Science Advisor to the President War II by President Franklin Delano Roosevelt. Vannevar Bush chaired this office through Roosevelt's death in 1945, and continued under Roosevelt's successor Harry S. Truman until 1951. After the war, President Harry S. Truman replaced the OSRD with the Science Advisory Committee in 1951. The office was moved to the White House on November 21, 1957, by President Dwight D. Eisenhower to provide advice and recommendation in response to the Space Race started by the USSR's launch of the first artificial Earth satellite, Sputnik 1. President Richard M. Nixon eliminated the PSAC in 1973, rather than appointing a replacement for
President of the Navajo Nation to serve out his full term, then the Vice President shall act in his place for the remainder of the term, or until the President is able to resume his duties. §1006 of the Code instructs, that in the event a vacancy should "occur in the Office of President and Vice President, the Speaker shall serve as President of the Navajo Nation until a special election is held." The Speaker does not relinquish his Speaker duties whilst acting as interim President. President of the Navajo Nation The office of President of the Navajo Nation was created in 1991 following restructuring