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As the should. Voyagers are still active and this maintenance is needed in case issues occur. In a way due to the +24 hours oneway communication to correct so

by jmclnx 5mo ago

As the should. Voyagers are still active and this maintenance is needed in case issues occur. In a way due to the +24 hours oneway communication to correct software issues should they occur, this will help speed corrections up. Now I wonder how the test it ? Is it on a software emulator on modern equipment or do they have a Voyager replica ?

norman784 5mo ago
That would be an interesting project, I assume a lot of not so young engineers will want to play with it, as a hobby. Also if that project exists, I'm sure that someone will try to port DOOM.
- philipwhiuk 5mo ago
  https://github.com/Zaneham/voyager-fds-emulator https://github.com/Zaneham/voyager-fds-emulator
philipwhiuk 5mo ago
I believe they have both. Simulators for the spacecraft and replicas for some bits of hardware.
rcxdude 5mo ago
What they have is surprisingly fragmentary. For the recent software issue, they had to be very conservative in what they changed because they aren't 100% sure about the details of the ISA on the actual spacecraft (due to amiguity between different revisions of the wiring of the CPU), and so they don't really have a simulator they can trust.
- joseda-hg 5mo ago
  Maybe I'm used to think of NASA as this infinite budget agency, but considering Voyager's significance... To me that souns like we should test all revisions of the CPU, not none of them
  - rcxdude 5mo ago
    NASA hasn't had infinite budget for a long time. They didn't even have it when they were building the voyager probes (they were the budget version of what they wanted to build).
ndiddy 5mo ago
> Now I wonder how the test it ? They have a simulator for one of the three computers on Voyager, the Computer Command Subsystem. They don't have a simulator for the other two computers, the Attitude and Articulation Control Subsystem and the Flight Data Subsystem. They used to have a Voyager replica, the Capability Demonstration Lab, but they got rid of it after they moved the Voyager team into a satellite office following the end of the main mission. There's more information here if you're interested: https://arc.aiaa.org/doi/pdf/10.2514/6.2016-2415 https://arc.aiaa.org/doi/pdf/10.2514/6.2016-2415

by jmclnx 5mo ago

norman784 5mo ago

That would be an interesting project, I assume a lot of not so young engineers will want to play with it, as a hobby. Also if that project exists, I'm sure that someone will try to port DOOM.

philipwhiuk 5mo ago
https://github.com/Zaneham/voyager-fds-emulator https://github.com/Zaneham/voyager-fds-emulator

philipwhiuk 5mo ago

I believe they have both. Simulators for the spacecraft and replicas for some bits of hardware.

rcxdude 5mo ago

What they have is surprisingly fragmentary. For the recent software issue, they had to be very conservative in what they changed because they aren't 100% sure about the details of the ISA on the actual spacecraft (due to amiguity between different revisions of the wiring of the CPU), and so they don't really have a simulator they can trust.

joseda-hg 5mo ago
Maybe I'm used to think of NASA as this infinite budget agency, but considering Voyager's significance... To me that souns like we should test all revisions of the CPU, not none of them
- rcxdude 5mo ago
  NASA hasn't had infinite budget for a long time. They didn't even have it when they were building the voyager probes (they were the budget version of what they wanted to build).

ndiddy 5mo ago

> Now I wonder how the test it ? They have a simulator for one of the three computers on Voyager, the Computer Command Subsystem. They don't have a simulator for the other two computers, the Attitude and Articulation Control Subsystem and the Flight Data Subsystem. They used to have a Voyager replica, the Capability Demonstration Lab, but they got rid of it after they moved the Voyager team into a satellite office following the end of the main mission. There's more information here if you're interested: https://arc.aiaa.org/doi/pdf/10.2514/6.2016-2415 https://arc.aiaa.org/doi/pdf/10.2514/6.2016-2415