Complex sentence: Sean O'Keefe (born January 27,1956) is the CEO of EADS North America, a subsidiary of the European aerospace firm EADS and a former Administrator of NASA, leading the space agency from December 2001 to February 2005.
Split into simpler sentences: Sean O'Keefe (born January 27,1956) is the CEO of EADS North America, a subsidiary of the European aerospace firm EADS. He is also a former Administrator of NASA, leading the space agency from December 2001 to February 2005.