 The manned flight hiatus allowed work to catch up on the Saturn V and Lunar Module , which were encountering their own delays . Apollo 4 flew in November 1967 . Apollo 1 's ( AS @-@ 204 ) Saturn IB rocket was taken down from Launch Complex 34 , later reassembled at Launch complex 37B and used to launch Apollo 5 , an unmanned Earth orbital test flight of the first Lunar Module LM @-@ 1 , in January 1968 . A second unmanned Saturn V AS @-@ 502 flew as Apollo 6 in April 1968 , and Grissom 's backup crew of Wally Schirra , Don Eisele , and Walter Cunningham , finally flew the orbital test mission as Apollo 7 ( AS @-@ 205 ) , in a Block II CSM in October 1968 . 
