Editing Apollo 16 (section)

===Launch vehicle===
The launch vehicle which took Apollo 16 to the Moon was a [[Saturn V]], designated as AS-511. This was the eleventh Saturn V to be flown and the ninth used on crewed missions. Apollo 16's Saturn V was almost identical to Apollo 15's. One change that was made was the restoration of four [[retrorocket]]s to the [[S-IC]] first stage, meaning there would be a total of eight, as on Apollo 14 and earlier. The retrorockets were used to minimize the risk of collision between the jettisoned first stage and the Saturn V. These four retrorockets had been omitted from Apollo 15's Saturn V to save weight, but analysis of Apollo 15's flight showed that the S-IC came closer than expected after jettison, and it was feared that if there were only four rockets and one failed, there might be a collision.<ref name = "launch" />