4 ms·
Lightsail satellite hangs due to 32Mb CSV file
- ColinWright 11y agoI'm somewhat bemused by this. It's standard in embedded systems of any type always to audit every write to file to make sure the file isn't growing too large. I wonder what sort of vetting this software went through before being deployed. Does anyone know more about this project, and the process it went through before launch?
- kwhitefoot 11y agoMe too. Also, isn't there a watchdog circuit that would reboot if a heartbeat fails? I haven't worked in embedded controllers for many years but such things used to be common in embedded systems. At least Atmel processors have them built in: http://www.embedds.com/using-watchdog-timer-in-your-projects/ http://www.embedds.com/using-watchdog-timer-in-your-projects... I realize that the Lightsail is a bit more complicated but the principle remains valid.
- techdragon 11y agoYou build a spacecraft without a watchdog. You'll soon be regretting building a spacecraft without a watchdog. Systems engineering 101 stuff, the watchdog is a fail safe on the software system. For those unfamiliar with a watchdog, think of it as STONITH for a single mode system, you design it with two copies of the operating system on two drives or partitions and then if the watchdog doesn't get a response from the computer it forces hard reboot and the system reboots using drive 2, and you send instructions to it to to check drive 1 or wipe it or whatever you want.
- breakingcups 11y agoI would've assumed a completely seperate system listening on a different frequency just to reboot the system would be in place in a system as complex as this one.