I’m a little sad and disappointed about this, bacause as a Kickstarter supporter I felt a wholly-unwarranted slight sense of ownership.
As of late Friday afternoon, LightSail was continuing to operate normally. The spacecraft’s ground stations at Cal Poly San Luis Obispo and Georgia Tech were receiving data on each pass. Power and temperature readings were trending stably, and the spacecraft was in good health.
But every time LightSail transmitted a packet, it stored a copy in a datafile file called beacon.csv. This continued until the file reached 32 megabytes and crashed the system.
There was a patch already in place, but the version they sent didn’t include it. They were going to beam the patch up, but by the time they got around to it it was already dead…
Apparently it would work if it were reset. There is a physical reset button…
“There’s nobody in outer space to push that reset button,” says [Bill] Nye.
Since we can’t send anyone into space to reboot LightSail, we may have to wait for the spacecraft to reboot on its own. Spacecraft are susceptible to charged particles zipping through deep space, many of which get trapped inside Earth’s magnetic field. If one of these particles strikes an electronics component in just the right way, it can cause a reboot.
So their only hope is a convenient passing cosmic ray.
I worry this is to be expected with citizen science. It’s awesome that the Planetary Society did this, but I think if this were a NASA project the chances of a stupid error like this would have been miniscule. NASA has had a few famous examples of software bugs, but their recent stuff is just about the most well-tested, perfectly running software in the world.
But how much work the software does is not what makes it remarkable. What makes it remarkable is how well the software works. This software never crashes. It never needs to be re-booted. This software is bug-free. It is perfect, as perfect as human beings have achieved. Consider these stats : the last three versions of the program — each 420,000 lines long-had just one error each. The last 11 versions of this software had a total of 17 errors. Commercial programs of equivalent complexity would have 5,000 errors.
And guys, a physical button? Not a second system that you can beam to as an external rebooting service?
(Paging @frauenfelder as it’s an interesting topic.)