John Glenn, the first American to orbit the earth and the fifth person in space, passed away Thursday at the age of 95. The famed astronaut had been hospitalized for several weeks and was reported in declining health over the past several days. In addition to being one of America’s first astronauts, as part of the Mercury Seven group of test pilots, Glenn was also a long-serving U.S. senator, representing Ohio from 1974 until 1999. While serving in the Senate, Glenn became the oldest person to fly in space on Oct. 29, 1998, when he flew on Discovery mission STS-95. He was the last surviving member of the Mercury Seven—a group that included other legendary astronauts like Gus Grissom, Deke Slayton, and Alan Shepard.