The test flight of Carl Sagan's LightSail craft is in jeopardy after a computer problem left it unable to communicate with its mission controllers. According to the Planetary Society, the hardware was launched into space with an older version of its Linux-based operating system, which shipped with a serious glitch. As the vehicle circuits the planet, it's meant to send back a packet of data, but over the first two days, this file grew too big for the system to handle. As such, it crashed, although we mean that in the software sense, rather than the coming-back-to-Earth-with-a-bump sense.
Unfortunately, controllers have already attempted to restart the system 18 times, but the hardware is refusing to accept the command. There is a hope, however, that LightSail could reboot itself of its own accord, should it come into contact with charged particles that are trapped inside the atmosphere. Researchers at Cal Poly believe that it's a standard occurrence for cube satellites like the LightSail, and it should take place within the first three weeks of launch. If there's a downside, it's that the deployment timeline only runs for 28 days, so there's a lot resting on this happy accident. It is possible to reboot the device manually by turning it off and on again, but so far nobody seems too keen to volunteer for a quick trip to the upper atmosphere.
Update 5/30: Good news! The LightSail crew has regained contact with the LightSail craft after it rebooted, and they hope to upload a software patch to prevent this kind of incident from happening again. The Planetary Society team will have more to say in the next two days.