WASHINGTON (Reuters) - U.S. President Donald Trump intends to nominate Michael Griffin, a former administrator of the National Aeronautics and Space Administration (NASA), as undersecretary of defense for research and engineering, the White House said on Monday. The White House had said in October that Trump intended to tap Griffin for principal deputy undersecretary of defense for acquisition, technology, and logistics. Monday’s announcement did not give a reason for the change. Griffin most recently served as chairman and chief executive officer of the Schafer Corporation, a provider of scientific, engineering, and technical services and products in the national security sector, the White House said. He held the top NASA job from 2005 to 2009. 