Mission status, LightSail

The Planetary Society’s LightSail test mission is paused while engineers wait out a suspected software glitch that has silenced the solar sailing spacecraft. Following a successful start to the mission last Wednesday, LightSail spent more than two days sending about 140 data packets back to Earth.
But the long Memorial Day weekend here in the United States offered no respite for the LightSail team, as they scrambled to figure out why the spacecraft's automated telemetry chirps suddenly fell silent. It is now believed that a vulnerability in the software controlling the main avionics board halted spacecraft operations, leaving a reboot as the only remedy to continue the mission. When that occurs, the team will likely initiate a manual sail deployment as soon as possible.

What happened?

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 inside the spacecraft's Linux-based flight software, a problem was brewing. Every 15 seconds, LightSail transmits a telemetry beacon packet. The software controlling the main system board writes corresponding information to a file called beacon.csv. If you’re not familiar with CSV files, you can think of them as simplified spreadsheets—in fact, most can be opened with Microsoft Excel.
As more beacons are transmitted, the file grows in size. When it reaches 32 megabytes—roughly the size of ten compressed music files—it can crash the flight system. The manufacturer of the avionics board corrected this glitch in later software revisions. But alas, LightSail’s software version doesn’t include the update.
Late Friday, the team received a heads-up warning them of the vulnerability. A fix was quickly devised to prevent the spacecraft from crashing, and it was scheduled to be uploaded during the next ground station pass. But before that happened, LightSail fell silent. The last data packet received from the spacecraft was May 22 at 21:31 UTC (5:31 p.m. EDT).
LightSail is likley now frozen, not unlike the way a desktop computer suddenly stops responding. A reboot should clear the contents of the problematic beacon.csv file, giving the team a couple days to implement a fix. But to pull a phrase from recent mission reports, the outcome of the freeze is “non-deterministic.” That means sometimes the processor will still accept a reboot command; other times, it won’t. It’s similar to the way you deal with a frozen computer: You can try to struggle past sluggish menus and click reboot, but sometimes, your only recourse is pressing the power button.
As of Tuesday afternoon, there have been 37 Cal Poly and Georgia Tech ground station passes. During half of those, reboot commands were sent to the spacecraft. Nothing has happened yet. Therefore, we have to assume that LightSail is only going to respond to the power button method.
Since we can’t send anyone into space to reboot LightSail, we may have to wait for the spacecraft to reboot on its own.
Source: http://www.planetary.org/blogs/jason-davis/2015/20150526-software-glitch-pauses-ls-test.html