I'd appreciate suggestions on transportation from Luxembourg to Frankfurt airport (FRA). My son will be staying in Luxembourg with cousins and then flies home July 16th, flight at 11:20am. Is it possible to get to FRA using public transport that early in the morning (assume he needs to be at the airport no later than 9am)? Is the best bet a train (or trains) or bus? I know it's only a 2 hour drive, but I don't want to ask our relatives to drive him on a weekday when they must work. Many thanks.