According to an update posted on the Athena website by Steve Squyres this morning, the Mars Odyssey orbiter has gone in to safe mode, meaning that it has detected some problem that is serious enough to cause it to cease performing its commanded operations and work in a state of low activity until it receives further instructions from Earth. Don't fear a repeat of what happened to Mars Global Surveyor! Spacecraft do go in to safe mode from time to time, and the situation is usually sorted out in a few days. Steve suggests that the safe mode was caused by the major solar activity that's taking place right now: a sunspot called "region 930" is ejecting flares and generally making life difficult for a lot of spacecraft.
The reason that Steve is concerned about this is that Odyssey represents Spirit and Opportunity's main link to Earth, so there won't be a lot of new data coming down from the rovers until Odyssey is brought back online. This is unfortunate timing, because Mars is currently just about as distant from Earth as it can be, which meant that the bandwidth available for the rovers was already at just about at its lowest level. At the same time, Opportunity is exploring Victoria crater, trying to capture as many panoramic images as possible from each cape before driving around to the next cape. It's not fair! I hope that the safing of Odyssey doesn't cost us too many hard-won rover images.
Want to know what's going on with the Sun? Check out NOAA's Space Weather website.