Robert Gates becomes the new Secretary of Defense, replacing Donald H. Rumsfeld, who had served since January 2001. (It was Rumsfeld’s second tour in the post; he first served under President Gerald Ford from November 1975 to January 1977.)
Small satellites meant to improve the way the U.S. measures Earth’s magnetic field—an option to expand the military’s position, navigation, and timing enterprise—launched March 30 from Vandenberg Space Force Base, Calif.
