    Sentence 1: '" It 's probably not the  easiest. time. to come in and: take  over the shuttle program , but I look  forward to. the challenge , " Parsons  told reporters at NASA  headquarters.    Sentence 2:" It's probably not the  easiest time to come .in and. take  over the shuttle: program , "Mr.  Parsons said ‘at a news conference  at NASA headquarters.