On August 20, Ranger 5 began the long cross-country trip from state of California to Florida and arrived there the day of Mariner 2's launch. Atlas 215D and Agena 6005 arrived later that week and prelaunch checkouts were started. Initial preparations focused on the launch vehicle itself, which was causing almost as many problems as the Ranger probes themselves. The Atlas-Agena combination malfunctioned four out of the six times that NASA had launched it and every booster that was delivered to Cape Canaveral required modifications or repair work before it could fly. Moreover, in the year between Ranger 1 and Mariner 2, there had been no improvement whatsoever in the quality control of the Atlas-Agenas. Since Ranger launches had been delayed before by booster problems, technicians rushed to make sure nothing of the sort would delay Ranger 5's mission.