Just because LightSail-A shut down, does that mean it failed?
Right, but this requires the computer to be able to interpret the uplinked commands - which if it is frozen, it will not. Not including a hardware watchdog timer is a poor design decision.
Quote from: Andrewwski on 05/27/2015 05:19 pmRight, but this requires the computer to be able to interpret the uplinked commands - which if it is frozen, it will not. Not including a hardware watchdog timer is a poor design decision.Based on what you said up-thread it sounds like this system does not have a watchdog, or a watchdog enabled by default. That said, it is also possible to screwup the implementation of a watchdog. If done wrong, it could be updating the watchdog while still stuck...
Raise your hand for how many times you tested something, had it pass SQA, get released to the wild, and then found the SQA test didn't cover everything and had to issue a fast patch. I would raise my hand, but I don't have enough
Solar sails seem to be functioning under something of a curse, don't they? I'm aware of three vehicles so far. One was Japanese and didn't work, one was American and never flew because the contractor's internal organisational issues led to its cancellation, now LightSail-1's apparent brain-death.How long will they keep monitoring the vehicle for a reboot? It would be a shame if they give up after a month and then, a month later, the vehicle restarts, deploys and soars off with no-one the wiser!
Quote from: Ben the Space Brit on 05/28/2015 01:02 pmSolar sails seem to be functioning under something of a curse, don't they? I'm aware of three vehicles so far. One was Japanese and didn't work, one was American and never flew because the contractor's internal organisational issues led to its cancellation, now LightSail-1's apparent brain-death.How long will they keep monitoring the vehicle for a reboot? It would be a shame if they give up after a month and then, a month later, the vehicle restarts, deploys and soars off with no-one the wiser!You missed NASA's NanoSail-D and NanoSail-D2. The first was lost in a falcon 1 launch failure, the other was launched on a Minotaur-4 in 2010. http://space.skyrocket.de/doc_sdat/nanosail-d.htm
One was Japanese and didn't work, [...]
IKAROS (launched with Akatsuki) did work, and so successfully they're still in contact with it after solar opposition!http://global.jaxa.jp/projects/sat/ikaros/
Well the luck is there! LightSail's computer has re-booted 8 hours ago! http://www.planetary.org/blogs/jason-davis/2015/20150530-lightsail-phones-home.html
Let's hope the computer stays on.
102 LightSail packets received since yesterday. Team attempting software patch; rebooted manually to keep troublesome beacon.csv in check.