HOUSTON — After Gene Kranz retired in the 1990s, he started to give occasional tours to VIPs at NASA’s Johnson Space Center.
It was there in the Apollo Mission Control Center that Mr. Kranz had a view like few others during the highest highs and lowest lows of the moon race. As a flight director, he helped lead the complex human and technical operation that managed the triumph of the Apollo 11 moon landing 50 years ago. He also rallied and refocused NASA mission flight controllers after the tragedy of Apollo 1 in 1967, when Gus Grissom, Ed White and Roger B. Chafee died in a fire during a launchpad simulation.