The Voyagers

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Profile Lynn Special Project $75 donor
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Message 1187560 - Posted: 23 Jan 2012, 0:38:17 UTC - in response to Message 1187211.  

Thanks for the update Lynn L. One wounders now if NASA had wished that they
had built in a greater power source at the time this craft was built.



you're welcome, Nick. NASA, most likely would now think differently.
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Message 1187594 - Posted: 23 Jan 2012, 4:38:45 UTC - in response to Message 1187560.  
Last modified: 23 Jan 2012, 4:57:41 UTC

Thanks for the update Lynn L. One wounders now if NASA had wished that they
had built in a greater power source at the time this craft was built.



you're welcome, Nick. NASA, most likely would now think differently.



From the memory of an Old Fart,

IIRC, there was quite a bit of controversy over the planned RTG power plants. Putting a nuclear reactor, using U-238, on a rocket wasn't looked upon by the public as the best idea in the world at the time.

U-238 has a long half-life of almost ~4.5 billion years, so, the fear was that if anything went wrong during launch or until the craft reached escape velocity, there was a chance of a major environmental impact.

I believe NASA did well to get what they got.

Lt

edited...
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Message 1187605 - Posted: 23 Jan 2012, 5:45:10 UTC

AFAIK U-238 is not fissile, only fertile. Natural Uranium has a small percentage of U-235 (0.7 %) which enables it to be used in a reactor having heavy water as moderator, like in Canada's CANDU (Canada Deuterium Uranium).
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Message 1187615 - Posted: 23 Jan 2012, 7:30:03 UTC

The material in the modified SNAP-19's on Voyager is Pu238. Half life about 87 years. However the thermocouples are decaying faster.


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Message 1187671 - Posted: 23 Jan 2012, 14:39:14 UTC - in response to Message 1187615.  

The material in the modified SNAP-19's on Voyager is Pu238. Half life about 87 years. However the thermocouples are decaying faster.




Thanks for the corrections!

Lt

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Message 1885719 - Posted: 24 Aug 2017, 4:03:29 UTC

Just watched a new interesting documentary about these fascinating Voyagers.

40 years ago they were launched.
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Message 1885721 - Posted: 24 Aug 2017, 4:21:49 UTC - in response to Message 1885719.  
Last modified: 24 Aug 2017, 4:23:55 UTC

Just watched a new interesting documentary about these fascinating Voyagers.

40 years ago they were launched.

http://www.npr.org/sections/13.7/2017/08/23/545484098/to-infinity-and-beyond-celebrating-40-years-of-the-voyager-mission

This is the show I just watched:

http://www.pbs.org/the-farthest/home/
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Message 1885729 - Posted: 24 Aug 2017, 5:14:00 UTC - in response to Message 1885721.  

If Voyager were to travel to Proxima Centauri, at this rate, it would take over 73,000 years to arrive.

That's a long time!
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Message 1888084 - Posted: 6 Sep 2017, 8:44:38 UTC

NASA revealed the winning #MessageToVoyager and beamed it into space.
https://youtu.be/5VzVyYbPbJY
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Message 1888237 - Posted: 7 Sep 2017, 0:42:56 UTC

Thanks to Carl Sagan for persuading the Voyager team to turn the camera back toward Earth for the famous pale blue dot picture. :~)
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Message 1888239 - Posted: 7 Sep 2017, 0:50:30 UTC - in response to Message 1888084.  

NASA revealed the winning #MessageToVoyager and beamed it into space.
https://youtu.be/5VzVyYbPbJY

I love that William Shatner was alive to take part in this!
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Message 1890677 - Posted: 18 Sep 2017, 23:54:19 UTC

Nice article about the Golden Records aboard the Voyagers:

https://www.newyorker.com/tech/elements/voyager-golden-record-40th-anniversary-timothy-ferris
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Message 1904479 - Posted: 2 Dec 2017, 20:23:53 UTC

Thrusters fired!
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Message 1904757 - Posted: 4 Dec 2017, 8:56:25 UTC

I loved the Viking mission to Mars, and it communicated back to earth for a long time, all things considering it was a planetary lander, but the Voyager mission is so beyond anything the earth ever has sent out into space, I really love hearing about it still being alive out there. The fact that it can still receive and process physically functional commands is truly amazing to me. I wish I was on the staff of it's control center so I could celebrate with them. :~)
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Message 1904789 - Posted: 4 Dec 2017, 15:51:49 UTC
Last modified: 4 Dec 2017, 15:52:46 UTC

The computers of the Voyagers have programs written in an outdated assembler language, according to NASA, and maybe NASA had problems finding programmers who knew that assembler. Having worked with theZilog Z80 assembler, maybe I can start a new career. We used eight inch floppies,, 20 MByte Winchester disks and 10 Mbyte tapes, on which we made daily incremental backups.
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Message 1904842 - Posted: 4 Dec 2017, 20:17:40 UTC - in response to Message 1904789.  

The computers of the Voyagers have programs written in an outdated assembler language, according to NASA, and maybe NASA had problems finding programmers who knew that assembler. Having worked with theZilog Z80 assembler, maybe I can start a new career. We used eight inch floppies,, 20 MByte Winchester disks and 10 Mbyte tapes, on which we made daily incremental backups.
Tullio

Perhaps the computers of the Voyagers are not even coded with assembler language.
The Apollo moonlanders where not.
Just hard coded machine language.
https://history.nasa.gov/computers/Ch6-2.html
The computers aboard the Voyager probes each have 69.63 kilobytes of memory, total. That’s about enough to store one average internet jpeg file. The probes’ scientific data is encoded on old-fashioned digital 8-track tape machines rather than whatever solid state drive your high-end laptop is currently using. Once it's been transmitted to Earth, the spacecraft have to write over old data in order to have enough room for new observations.
The Voyager machines are capable of executing about 81,000 instructions per second. The smart phone that is likely sitting in your pocket is probably about 7,500 times faster than that. They transmit their data back to Earth at 160 bits per second. A slow dial-up connection can deliver at least 20,000 bits per second.
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Message boards : Science (non-SETI) : The Voyagers


 
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