Voyager Calling Home.....

EppyGA

EppyGA

Touchdown! Greaser!
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Let's Fly
The aliens that abducted the spacecraft were apparently quite small, having abducted only 1 bit in the computer's memory. NASA abducted it back. It's your move, ALF.

http://www.nasa.gov/mission_pages/voyager/voyager20100506.html
Updated May 24, 2010 at 5:30 p.m. PDT
Engineers successfully reset a computer onboard Voyager 2 that caused an unexpected data pattern shift, and the spacecraft resumed sending properly formatted science data back to Earth on Sunday, May 23. Mission managers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., had been operating the spacecraft in engineering mode since May 6. They took this action as they traced the source of the pattern shift to the flip of a single bit in the flight data system computer that packages data to transmit back to Earth. In the next week, engineers will be checking the science data with Voyager team scientists to make sure instruments onboard the spacecraft are processing data correctly.​
-harry
 
sba55 said:
It's simply astonishing that this 30 year old spacecraft is still working.
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I agree 1000%... The fact it is still operational is a wonderful tribute to NASA in their early years.. They could not do that today even if they spent 5 billion dollars. :nono::nono:
 
N801BH said:
I agree 1000%... The fact it is still operational is a wonderful tribute to NASA in their early years.. They could not do that today even if they spent 5 billion dollars. :nono::nono:
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You need to look at what they are doing with the Mars landers. Those too are running well past their 18 month lifetimes. NASA started those in early 2000 with a launch in 2003 for just under $820 million.
 
ScottM said:
You need to look at what they are doing with the Mars landers. Those too are running well past their 18 month lifetimes. NASA started those in early 2000 with a launch in 2003 for just under $820 million.
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They are clever little vehicles for sure... I kinda got tainted on that program when they crashed the first probe into the surface because after spending 100's of millions of dollars the whole batch of "rocket scientists" forget to convert metric to US measurements.


How dumb was that ??????????????? :mad2::mad2::mad2::yikes:
 
N801BH said:
They are clever little vehicles for sure... I kinda got tainted on that program when they crashed the first probe into the surface because after spending 100's of millions of dollars the whole batch of "rocket scientists" forget to convert metric to US measurements.


How dumb was that ??????????????? :mad2::mad2::mad2::yikes:
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About as dumb as almost destroying a moon mission and killing 3 astronauts by changing the voltage specs. Then having the tank vendor, Beechcraft BTW, not upgrade their 28VDC thermostats to handle the 65VDC ground voltage.

Or we can also talk about using 100% O2 at 15psi for a plugs out test on manned missions and what that cost us.

Space travel is tough and it costs money. These space craft are very complex and the details can really bite you!
 
ScottM said:
You need to look at what they are doing with the Mars landers. Those too are running well past their 18 month lifetimes. NASA started those in early 2000 with a launch in 2003 for just under $820 million.
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One of them just died because the solar array got knocked off by the winds during the winter. The orbiting probe took a picture that showed one panel gone.
 
mikea said:
One of them just died because the solar array got knocked off by the winds during the winter. The orbiting probe took a picture that showed one panel gone.
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Interesting. I know that there have been some problems, as one would expect when you go past your estimate life time. But I had not heard about this latest news. on the Mars website http://marsrover.nasa.gov/home/
 
mikea said:
One of them just died because the solar array got knocked off by the winds during the winter. The orbiting probe took a picture that showed one panel gone.
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ScottM said:
Interesting. I know that there have been some problems, as one would expect when you go past your estimate life time. But I had not heard about this latest news. on the Mars website http://marsrover.nasa.gov/home/
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Not one of the rovers. This was the lander that landed near the Martian north pole. The rovers are alive. Well, Spirit is hibernating, but there is hope that it will revive as the Martian spring approaches.
 
ScottM said:
You need to look at what they are doing with the Mars landers. Those too are running well past their 18 month lifetimes. NASA started those in early 2000 with a launch in 2003 for just under $820 million.
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The rovers warranty was for 90 days after landing. That expired multiple years ago. One is still trundling along, the other got high centered and is hibernating to protect it's systems.
 
sba55 said:
It's simply astonishing that this 30 year old spacecraft is still working.
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I wonder what kind of computer they had 30 years ago. Perhaps a Tandy from Radio Shack? Did they have 186s yet? I'm surprised they even have people who understand that old programing still. Do you think it uses DOS?

That it continues to process data at all is amazing in itself.

Then again, it's way hell and gone out there in the vacuum of space, probably isn't all that much data to process anyway.

:smile:

John
 
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John Baker said:
I wonder what kind of computer they had 30 years ago. Perhaps a Tandy from Radio Shack? Did they have 186s yet? I'm surprised they even have people who understand that old programing still. Do you think it uses DOS?

That it continues to process data at all is amazing in itself.

Then again, it's way hell and gone out there in the vacuum of space, probably isn't all that much data to process anyway.

:smile:

John
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I don't know the processor specs, but there is plenty of data yet to be gathered- neither probe has breached the sun's shockwave yet; that's the real dividing line between "the solar system" and "deep space".
It would be really cool to get any kind of signal from that region of space... I don't think the original designers, programmers, and mission planners thought it would go on so long!
 
rottydaddy said:
I don't know the processor specs, but there is plenty of data yet to be gathered- neither probe has breached the sun's shockwave yet; that's the real dividing line between "the solar system" and "deep space".
It would be really cool to get any kind of signal from that region of space... I don't think the original designers, programmers, and mission planners thought it would go on so long!
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What does it use for a power supply?
 
Hey, easy on that obsolete old guy stuff... Some of us are still around who can write machine language code for a 6502... But things have moved on, lordy how I would have killed for a high level language and a compiler in those days... I used to wake up at 3AM with a start thinking I forgot to do a bit shift in a bubble sort subroutine and be halfway downstairs before I realized I had been dreaming it...

denny-o
 
John Baker said:
I wonder what kind of computer they had 30 years ago. Perhaps a Tandy from Radio Shack? Did they have 186s yet? I'm surprised they even have people who understand that old programing still. Do you think it uses DOS?

That it continues to process data at all is amazing in itself.

Then again, it's way hell and gone out there in the vacuum of space, probably isn't all that much data to process anyway.

:smile:

John
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I was working on 186s in 1984. Not a bad machine. It was pre-Windows, but powerful enough for us to be writing a character-based UI with menus and buttons. As far as I know, only Tandy made a 186 machine.
 
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AuntPeggy said:
I was working on 186s in 1984. Not a bad machine. It was pre-Windows, but powerful enough for us to be writing a character-based UI with menus and buttons. As far as I know, only Tandy made a 186 machine.
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Memory may be slipping here but first one I played with was the 4004 in 76. Then in 78 or 79 moved into the 8008 and Z80 class of machine. Talk about powerful.:D

At the same time, although I didn't get involved until later, a group I worked with and later for built a custom system using Motorola 2901 4 bit slices combined into a 16 bit processor. The system then used four of those processors in specifc roles to provides some real power, tied to a washtub 300 MB disk and we were unstoppable.:aureola:
 
Dr. O said:
Hey, easy on that obsolete old guy stuff... Some of us are still around who can write machine language code for a 6502... But things have moved on, lordy how I would have killed for a high level language and a compiler in those days...
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I can do the 6502 machine code too.

Could you imagine the high failure rate and terrabytes of memory that would be required for a modern visual programmer to write the equivalent code that's on voyager? I seriously doubt the so called high tech advanced reliable designed laptop I'm typing this on will be operational in 10 years due to catastrophic hardware failure. In 30 more years, my Apple IIe and Voyager will likely be the only old machines still running.
 
http://voyager.jpl.nasa.gov/faq.html
What kind of computers are used on the Voyager spacecraft?

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 Articulation Control System (AACS) - 18-bit word machines (2) with 4096 words each.

According to my calulations, that's a total of about 541KB, or small potatoes compared to today's microprocessors. We probably could perform all functions with one of today's boards and still have room for solid state data storage and much more fault detection software. We would still need a second unit for redundancy. Today's microprocessors are also much faster than the chips used on Voyager and a comparative system would use less electrical power. On the other hand, software might be more complicated as opposed to that used in an interrupt type system, but it would be much more capable and more flexible.

Let's look closer at the CCS. The CCS has two main functions: to carry out instructions from the ground to operate the spacecraft, and to be alert for a problem or malfunction and respond to it. Two identical 4096- word memories contain both fixed routines (about 2800 words) and a variable section (about 1290 words) for changing science sequences. The CCS issues commands to the AACS for movement of the scan platform or spacecraft maneuvers; to the FDS for changes in instrument configurations or telemetry rates and to numerous other subsystems within the spacecraft for specific actions. Fault-protection algorithms are also stored in the CCS, occupying roughly 10 percent of the CCS memory.

The main functions of the FDS are to collect data from, and controls the operations of, the scientific instruments; and to format engineering and science data for on-board storage and/or real-time transmission. The FDS also keeps the spacecraft "time" and provides frequency references to the instruments and other spacecraft subsystems.

The Voyager spacecraft computers are interrupt driven computer, similar to processors used in general purpose computers with a few special instructions for increased efficiency. The programming is a form of assembly language.

There is no clock chip, as such, in the spacecraft. The "clock" is really a counter, based on one of several electronically generated frequencies. These frequencies, based on a reference, generated by a very stable oscillator, are converted and fed to different locations in the spacecraft as synchronization signals, timers, counters, etc. The "clock" signal is part of the information telemetered to the ground and it is with ground software that we convert to day of year, time of day Greenwich Mean Time.

Voyager was built in-house at JPL; the computers were manufactured by General Electric to JPL specifications.​
-harry
 
And..... The amazing thing is Voyager is operating in an enviourment about -410 F.

Kinda hard to believe all the solder joints and hardware of the entire spacecraft are holding up so good. :smile:
 
Dr. O said:
Hey, easy on that obsolete old guy stuff... Some of us are still around who can write machine language code for a 6502... But things have moved on, lordy how I would have killed for a high level language and a compiler in those days... I used to wake up at 3AM with a start thinking I forgot to do a bit shift in a bubble sort subroutine and be halfway downstairs before I realized I had been dreaming it...

denny-o
Click to expand...

I learned on the 65C02...BRA was a very handy instruction.
 
Henning said:
What does it use for a power supply?
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>>
[FONT=Verdana, Arial, Helvetica, sans-serif]Spacecraft electrical power is supplied by Radioisotope Thermoelectric Generators (RTGs) that provided approximately 470 w of 30 volt DC power at launch. Due to the natural radioactive decay of the Plutonium fuel source, the electrical energy provided by the RTGs is continually declining. At the beginning of 2008, the power generated by Voyager 1 had dropped to ~ 285 w and to~ 287 w for Voyager 2. Both of these power levels represent better performance than the pre-launch predictions, which included a conservative degradation model for the bi-metallic thermocouples used to convert thermal energy into electrical energy. As the electrical power becomes less and less, power loads on the spacecraft must be turned off in order to avoid having demand exceed supply. As loads are turned off spacecraft capabilities are eliminated. The following table identifies the year when specific capabilities have or will end as a result of the available electrical power limitations. [/FONT]
<<

from:
http://voyager.jpl.nasa.gov/spacecraft/spacecraftlife.html

Sounds like a radioactive heat source. Thermocouples then convert the heat to electricity.
 
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