Mark Kelly is a former NASA astronaut and Navy pilot who flew four Space Shuttle missions before entering politics following a personal tragedy. He became a prominent gun safety advocate after his wife, former Congresswoman Gabrielle Giffords, was shot in a 2011 mass shooting in Tucson. Kelly's unique background as both a combat veteran and space explorer has given him a distinctive profile in the Senate, where he focuses on issues ranging from border security to climate change. His 2020 victory helped flip Arizona's Senate seat and cement the state's transformation into a political battleground.