By Jeffrey Kluger
Updated: July 23, 2019 4:37 PM ET

Chris Kraft scared the hell out of me — in all the right ways, yes, but still. During the Apollo program, Kraft, who died at age 95 on July 22, was NASA’s director of flight operations, and later ran the Johnson Space Center in Houston. I first met him in the early 1990s, when I was writing Apollo 13, and I thought I had a pretty good idea of what to expect. I’d heard he was blunt, profane and brilliant and did not suffer fools easily. What I actually found was that he was, well, blunt, profane and brilliant and did not suffer fools easily.

During the course of our conversation, he described someone he had once worked with at NASA as “a dumbass.” I asked him what he meant specifically by that term. He looked at me wonderingly and said, “I mean stupid! Not intelligent!”

He told me about how he had grounded Scott Carpenter, one of the Original Seven astronauts, after a single flight because he overshot his splashdown target by 250 miles, forcing the Navy to go looking for him — a mistake Kraft attributed to Carpenter’s fooling around with sightseeing and scientific observations when he should have been focused on reentry procedures. He told me too about grounding the entire Apollo 7 crew for general insubordination and indiscipline during their 11-day Earth-orbital mission. When one of the astronauts, who would surely have punched his ticket for a later trip to the moon if Apollo 7 had gone well, asked Kraft if it was really true, that he was really finished, Kraft answered, “You heard it from the horse’s mouth.” If he took pity on the busted spacemen, he didn’t show it.

But pitilessness was what space travel demanded, and still demands today. There is too much that can kill you — too much that seems almost to be trying to kill you — to give in to sentiment. Kraft understood that intuitively. A graduate of Virginia Polytechnic Institute, he went to work first for NACA, the National Advisory Committee on Aeronautics, in Hampton, Virginia, becoming one of what the locals referred to as the “Brainbusters,” the distracted-looking young geniuses who always seemed as if their minds were on much bigger things.

Or not always so big. Kraft liked to tell the story about the house he and his wife built in Hampton, after he had put enough money away from his first few years at NACA. He designed the fireplace and chimney himself, reckoning that if he knew how to master the way air moves over the wings of a hypersonic aircraft, he could certainly figure out how to make smoke go up a flue in the most efficient way possible. He handed the design off to the bricklayers and was peeved to find, a few days later, that what they built looked nothing like what he had designed.

“This isn’t right,” he told them.

“This is the way we build fireplaces all the time,” the lead bricklayer responded.

“Well it’s not the way you’re going to build mine,” Kraft snapped. “Tear the damn thing out.”

The men did what they were told and the house was left with a pile of bricks and a hole where the chimney should go — a hole that remained until Kraft could find someone to build the thing to his liking.

Read more: Dueling Superpowers, Rival Billionaires. Inside the New Race to the Moon

But there was soon far more to occupy Kraft’s mind. The Soviet Union launched Sputnik, humankind’s first artificial satellite, in 1957, firing the starting gun of the space race. The old NACA became the new NASA — the National Aeronautics and Space Administration — and Kraft was one of its founding, ranking members. He was there for the entire ride, through the early triumphs of the one-man Mercury and two-man Gemini programs; the tragedy of the Apollo 1 fire, the towering achievement of the Apollo 11 lunar landing, the near disaster of Apollo 13, and on into the shuttle era.

TIME put Kraft on the cover of the magazine’s August 17, 1965 issue, relatively early in his NASA run, when the first moon landing was still four years away, and captured both his hard, engineering edge and the flicker of poetry he still allowed himself.

The Aug. 27, 1965, cover of TIME
TIME

“Back of all Kraft’s unforgiving perfectionism,” TIME wrote, “is always the knowledge that the final decision, the final responsibility, is usually his alone. ‘He’s a virtual dictator,’ says Gene Kranz, [a] deputy flight director, ‘which is the way it has to be.’ Kraft prefers to think of himself as conductor of a symphony orchestra. ‘The conductor,’ he says, ‘can’t play all the instruments—he may not even be able to play any one of them. But he knows when the first violin should be playing, and he knows when the trumpets should be loud or soft, and when the drummer should be drumming. He mixes all this up and out comes music. That’s what we do here.'”

Certainly, Kraft did not always show that kind of marriage between hard science and soft sentiment, but he could when it counted. He deeply respected Deke Slayton, one of the Original Seven astronauts, who was declared medically ineligible for flight shortly after his selection, when doctors discovered a heart fibrillation that had escaped earlier examinations. Slayton instead became head of the astronaut office, sending other men to space and never seeming to stew over the doctors’ decision. But Kraft did stew, always believing Slayton was fit for a mission — and more than deserving of it after his heroically silent service. Periodically, he would raise the idea of assigning Slayton to a crew, but the response from the rest of the NASA brass was always the same: “Why Deke, Chris?”

It was a question without an answer. In a field in which lives turned on tiny differences in engineering and chance three or four places to the right of the decimal point, a questionable heart was not a remotely tolerable risk. Finally, in 1974, when the crew was being selected for the joint U.S.-Soviet Apollo-Soyuz mission, the final flight of an Apollo spacecraft and the final chance an aging Slayton would get, Kraft again raised the possibility of putting him aboard.

“Why Deke, Chris?” came the question once again.

This time Kraft had an answer. “Because we’ve f*cked that guy long enough, that’s why.”

On July 15, 1975, the final Apollo spacecraft left its pad at Cape Canaveral with Deke Slayton in the center seat.

Kraft’s death, like so much in his life, seemed engineered for precision. Two days earlier, the world celebrated the half-century anniversary of the Apollo 11 landing. Kraft was there to see the space age in, and he remained to see the great commemoration out. The boot prints left on the windless, rainless moon endure. Chris Kraft, in a very real sense, put them there.

Correction, July 23

The original version of this story misstated Chris Kraft’s age at the time of his death. He was 95, not 96.

Write to Jeffrey Kluger at jeffrey.kluger@time.com.

SPONSORED FINANCIAL CONTENT

Read More From TIME

EDIT POST