James Webb led NASA during the 1960s, when it was gearing up to land people on the moon. After a fire killed three astronauts in 1967, he established the tradition that NASA would own up to its mistakes with transparent investigations; he was also a champion of space science in addition to human spaceflight.
In 2002, Sean O’Keefe, then the NASA administrator, announced that the next telescope would be named for Mr. Webb. Some astronomers were disappointed that it would not be named for an astronomer.