the processor on Voyager to unpack an ICMP message, parse the ping, compose a reply, encapsulate and send it.
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Re:The reason for all that legacy equipment... (Score:4, Interesting)
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."
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I worked on this project (Score:5, Interesting)
Re:I worked on this project (Score:4, Informative)
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.
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outmoded? (Score:3, Insightful)
The voyager sats are some of our most successful missions, i'd challenge anyone to do better then their "out modded" systems.
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The IRS seems to be pretty succesful: they still run their 1960s mainframes [com.com], yet they're still pinching everybody's money. That's one mission everybody would like to see fail...
"Why can't they just" (Score:4, Insightful)
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.
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Re:Useful information? (Score:5, Funny)
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Re:Functional replacement with modern components? (Score:4, Interesting)
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.
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Re:Functional replacement with modern components? (Score:5, Funny)
The same software SCATS
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Re:What about this requires old equipment? (Score:4, Insightful)
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Re:What about this requires old equipment? (Score:4, Insightful)
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.
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Re:it's cheaper, this way. (Score:4, Interesting)
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.
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Re: (Score:3, Informative)
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 equip
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