Aging Voyager 1 Sends Back Response After 'Poke' Signal From Earth (cnn.com) 30
"Engineers have sent a 'poke' to the Voyager 1 probe," reports CNN, "and received a potentially encouraging response..."
"A new signal recently received from the spacecraft suggests that the NASA mission team may be making progress in its quest to understand what Voyager 1 is experiencing..." [T]hey hope to fix a communication issue with the aging spacecraft that has persisted for five months. Launched in 1977, Voyager 1 and its twin, Voyager 2, are venturing through uncharted cosmic territory along the outer reaches of the solar system. While Voyager 1 has continued to relay a steady radio signal to its mission control team on Earth, that signal has not carried any usable data since November, which has pointed to an issue with one of the spacecraft's three onboard computers...
On March 3, the team noticed that activity from one part of the flight data system stood out from the rest of the garbled data. While the signal wasn't in the format the Voyager team is used to when the flight data system is functioning as expected, an engineer with NASA's Deep Space Network was able to decode it... The decoded signal included a readout of the entire flight data system's memory, according to an update NASA shared.
"The (flight data system) memory includes its code, or instructions for what to do, as well as variables, or values used in the code that can change based on commands or the spacecraft's status," according to a NASA blog post. "It also contains science or engineering data for downlink. The team will compare this readout to the one that came down before the issue arose and look for discrepancies in the code and the variables to potentially find the source of the ongoing issue."
"The source of the issue appears to be with one of three onboard computers, the flight data subsystem (FDS), which is responsible for packaging the science and engineering data before it's sent to Earth," according to NASA's statement.
CNN reminds readers that Voyager 1 "is currently the farthest spacecraft from Earth at about 15 billion miles (24 billion kilometers) away." Both Voyager 1 and Voyager 2 are now in interstellar space.
Thanks to Slashdot reader Thelasko for sharing the news.
"A new signal recently received from the spacecraft suggests that the NASA mission team may be making progress in its quest to understand what Voyager 1 is experiencing..." [T]hey hope to fix a communication issue with the aging spacecraft that has persisted for five months. Launched in 1977, Voyager 1 and its twin, Voyager 2, are venturing through uncharted cosmic territory along the outer reaches of the solar system. While Voyager 1 has continued to relay a steady radio signal to its mission control team on Earth, that signal has not carried any usable data since November, which has pointed to an issue with one of the spacecraft's three onboard computers...
On March 3, the team noticed that activity from one part of the flight data system stood out from the rest of the garbled data. While the signal wasn't in the format the Voyager team is used to when the flight data system is functioning as expected, an engineer with NASA's Deep Space Network was able to decode it... The decoded signal included a readout of the entire flight data system's memory, according to an update NASA shared.
"The (flight data system) memory includes its code, or instructions for what to do, as well as variables, or values used in the code that can change based on commands or the spacecraft's status," according to a NASA blog post. "It also contains science or engineering data for downlink. The team will compare this readout to the one that came down before the issue arose and look for discrepancies in the code and the variables to potentially find the source of the ongoing issue."
"The source of the issue appears to be with one of three onboard computers, the flight data subsystem (FDS), which is responsible for packaging the science and engineering data before it's sent to Earth," according to NASA's statement.
CNN reminds readers that Voyager 1 "is currently the farthest spacecraft from Earth at about 15 billion miles (24 billion kilometers) away." Both Voyager 1 and Voyager 2 are now in interstellar space.
Thanks to Slashdot reader Thelasko for sharing the news.
Poke, you say? (Score:3)
Why not send this to see if it helps:
100 FOR X=0 to 65535
200 POKE X, INT(RND(1) * 256)
300 NEXT X
Re: (Score:3)
Re: (Score:2)
Integer out of range
Re: (Score:2)
That's because they didn't use rust.
Re: (Score:1)
Does rust check for integer overflow?
Can be expensive on some architectures.
(Traditional languages like Visual Basic do, and it costs nothing if done via a hardware trap. But evil C made errors acceptable. The worse thing C did is get people counting from 0 instead of 1, which affects all modern languages.)
Re: (Score:2)
Integer out of range
OK, I give up. Which integer is out of range?
Re: (Score:2)
if RND(1) can return 1, then the poked byte could be 256. But I could be wrong, it's Saturday and my mind's not in code-mode.
Re: (Score:3)
More like:
Obvious suspect... (Score:1)
I bet it's because of Windows installing a new update. ðY
Hopefully they'll trace the issue (Score:4, Interesting)
But will they be able to work around it given it's almost certainly a hardware failure?
And if engineers have this much trouble figuring out issues with a 1970s system with a total of 32k memory, imagine the fun there'll be troubleshooting more modern deep space probes when they start to fail.
Re:Hopefully they'll trace the issue (Score:5, Interesting)
I would bet yes; if the output from the computer is coherent enough to successfully send that dump and it is still capable of accepting an update command, there's likely enough of a computer left to write code around the failure.
Don't underestimate space nerds faced with a challenge like this - getting Voyager 1 back online is something they'd brag about for the remainder of their lives. It'd be like winning an Olympic gold medal, except you'd be in an arguably even more exclusive a club.
Re:Hopefully they'll trace the issue (Score:5, Interesting)
When the Bush Madministration instructed NASA to destroy the Pioneer data tapes to save a minuscule amount of money they instead, at risk of their pensions, handed them to the Planetary Society. The Society found a drive that could read them in a computing museum (literally), restored it, read the tapes, and posted the data on the Internet. This is the reason there is a solution to the Pioneer Anomaly today.
Re:Hopefully they'll trace the issue (Score:5, Interesting)
But will they be able to work around it given it's almost certainly a hardware failure?
And if engineers have this much trouble figuring out issues with a 1970s system with a total of 32k memory, imagine the fun there'll be troubleshooting more modern deep space probes when they start to fail.
The current assumption is that it is a bit-flip due to a cosmic ray.
Someone recently worked out a translation to turn the received garbage back into readable data. They are now trying to figure out where in the system memory the fault lies so that they can send an update to write it back to correct status.
This is made more difficult because of the decades of updates made in response to previous corrections... Patches to patches years apart by different teams attempting to work around problems diagnosed only by symptoms and fixed via trial and error. Nobody is really sure exactly how it all works now.
Re:Hopefully they'll trace the issue (Score:4, Insightful)
The problem is, that system is mostly undocumented now and there may only be bits and pieces of hardware around to poke it. The designers of it are likely very old if they're alive, the original programmers are gone, and like every computer system of the era, it's completely bespoke.
There will be documents around, but it's likely fragmented, incomplete and likely just enough to trigger the memories of those who were creating it back in the day, but not enough to reconstruct how it works 60 years later.
At the same time, there likely wasn't enough room to implement more than a few basic debugging routines (remember code in the day was often debugged by hand-executing every instruction as it was coded. You probably won't have more than the basic ability to dump the core because the software was effectively fully debugged .
Modern day equipment is a lot better in that respect because we've gotten sloppy with storage. So if a process crashes, we can dump the entire process state from RAM into storage and transmit it on the next satellite data burst. Likewise, all the development tools used to program it likely are stored there because why not, giving the ability to send new code and run it if more detailed debugging is needed.
The ability to hot-patch an old system is not guaranteed - the whole Apollo 14 hack was a sheer exercise in working around a system that was not designed to run code from memory and it relied on altering the memory of the system while it ran to alter how the system worked by putting it in a different state.
Plus, modern day space equipment is often based on common architectures - the current chip of choice is still a PowerPC derivative which is still a maintained architecture to this day. Even if it wasn't, it's a popular architecture that we have tons of documentation on it - system architecture manuals and more because it was used in a lot of places. Chances of its documents surviving are far greater than that of a one-off computer system designed to run the few instruments of a long range satellite. Millions of people worked on PowerPC things over the years. A handful on the Voyager 1 computer and software, and likely the number of people who know how it works over the decades is probably well under 100. And the people working on it now probably only learned of it through handed down knowledge, and likely dozens of scripts and programs written and rewritten through the years.
Re: (Score:2)
What makes you think it is undocumented?
I would think that a traditional NASA project like this would have reams of paper docs, of varying quality. And surely they would have all the source code (in assembler, presumably).
Humans (Score:1)
I'll bet you any amount of money, there's be a significant percent of people who say we should leave that probe alone, like it's sentient. That's what drugs and ignorance has done to the planet.
Re: Humans (Score:2)
I'm not saying it has an Alien virus (Score:1)
but it has an alien virus!
Awesome Work (Score:5, Interesting)
I really want to hear a podcast with the engineer who decoded it. Probably a great story.
Re: (Score:2)
I really don't want to hear it, nor any other podcast. We can read more than 10x faster than we can listen.
A potentially encouraging response (Score:2)
Anything beats "Not tonight, dear. I have a headache."
Far, but not far (Score:2)
Re: (Score:1)
Indeed. A fantastic achievement. And only 35042 light hours to go to get to Alpha Centauri, if it is still 4 light years away by then.
Every journey begins with the first step...
Poke 53280,. (Score:1)
Re: (Score:2)