A Wired article says that Nasa needs to swap out some brains on the Martian rovers. Nasa will toss out some software commands that are no longer needed and replace it with some more smarts to make up for a spectrometer that has already gone bad. The brain transplant will take a long time to do because it's being transmitted at the blazing rate of about 0.5k bps (for reference, your regular phone modem these days communicates at 48k to 56k baud or about 100 times faster). Other than that the Nasa rovers are in good health and should arrive at Mars sometime around the beginning of the year. This download software as ya go method is a one way Nasa saves on hardware (does that really matter that much?).