Saturn IB
Since it flew in low Earth orbit and did not include a LM, Apollo7 was launched with the Saturn IB booster rather than the much larger and more powerful Saturn V. That Saturn IB was designated SA-205, and was the fifth Saturn IB to be flown—the earlier ones did not carry crews into space. It differed from its predecessors in that stronger propellant lines to the augmented spark igniter in the J-2 engines had been installed, so as to prevent a repetition of the early shutdown that had occurred on the uncrewed Apollo 6 flight; postflight analysis had shown that the propellant lines to the J-2 engines, also used in the Saturn V tested on Apollo6, had leaked.