Wondering what the difference is between the two identical Mars Exploration Rovers? Curious about a Launch Director’s job as the countdown heats up, or just how the MER-B rover, Opportunity, will handle the tasks of a robotic geologist? For answers to these questions and more, join NASA Direct! for two live webcasts highlighting launch of the Opportunity rover. Launch is currently scheduled for June 28 at 11:56:16 p.m. EDT.