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NASA To Repair Hubble By Remote Control
Matt_dk writes "NASA says it plans to fix the Hubble Space Telescope by remote control this week.
The Hubble stopped beaming information to Earth about two weeks ago, when a data unit on the telescope completely failed.
Scientists on Tuesday said they will bypass the failed unit and switch to a back-up system to restart the flow of information.
The computer glitch forced NASA to postpone a shuttle mission this month to repair the Hubble.
That shuttle mission has been postponed until next year."
Update - 10/15, 17:45 by SS: Readers have pointed out further details from Spaceflight Now and the NASA press release.
I don't get the whole thing. I mean, why does it take two weeks to say "Main system offline, switching to backup."?
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
I'm curious, I presume somebody knows this.
.. or just look at this http://en.wikipedia.org/wiki/List_of_notable_software_bugs
A satellite is the ultimate inaccessible device running SW. Any task that goes wrong has the chance of bricking a device that cost many many millions, so they *must* practice and check all commands sent to it when things go wrong.
Do they have several mock ups?
A complete computer model of the whole thing, emulated right down to hardware and software?
How are reboot/reprogram sequences like this handled/practiced/tested?
Even at design stage I imagine failure modes are extensively analyzed and multiple redundancy built in.
My company builds stuff that goes up masts and is generally quite inaccessible and we always attempt to prove these things first, but we had fast serial communication, low level boot loaders under all the SW and if the worst comes somebody can climb the mast.
Anybody know how space tech is handled?
On a kind of related note, google for "expensive software errors" - most of the top ten are space related...