Artist impression of Voyager. Image credit: NASA/JPL

Voyager 2 Update from Dr. Ed Stone

2 Jun , 2010 by

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In early May 2010, the 33-year-old Voyager 2 spacecraft experienced an anomaly where the data it returned to Earth was unreadable. Engineers diagnosed the problem as a flip of a bit in the memory in the flight data system computer that packages data to transmit back to Earth, and were able to successfully reset the computer. On May 23, Voyager 2 sent back data that was again formatted properly, but the teams wanted to check out all the systems on the spacecraft to make sure everything was working properly. We checked in with Dr. Ed Stone, former director of JPL and the project scientist for the Voyager project since 1972 to get the latest news on how Voyager 2’s checkout is progressing.

“The science teams have confirmed that Voyager 2 is again transmitting science data in the expected format and the instruments are fully functional,” Stone said via email. “The only remaining action is to reset the clock in the spacecraft’s data system that lost time while the memory bit was in the wrong state. The reset commands will be sent to the Voyager 2 in the next two weeks.”

The flipped or bad bit in the flight data system was likely caused by a cosmic ray that slipped by the radiation protection on the spacecraft. Since the computer stores information in ones and zeroes, a cosmic ray hit can change the value of a memory bit. The concern was that the flipped bit took place in an important location that could have a serious effect on the spacecraft, but fortunately, the problem was solved “easily.”

I say easily in quotes because of the complexities of diagnosing and fixing a spacecraft at such great distances. Since Voyager 2 is about 13.8 billion kilometers, or 8.6 billion miles, from Earth, it takes nearly 13 hours for signals to reach the spacecraft and nearly 13 hours for signals to come down to NASA’s Deep Space Network on Earth.

Hats off to the scientists and engineers at JPL for their efforts and dedication so we all can continue to follow Voyager’s continuing journey to interstellar space.

Sources: JPL, email exchange with Dr. Ed Stone, Planetary Blog.


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Drunk Vegan
Member
June 2, 2010 6:37 AM

It’s a bit humbling to think that the farthest reaches of our solar system still only involve a 26-hour round trip lightspeed trip. The nearest star, however, is 4.3 light-years away, or about 1581.6 days (one-way) at lightspeed.

And that is only a tiny fraction of the time it takes to travel any significant distance within our galaxy, much less the universe at large.

Sol and her children within the heliosphere are unimaginably tiny…

IVAN3MAN_AT_LARGE
Member
IVAN3MAN_AT_LARGE
June 2, 2010 8:08 AM

Drunk Vegan:

Sol and her children within the heliosphere are unimaginably tiny…

Which is why some of those children cannot let go of the ‘god’ security blanket…

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
June 2, 2010 8:31 AM

The _real_ Voyager anomaly. The good news is that the bit flip rate seems low.

Sol and her children within the heliosphere are unimaginably tiny…

Yes, but Voyager 2 is 92 au away. The Oort Cloud is, apparently, ~ 50 000 – 100 000 au or ~ 1-2 ly in radius. So we will have to wait some more before Voyager has metered out the system.

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
June 2, 2010 9:10 AM

Drats. Those aliens infiltrators were looking good for a while!

tripleclean
Member
tripleclean
June 2, 2010 9:34 AM

Hi,

I could any one explain what type science data is being transmitted back to earth. Do the cameras still work? thanks.

cshArpe
Member
cshArpe
June 2, 2010 1:11 PM
jjv
Member
jjv
June 3, 2010 1:32 AM
Sol and her children within the heliosphere are unimaginably tiny… Which is why some of those children cannot let go of the ‘god’ security blanket… ************************************************** The Left (of which you are a member, for sure) always seems so smug and proud of their “non belief” in God. Belief is free and brings comfort and inspiration to many. It is believed that at death believers who have lived a good and decent life will spend eternity with their God. This will bring to them eternal happiness, not a bad thing. OTH, according to Scripture, a non believer, whether he/she lives a good life or not will never enter the Kingdom of Heaven and will suffer eternally for their… Read more »
Steve Nerlich
Member
June 3, 2010 2:37 AM

Ooh a reality moment.

I had lunch in the cafeteria with some of the operations folks at Canberra DSN on Saturday.

Me: So, hey – I hear there’s a glitch with Voyager 2?

Guy who works for freaking NASA: Oh yeah, it’s just a flipped bit, everythings OK now.

Me: The old flipped bit again, huh? (nods wisely and googles flipped bit when at safe distance from cafeteria).

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
June 3, 2010 8:06 AM

@ jjv:

First, nitpicks:
– Atheism is rejection of religion, not hankering to ideologies. If anything, people who are skeptics can be suspicious to ideologies.

– There is no “Left” ideology. You may mean liberals vs conservatives, which is the main spectra AFAIK.

Second, your OT topic. Thank you for confirming IVAN3MAN_AT_LARGE’s model, not that we needed that. Indeed it is a needless security blanket.

The post-semitic death cult is especially pernicious to a sane judgment of facts. It is the knowledge that life is short that gives depth to the wonders of the universe that we see.

And please, making the daft Pascal’s wager is not an argument.

IVAN3MAN_AT_LARGE
Member
IVAN3MAN_AT_LARGE
June 3, 2010 9:12 AM

@ jjv:

The Left (of which you are a member, for sure) always seems so smug and proud of their “non belief” in God.

For your information, I am apolitical as well as an atheist — hence the suffix “3MAN” (Freeman) to my name.

So, what harm comes with a belief in something better after death if that belief causes one to live a better life?

That belief is your prerogative; however, it’s when religious fundamentalist busybodies endeavour to impose their ‘beliefs’ on me and my fellow comrades, by insisting that the Earth is only 6,000-years-old(!), that dinosaurs ‘walked’ with people, and that ‘light was much faster’ in the past, then I have a problem with those people.

Aodhhan
Member
Aodhhan
June 3, 2010 9:30 AM

What harm is there in a “white lie”?

One man’s security blanket is another man’s ball and chain.

“a better life” is a very subjective term.

IVAN3MAN_AT_LARGE
Member
IVAN3MAN_AT_LARGE
June 3, 2010 9:33 AM

@ jjv,

P.S. Evolution happened — DEAL WITH IT!

jim.powers
Member
jim.powers
June 3, 2010 9:58 AM
There is also a distinct difference between atheists and people who are antireligious. Simply: Atheists do not believe in god. People who are Antireligious are bigots. Your belief or disbelief in god does not matter in any way to me. How you treat others.. well, that’s a different story. Using any criteria to judge someone beneath you is as primitive as it gets. Tolerance for all the ways that people are different is the path to true enlightenment. Now, can we talk about Voyager? It’s kind of crazy to me that they were able to figure out what was wrong from so far away. Pretty awesome if you ask me, especially considering that lots of the guys who… Read more »
IVAN3MAN_AT_LARGE
Member
IVAN3MAN_AT_LARGE
June 3, 2010 11:31 AM
@ jim.powers: It’s kind of crazy to me that they were able to figure out what was wrong from so far away. […], especially considering that lots of the guys who worked on the program before it left [E]arth have retired, moved on or passed on. It shows a great deal of effort and time have been put into documenting things, and passing on knowledge so that these kinds of issues can be resolved. That’s why all computer programmers (including me) are taught to draw up a detailed flowchart showing each stage of the software in question — not only for the benefit of other software engineers, who may need to address any issues at a later stage,… Read more »
ND
Member
ND
June 4, 2010 4:42 AM

Anyone know the hardware used for the computers on the V’gers?

IVAN3MAN_AT_LARGE
Member
IVAN3MAN_AT_LARGE
June 4, 2010 7:13 AM
@ ND, It has been claimed that the “V’gers” were controlled by a version of the RCA (CDP)1802 “COSMAC” microprocessor, but it was not available at the time those spacecraft were being designed, and primary sources describe the Voyager computers as having architectures very dissimilar to the 1802, and not being microprocessor-based. There are three different computer types on the Voyager spacecraft and there are two of each kind. Total number of words among the six computers is about 32K. Computer Command System (CCS) – 18-bit word, interrupt type processors (2) with 4096 words each of plated wire, non-volatile memory. Flight Data System (FDS) – 16-bit word machine (2) with modular memories and 8198 words each. Attitude and… Read more »
ND
Member
ND
June 4, 2010 9:18 PM

Thanks IVAN3MAN. Good info. Amazing what’s possible to accomplish with such hardware.

“the computers were manufactured by General Electric to JPL specifications.”

So these appear to custom hardware and not commercial ones.

I’ve always wondered what sort of computer system were on those probes.

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