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The part that caught my eye was redundancy on memory. >> Hubble’s operators initially thought a memory module was at fault but switching to one of three backup

The part that caught my eye was redundancy on memory. >> Hubble’s operators initially thought a memory module was at fault but switching to one of three backup modules produced the same error. Apparently Hubble has 4 memory modules which are switchable! I'd love to see how that works. Actually, I'd be fascinated to get a walkthrough of the overall architecture. It might give insights for how we keep business continuity by first accepting that hardware and software will fail.

belter 5y ago
Posted this before here. Maybe worthwhile to post again... Fig 5-10 is the Data Management Subsystem https://asd.gsfc.nasa.gov/archive/sm3a/downloads/sm3a_media_guide/HST-systems.pdf https://asd.gsfc.nasa.gov/archive/sm3a/downloads/sm3a_media_... Concerning the computers: - First they had a DF-224 flight computer and a - Science Instrument Control and Data Handling (SI C&DH) Initially DF-224 between missions got installed a coprocessor: https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/CoProcessor.pdf https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/Co... During another servicing mission they replaced it with something called the Advanced Computer with Intel 80486: https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/FS09.pdf https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/FS... There are some 50,000 lines of code in the C and Assembly programming languages. https://www.nasa.gov/pdf/327688main_09_SM4_Media_Guide_rev1.pdf https://www.nasa.gov/pdf/327688main_09_SM4_Media_Guide_rev1.... They also have a Help Desk... "Welcome to the Hubble Space Telescope Help Desk" https://stsci.service-now.com/hst?id=hst_index https://stsci.service-now.com/hst?id=hst_index
Nition 5y ago
Classic movie scenario. Hubble's down, and we need it now. No-one can solve the errors. Old guy walks in, worked on Hubble 30 years ago. "There's a backup module, with an override command to activate it, but it won't work with the system down. You'll have to use the manual override switch - on the telescope."
garaetjjte 5y ago
It was 64k of core memory originally, but it was later replaced by redundant 4x 64k CMOS memory. https://youtu.be/RWUnC2uf3XY?t=406 https://youtu.be/RWUnC2uf3XY?t=406

belter 5y ago

Posted this before here. Maybe worthwhile to post again... Fig 5-10 is the Data Management Subsystem https://asd.gsfc.nasa.gov/archive/sm3a/downloads/sm3a_media_guide/HST-systems.pdf https://asd.gsfc.nasa.gov/archive/sm3a/downloads/sm3a_media_... Concerning the computers: - First they had a DF-224 flight computer and a - Science Instrument Control and Data Handling (SI C&DH) Initially DF-224 between missions got installed a coprocessor: https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/CoProcessor.pdf https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/Co... During another servicing mission they replaced it with something called the Advanced Computer with Intel 80486: https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/FS09.pdf https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/FS... There are some 50,000 lines of code in the C and Assembly programming languages. https://www.nasa.gov/pdf/327688main_09_SM4_Media_Guide_rev1.pdf https://www.nasa.gov/pdf/327688main_09_SM4_Media_Guide_rev1.... They also have a Help Desk... "Welcome to the Hubble Space Telescope Help Desk" https://stsci.service-now.com/hst?id=hst_index https://stsci.service-now.com/hst?id=hst_index

Nition 5y ago

Classic movie scenario. Hubble's down, and we need it now. No-one can solve the errors. Old guy walks in, worked on Hubble 30 years ago. "There's a backup module, with an override command to activate it, but it won't work with the system down. You'll have to use the manual override switch - on the telescope."

garaetjjte 5y ago

It was 64k of core memory originally, but it was later replaced by redundant 4x 64k CMOS memory. https://youtu.be/RWUnC2uf3XY?t=406 https://youtu.be/RWUnC2uf3XY?t=406