More than 500 Iowans have already requested tickets from the U.S. Navy to witness the commissioning of the nation’s newest submarine – named for the state of Iowa. Mat Tanner, a retired Navy Chief submariner and executive director of the USS Iowa Commissioning Committee, says former Iowa First Lady Christie Vilsack is the sub’s sponsor and she’ll preside over the event, scheduled for April 5th at the Naval Submarine Base in Groton, Connecticut.