Page "Apollo 16" Paragraph 4

Although not officially announced, the original backup crew consisted of Fred Haise ( CDR ), William R. Pogue ( CMP ) and Gerald Carr ( LMP ) who were targeted for the prime crew assignment on Apollo 19.

However, after the cancellations of Apollo 18 and Apollo 19 were finalized in September 1970 it meant that this crew would not rotate to a lunar mission as planned.

Subsequently, Roosa and Mitchell were recycled to serve as members of the backup crew after returning from Apollo 14, while Pogue and Carr were re-assigned to the Skylab program where they later flew on Skylab 4.