Bill Nelson is an American politician and former astronaut. He served as a U.S. Senator from Florida from 2001 to 2019. Before his time in the Senate, he was a member of the U.S. House of Representatives and held various positions in state government. Nelson is known for his work on issues such as space exploration and environmental protection. In addition to his political career, Nelson flew on the Space Shuttle Columbia in 1986, making him one of the few U.S. Senators to have traveled to space. He was also the Administrator of the National Aeronautics and Space Administration (NASA) from 2021 to 2023, where he focused on advancing space missions and technology.