Gene Kranz
Kranz's book, titled Failure Is Not an Option, published five years after the movie, stated, "...a creed that we all lived by: "Failure is not an option."" (with the pronoun 'we' referring to those working at "NASA's Mission Control Center"). The book has three index references for the phrase, but none of those give any indication of the phrase being apocryphal. In the 2008 Discovery Channel mini-series When We Left Earth, he appears throughout the series with his customary flattop haircut and wearing his white vest from the Apollo 13 mission (mission patch plainly visible) - a clue as to the mission for which Kranz has the greatest pride as the NASA MSC Flight Director ("Crew safety is the first priority." --Kranz).
Kranz would continue as a Flight Director through Apollo 17
Apollo 17
Apollo 17 was the eleventh and final manned mission in the American Apollo space program. Launched at 12:33 a.m. EST on December 7, 1972, with a three-member crew consisting of Commander Eugene Cernan, Command Module Pilot Ronald Evans, and Lunar Module Pilot Harrison Schmitt, Apollo 17 remains the...

, when he worked his last shift as a flight director overseeing the mission liftoff, and then was promoted to Deputy Director of NASA Mission Operations in 1974, becoming Director in 1983.