 Haise was again scheduled to walk on the Moon as commander of Apollo 19, but Apollo 18 and Apollo 19 were canceled on September 2, 1970.Joe Engle had trained on the backup crew for Apollo 14 to explore the Moon with Cernan, but he was replaced by Schmitt on the primary crew for Apollo 17.Schmitt had previously been crewed with Apollo 12 Command Module pilot Dick Gordon in anticipation of Apollo 18, but Schmitt replaced Engle on Apollo 17 after the cancellation of Apollo 18 and Apollo 19, leaving Gordon as the last Apollo astronaut to train extensively for lunar exploration without ever landing on the Moon.