Apollo 1 followed by Apollo 4
New mission naming scheme
The astronauts' widows asked that Apollo 1 be reserved for the flight their husbands never made, and on April 24, 1967, Mueller, as Associate Administrator for Manned Space Flight, announced this change officially: AS-204 would be recorded as Apollo 1, "first manned Apollo Saturn flight – failed on ground test". Even though three uncrewed Apollo missions (AS-201, AS-202, and AS-203) had previously occurred, only AS-201 and AS-202 carried spacecraft. Therefore, the next mission, the first uncrewed Saturn V test flight (AS-501) would be designated Apollo 4, with all subsequent flights numbered sequentially in the order flown. The first three flights would not be renumbered, and the names Apollo 2 and Apollo 3 would officially go unused. Mueller considered AS-201 and AS-202, the first and second flights of the Apollo Block I CSM, as Apollo 2 and 3 respectively.The crewed 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 uncrewed Earth orbital test flight of the first lunar module, LM-1, in January 1968. A second uncrewed 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.