Kathryn Dwyer Sullivan is an American geologist and a former NASA astronaut. A crew member on three Space Shuttle missions, she was the first American woman to walk in space on October 11, 1984. On June 7, 2020, she became the first woman to dive to the Challenger Deep in the Mariana Trench, the deepest part of the Earth's oceans. She was Under Secretary of Commerce for Oceans and Atmosphere and Administrator of the National Oceanic and Atmospheric Administration after being confirmed by the U.S. Senate on March 6, 2014. Sullivan's tenure ended on January 20, 2017, with the swearing in of President Donald Trump. Following completion of her service at NOAA, she was designated as the 2017 Charles A. Lindbergh Chair of Aerospace History at the Smithsonian Institution’s National Air and Space Museum, and has also served as a Senior Fellow at the Potomac Institute for Policy Studies.