In addition to the seven Mercury astronauts, two new groups of astronauts were chosen by NASA in 1962 and 1963. Not all of the astronauts got a chance to fly a Gemini mission, however.

The Group 2 astronauts, known as "the new nine", were selected on September 17, 1962. In this group were: Neil Armstrong, Frank Borman, Charles Conrad, James Lovell, James McDivitt, Elliott See, Thomas Stafford, Edward White, and John Young.

The third group of astronauts was announced on October 17, 1963. Edwin "Buzz" Aldrin, William Anders, Charles Bassett, Alan Bean, Eugene Cernan, Roger Chaffee, Michael Collins, Walter Cunningham, Donn Eisele, Theodore Freeman, Richard Gordon, Russel Schweickart, David Scott, and Clifton Curtis "C.C." Williams made up this group.