July 18, 1915: The birth of John Glenn

Today in the history of astronomy, the first American in orbit is born. | Published: July 18, 2026 John Glenn prepares to board Friendship 7 for his historic flight. Credit: NASA Born on July 18, 1921, John Glenn grew up in Ohio and joined the Marine Corps in 1943. He flew 59 combat missions in World War II and 63 in the Korean War before being selected by NASA for the Mercury program. In 1962, he spent five hours orbiting the Earth in the Friendship 7 capsule – the first American in orbit. After retiring from NASA, Glenn served as a senator for 25 years, and then in 1998 became the oldest person in space when he returned on a space shuttle mission at the age of 77. He had lobbied for the seat on the mission after contemplating the similarities between the aging process and the physical effects astronauts saw after space travel. During the flight, Glenn supplied data on brainwaves, heart rate, and temperature, as well as urine and blood tests. Elisa Neckar is senior production editor of Astronomy magazine, and the editor of the Today in the History of Astronomy feature on Astronomy.com.