The Ask An Expert lecture series at the Steven F. Udvar-Hazy Center is presented every 2nd and 4th Thursday at 12:30 PM. A Museum staff member talks to the public about the history, collection, or personalities related to a specific artifact or exhibition in the Museum. Hot air balloons featured in a temporary outdoor display at the 2007 National Air and Space Museum "Become A Pilot" family day at the Udvar-Hazy Center.  Clockwise from upper left: Limelight, Indecision, Stained Glass, Sky Blue Pink.  How to attend