Mercury seven astronauts participating in U.S. Airforce survival school. From left to right the astronauts are: Leroy Cooper, M. Scott Carpenter, John Glenn, Alan Shepard, Virgil Grissom, Walter Schirra and Donald Slayton. They are wearing some garments made from parachute material. This desert training was to prepare the astronauts for an emergency or faulty landing in a remote area. This group of astronauts, also known as the Original Seven and Astronaut Group 1, are the only group of astronauts to have flown on all of NASA's manned spacecraft in the 20th century. Photographed at Stead Air Force Base, Nevada, USA, in 1960.