It's Friday. Sam will be seeing NPR's Susan Davis and Lulu Garcia-Navarro in the studio as they bid farewell to NASA's Opportunity Mars Rover. They're breaking down the issues raised as President Trump declares a national emergency in order to build the border wall. Also, what led more teachers — this time in Denver — to strike this week? Plus, Sue explains why she's over the TV show 'This Is Us' in a new segment.