George Mueller, a coolly decisive, hard-driving engineer, scientist and administrator who was given much of the credit for enabling NASA to meet President John F. Kennedy’s manned moon landing timetable, as well as for initiating the Skylab and space shuttle programs, died at his home in Irvine. He was 97.

His Oct. 12 death was announced by NASA. The cause was congestive heart failure, said Arthur Slotkin, a family spokesman.

As head of NASA’s Office of Manned Spaceflight, with the title of associate administrator, Mueller bore much of the burden of seeing to it that the space agency’s Apollo program met the challenge Kennedy issued in a celebrated 1961 address: landing a man on the moon – and bringing him back – by the end of the 1960s.

During the Cold War, a manned moon landing became a major American goal and was considered a symbol of the country’s will and determination, particularly in view of what was perceived as a space race with the archadversary of the time, the Soviet Union.

In Mueller, NASA was said to have installed in one of its top posts a man of great abilities, in both engineering and administration, and a leader who understood both rocket science and human psychology. At key moments, according to space histories, he showed himself to be adept at assessing risk and to be bold in acting on his assessments.

One of his significant contributions was what came to be known as the “all up” philosophy of rocket and spacecraft testing. As its name suggests, “all up” was a form of examining everything to be used for a space mission all at once, as opposed to incremental modes of proceeding inch by slow inch.

As applied to the space program, it implied specifically such techniques as the testing of all three stages of the giant Saturn V booster rocket while they were coupled together and with a payload attached to boot. It was reported that the scheme had its doubters, among them such leading lights of rocketry as Wernher von Braun.

But in time, the forceful Mueller proved persuasive enough to overcome all such reservations, and it was “all up” for the mammoth Saturn V, the launch vehicle upon which NASA pinned its hopes of sending Americans to the moon.

Ultimately, a NASA history read, “it is clear that without all-up testing, the first manned lunar landing could not have taken place as early as 1969,” the last year that met Kennedy’s schedule.

The same NASA history went on to say that Mueller’s “bold telescoping of the overall plan bore magnificent fruit.” Frank Borman’s Apollo 8 crew orbited the moon on Christmas 1968, and in the next year, the sixth Saturn V took Neil Armstrong’s Apollo 11 to the first manned lunar landing.

In an interview for a Smithsonian Institution publication, Mueller indicated that some of his assurance was borne of necessity.

“Well,” he told Air & Space magazine, “one thing that gave me the confidence is that there wasn’t any other way we were going to get the program done on the schedule that we had.”

But he maintained that he was not being rash in sending Apollo 8 to circle the moon after the 6.5 million-pound rocket that was to lift it into space had flown only twice, neither time carrying men aloft.

“It wouldn’t have gone if I hadn’t been comfortable,” he said. “I spent about four months that summer looking at every possible way that it could fail, and convinced myself that it wasn’t going to fail,” he said. “So we went forward with it.”

In the same interview, he observed that his sort of decision-making would no longer carry the day.

“We have too many people who believe in absolute safety,” although “there is no such thing,” he said. Moreover, he added, “if you designed your program to be absolutely safe, you’d also be sure you’d absolutely never fly.”

Yes, he suggested, he did run a risk, but it was only “a reasonable risk.” What he would have ruled out, he said, was “an unreasonable risk.” A method of distinguishing one from the other, he implied, entailed imagining the worst that could happen, and then deciding whether that danger could be overcome.

In January 1967, NASA suffered one of its most devastating setbacks to that point. Three astronauts were killed in a fire during a launch pad test. The response given then by NASA’s administrator, James E. Webb, helped show how Mueller was regarded. Despite the tragedy, Mueller would remain in his job, Webb said, because he was “one of the ablest men in the world.”

Mueller himself had something to say that was also illuminating.

“As far as I can tell,” he was quoted in an oral history, “I have a different reaction to stress than many people do.” His approach, he indicated, was not to dwell on failure, nor to let it cause him to lose heart.

Rather, he said, the proper approach was “one of taking a look at the problems and saying, now, this is what needs to be done, and then working with the people to get their thinking process going again.”

George Edwin Mueller was born in St. Louis on July 16, 1918, a few months before the end of World War I.

As a boy, he was captivated by science fiction, and he also built model airplanes powered by rubber bands. Radio was coming into vogue, and he built his own receiving sets. At what was then the Missouri School of Mines, a technical school, he studied electrical engineering and received a bachelor’s degree in 1939. He received a master’s degree, also in electrical engineering, from Purdue University in Indiana in 1940.

As a young graduate, he held jobs in which he worked on the development of microwave tubes, television and radar. He worked at Bell Labs in New Jersey and took graduate courses at Princeton University.

As an assistant professor of electrical engineering at Ohio State University, he worked toward his doctorate, receiving a Ph.D. in physics in 1951.

In the 1950s, he went to work in the aerospace industry. After joining Ramo-Wooldridge Corp., he remained there through a merger into what was to become TRW. He played an important role in the development of the intercontinental ballistic missile, and he began to formulate his “all up” program of testing.

“You don’t want to be testing piece-wise in space,” he was quoted. For complex systems, “all up” was vital, he said, because it was not possible to predict what component might fail, but with an entire system being tested, “you have a reasonable chance” of finding what had not performed.

In the 1960s, work on rockets became increasingly associated with NASA, and ultimately, Mueller was drawn in at a high level, starting as deputy associate administrator. His power and authority steadily increased.

In addition to his management of the moon program, he helped design Skylab, America’s first space station, and spoke out strongly in favor of a lower-cost, reusable launch vehicle.

The space shuttle embodied some of the concepts of reusability that he advocated.

After the moon landing, Mueller left NASA in December 1969, at what he suggested was the proper moment. Given the workings of the bureaucracy and government, he once said, “it’s clear that you have a limited time of effectiveness in Washington if you really are doing anything.”

He returned to the space industry. He was an executive with General Dynamics and then held the top posts at System Development. Later he joined and led the Kistler Aerospace, one of the private firms that has tried to develop means for launching payloads into orbit. His honors include the National Medal of Science.

Mueller’s marriage to Maude Rosenbaum ended in divorce. Survivors include his wife of 37 years, the former Darla Hix Schwartzman of Irvine; two daughters from his first marriage, Jean Porter of West Liberty, Ky., and Karen Hyvonen of Southampton, Mass.; two stepchildren whom he helped raise, Wendy Schwartzman of Calabasas and Bill Schwartzman of Villa Park; 13 grandchildren; and 13 great-grandchildren.

Beyond the competitive aspects of the space race, Mueller believed in the importance of space exploration.

“The only question,” he once said, was “whether this nation will prevail in space … or will we abandon the future to others.”

In 1967, well before the term “knowledge economy” came into common use, he urged that the space program be continued beyond Apollo.

“Today,” he argued, “knowledge, as well as guns and butter, measures the true power of modern states.” Space exploration did not impede efforts to improve life on earth, he said, but rather it “contributes to the fundamental solution of these problems.”