Cassini Iapetus Flyby
Data from Cassini’s unique close encounter with the unusual large moon Iapetus yesterday will be downlinked today and tomorrow. The spacecraft went into safe mode last night, but indications are that virtually all Iapetus data is intact and the spacecraft continues to be healthy. Safe mode is entered into by a spacecraft when it encounters a situation that its software is not anticipating. When that happens the spacecraft shuts down non-essential systems and goes into a safe pointing attitude to insure power (in the case of spacecraft with solar panels) and communications with the Earth. Safe mode is our friend, and while we’d generally like to avoid it to avoid interruptions to normal operations, safe mode is just the spacecraft looking out for itself. When it’s a billion miles from home, better safe than sorry.