4 ms·

NASA usually has a duplicate system (full mechanicals, not just a simulation) to test things on to make sure they don't create a brick. NASA can also use the d

NASA usually has a duplicate system (full mechanicals, not just a simulation) to test things on to make sure they don't create a brick. NASA can also use the dupes as a backup in case there is an accident during launch and the first system gets destroyed.

forapurpose 9y ago
I wonder how well the 37 year old duplicate mechanicals work.
- amptorn 9y ago
  Well... as long as they work precisely as well (or badly) as the 37-year-old originals do, that's perfect, right?
- asciimo 9y ago
  They should be kept in a space-cold vacuum.
- olympus 9y ago
  The point really isn't to make sure the valves work (the environment might have broken them after a few decades in space), the point is to make sure the code you're uploading doesn't brick the computer. It's nice to have an original computer and fully replicated signal path to make sure there aren't any unforseen bugs. Emulators have a tendency to have 99% coverage but the missing 1% is what would cause us to throw an expensive brick out of the solar system.
oso2k 9y ago
This assertion is correct for the more recent robotic missions (Mars Science Lander, Mars Exploration Rovers (MER), Mars Pathfinder/Sojouner) but I don’t recall seeing or hearing about spares for earlier missions or satellite/spacecraft-based missions. Earlier missions would probably have had only an empty mechanical flight spare. I worked in the Spacecraft Assembly Facility at JPL and was very familiar with the Technical Inventory Management team (the group that managed storage and logistics for reusable and non-reusable technology assets). Generally speaking, we built at least 3 versions (4 versions depending how you count). 1) Flight. The one put in the payload. 2) Flight spare. Often used in one of the 2 or 3 Mars test facilities at (the 2 Mars yards or simulation facility) and hooked up to a spare Ground Data System (controller system) via a 6 inch thick, 100 foot long “umbilical cord”. 3) A mechanical flight spare. A usually 80-90% mechanically accurate version that we called Bubba (at least for MER) that we’d pull out for Open House, or other special events and displays. 4) Lastly, I personally worked with subsystem flight spares (44u rack of the Satellite Communication Subsystem or the Flight Control System). Way too big to fit in a spacecraft in this configuration or a mock-up of the system. What might be a more interesting story is how we bought dozens and dozens of old SUN pizza boxes and Sparc Stations in the mid and late 2000s from eBay (literally) in order to be able maintain the Flight Ground Data System.

forapurpose 9y ago

I wonder how well the 37 year old duplicate mechanicals work.

amptorn 9y ago
Well... as long as they work precisely as well (or badly) as the 37-year-old originals do, that's perfect, right?
asciimo 9y ago
They should be kept in a space-cold vacuum.
olympus 9y ago
The point really isn't to make sure the valves work (the environment might have broken them after a few decades in space), the point is to make sure the code you're uploading doesn't brick the computer. It's nice to have an original computer and fully replicated signal path to make sure there aren't any unforseen bugs. Emulators have a tendency to have 99% coverage but the missing 1% is what would cause us to throw an expensive brick out of the solar system.

oso2k 9y ago

This assertion is correct for the more recent robotic missions (Mars Science Lander, Mars Exploration Rovers (MER), Mars Pathfinder/Sojouner) but I don’t recall seeing or hearing about spares for earlier missions or satellite/spacecraft-based missions. Earlier missions would probably have had only an empty mechanical flight spare. I worked in the Spacecraft Assembly Facility at JPL and was very familiar with the Technical Inventory Management team (the group that managed storage and logistics for reusable and non-reusable technology assets). Generally speaking, we built at least 3 versions (4 versions depending how you count). 1) Flight. The one put in the payload. 2) Flight spare. Often used in one of the 2 or 3 Mars test facilities at (the 2 Mars yards or simulation facility) and hooked up to a spare Ground Data System (controller system) via a 6 inch thick, 100 foot long “umbilical cord”. 3) A mechanical flight spare. A usually 80-90% mechanically accurate version that we called Bubba (at least for MER) that we’d pull out for Open House, or other special events and displays. 4) Lastly, I personally worked with subsystem flight spares (44u rack of the Satellite Communication Subsystem or the Flight Control System). Way too big to fit in a spacecraft in this configuration or a mock-up of the system. What might be a more interesting story is how we bought dozens and dozens of old SUN pizza boxes and Sparc Stations in the mid and late 2000s from eBay (literally) in order to be able maintain the Flight Ground Data System.