Astronauts Grissom and Glenn hold discussion in Mercury Control Center

S64-10761 (1962) --- Astronauts Virgil I. (Gus) Grissom (left) and John H. Glenn Jr. hold a discussion in the Mercury Control Center during Mercury-Atlas 6 preflight activity. Glenn is the MA-6 pilot. Grissom was the pilot for the Mercury-Redstone 4 spaceflight made on July 21, 1961. Photo credit: NASA