Guion Stewart Bluford Jr. is an American aerospace engineer, retired U.S. Air Force officer and fighter pilot, and former NASA astronaut, who is the first African American and the second person of African descent after Arnaldo Tamayo Méndez to go to space. Before becoming an astronaut, he was an officer in the U.S. Air Force, where he remained while assigned to NASA, rising to the rank of colonel. He participated in four Space Shuttle flights between 1983 and 1992.