This article, which originally ran in our July 2009 issue, appears in “To the Moon and Back,” our July 2019 collector’s issue celebrating Texas’s role in fifty years of space exploration. Subscribe today.

Great historical achievements are often taken for granted. Forty years ago, for example, on July 20, 1969, folks gathered around televisions and radios as Neil Armstrong stepped down onto the moon; they wept in public and in private; they never forgot the particulars of their experience on that day. But most people born after 1969 view the achievement as a foregone conclusion. They may never stop to consider in amazement the idea of a man in a space suit standing on the surface of the planetary satellite that humans had been staring at in wonder for tens of thousands of years. Certainly, they rarely contemplate the astounding journey that led to that first step.

On April 12, 1961, only three months after President John F. Kennedy came into office, the Russian Yuri Gagarin became the first person to orbit the earth. In response, Kennedy declared it his intention, in a speech before Congress, that the U.S. land a man on the moon before the decade was out. “No single space project in this period will be more impressive to mankind,” the president declared, “or more important for the long-range exploration of space.” The benefits wouldn’t only be political. “We needed this first moon landing to be a success,” writes astronaut Buzz Aldrin in his new book, Magnificent Desolation, “to reaffirm that the American dream was still possible in the midst of turmoil.”

The effort to realize Kennedy’s vision took eight years, about $24 billion, and 400,000 employees at some 20,000 industrial firms and universities. Wernher von Braun and his team at the Marshall Space Flight Center, in Alabama, developed the Saturn rocket and propulsion systems used in the liftoff; researchers at the Massachusetts Institute of Technology worked on the guidance and navigation computer systems; and under Kurt H. Debus, the Launch Operations Center (now the Kennedy Space Center), in Cape Canaveral, Florida, tested spacecraft and launched men into space.

At the Manned Spacecraft Center (now the Johnson Space Center), in southeast Houston, a small group of engineers with skinny ties and pocket protectors played a crucial role. They were the ones who planned, coordinated, and monitored the first lunar landing. The group was composed of mostly young men, many of whom were blessed with just enough inexperience to assume they could achieve the impossible. Their work was a triumph for Houston and all of Texas, a continuation of the frontier legacy. They are as much a part of the fabric of our story as wildcatting and ranching. It was their ingenuity that resulted in those glorious, bizarre images of Armstrong and Aldrin bounding on the lunar surface. This is their story.

A crowd, including former president Lyndon B. Johnson and Vice President Spiro Agnew, watches the rocket ascend. NASA

On May 25, 1961, President Kennedy delivered a speech before a joint session of Congress, saying, “I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth.” Acknowledging the difficulty of this charge, he added that no other space project “will be so difficult or expensive to accomplish.” He was right.

TED SORENSEN was special counsel and adviser to Kennedy. He lives in New York City. I had met with Jerome Wiesner, who was chairman of a transition task force that President-elect Kennedy had appointed to help advise him on what he should do about the space program. At that point there was no talk about a lunar landing, and I was skeptical whether the enormous amount of money for space exploration could be justified. But I do remember, quite clearly, Wiesner saying that he thought, yes, all kinds of indirect benefits might well result. I remember him turning to me and saying, “Even the secrets of the universe itself. The origin of human beings.” That convinced me.

CHRIS KRAFT was the flight director of NASA’s first manned space mission. He lives in Houston. Initially the experts’ response to the idea of landing a man on the moon was that it would be possible but that it would be a very difficult technological program, as well as very costly. But the president persisted.

SORENSEN: I was sitting there on the floor of the House when Kennedy made the speech. You can usually tell how something’s going over, and I think the initial response of all the Congress and senators sitting there was “Huh?” Kennedy, I think, sensed that there was skepticism and departed from his prepared text to tell Congress that it had to play its part and provide the money and the authority and not get too easily discouraged if things didn’t go swiftly. At no other time did he depart from his text.

KRAFT: I was asked to brief the president when he came through Houston on how we were going to go to the moon. I didn’t know a damned thing about how we were going to go to the moon. But I got with my people, like [engineers] John Mayer and Bill Tindall, and when the meeting time came, I stood up in front of Kennedy and gave him a picture of what we were gonna do.

Armstrong and Aldrin practice taking lunar samples.
Armstrong and Aldrin practice taking lunar samples.NASA

Two years after Kennedy’s speech, the Manned Spacecraft Center opened about 25 miles from downtown Houston, near Clear Lake City, at the site of a former ranch. There, a small group of engineers and researchers would figure out the nuts and bolts of how to put a man on the moon. It was a modest location for such an ambitious project. In the years that followed, the prairies were developed, but in 1969 the population of Clear Lake City was still only about four thousand. In 1963 Kraft had been named the director of flight operations at Mission Control. One of the original members of the 1958 Space Task Group, he had helped design and manage Project Mercury, the first U.S. human spaceflight program, which had succeeded in 1962 in its goal of putting an American into orbit around the earth. Mission Control grew under Kraft, who would ultimately oversee the four flight directors who worked in shifts to land a man on the moon: Gene Kranz, Glynn Lunney, Gerry Griffin, and Cliff Charlesworth (now deceased).

GERRY GRIFFIN was a flight director who assisted Apollo 11’s lead flight director, Cliff Charlesworth, during the launch and reentry phases of the mission. He lives in Hunt. If there is a father of manned spacecraft operations, it’s Chris Kraft. Gene Kranz was at his side as his assistant flight director for those Mercury flights, and so in a way they became kind of a team of leaders. No doubt, though, no doubt that Kraft was the boss.

KRAFT: My philosophy was to choose the right people to do the job, give them responsibility and authority, and then let them go do it. Now, that doesn’t mean I didn’t look at the details of what they did. I looked at the damned details every day, and the guys met with me and they told me what they were doing. I encouraged them and I busted my fanny to get what they needed.

GLYNN LUNNEY was a flight director on Gemini and Apollo and the chief of the flight director’s office in 1969. He lives in Houston. Kraft treated us very well, but he also believed you’ve gotta do it right. He had very high standards for us and yet he also lived those standards. Mostly by example, he led us to be the kind of people we actually became.

GENE KRANZ was the chief of the Flight Control Division at the Manned Spacecraft Center in 1969. On his shift as flight director, Apollo 11’s lunar module landed on the moon. He lives in Dickinson. I came on board at the very beginning of the Mercury program. I actually had to build the entire staff that turned out to be Mission Control. As a fighter pilot, there are certain characteristics you look for in people. You’re looking for a bit of cockiness, a bit of arrogance. You’re looking for a person who wants to do something rather than be something.

LUNNEY: I have to tell you that, just to be sure you know this: We were not “the best and the brightest” in the United States. Nobody selected us; we selected ourselves. And the talent ranged all over the place. Some people were very quick; other people were fairly slow and deliberate.

STEVE BALES was the guidance officer, or “guido,” during the landing phase of Apollo 11. He lives in Sewell, New Jersey. Basically we were engineers. Math and science majors. Most had graduated about 5 or 6 years before getting hired. Some had a few years of experience. Our average age was only 26 or 28. I was 26. We considered the astronaut crew fairly old, but they were only 10 or 15 years older than me.

ED FENDELL was the instrumentation and communications officer for Apollo 11. He lives in League City. When I came to work out here at NASA, I found out immediately that if you said you couldn’t do something, you disappeared.

LUNNEY: We figured out how to do all that stuff just by grinding away on it day after day. We argued about each piece of each mission vociferously. People would have different reactions during the debates. Guys would be extremely blunt, and some people would get very emotional about their positions. Sometimes it was, “You’ve impugned my honor.”

KRAFT: None of us was ever at home. My son once was asked what his father did for a living and he said, “I don’t know. He’s never home long enough for me to find out.”

LUNNEY: The work flowed in and out of the social life very easily. We’d gather up in a little gang of people for cocktail parties or whatever the hell we were doing at the time—beer and oysters in the yard, probably. And it was all about work. Guys were either arguing about specific problems or ragging on each other about what they did and how they did it.

BALES: That whole area in Clear Lake was like a prairie. It was just so remote out there. And even if there were other people, you would have a hard time talking to them. You’d talk mission, mission, mission. That’s all you cared about. There were two countries at the time. There were people like us, with the narrow ties and the white shirts, clean-shaven. And then there was a group that, God knows, was decidedly different. To us, though, it seemed like they didn’t exist. It was like the world almost didn’t exist for those years, except for what we were trying to do.

Armstrong, Michael Collins, and Aldrin pose for an official NASA portrait.
Armstrong, Michael Collins, and Aldrin pose for an official NASA portrait.NASA

The first two U.S. human spaceflight programs, projects Mercury and Gemini, wrapped up by 1966. The next phase was known as Apollo. During this time the NASA team was making enormous technological leaps. Computer, communication, and propulsion expertise advanced quickly. Probably the most important breakthrough was the strategy of lunar orbit rendezvous. According to this idea, which was first proposed in 1961, a large spacecraft and a smaller one would go together into lunar orbit, at which point they would separate, allowing the small ship to touch down on the moon’s surface while the larger one remained in orbit. After a brief period, the smaller ship would return to the larger one. For the first time, the Apollo project had a practical plan for how to land on the moon. Meanwhile, questions about the dangers astronauts might encounter when they got there began to multiply.

KRAFT: You have to realize that when the president said we were going to go to the moon, we were still novices in spaceflight. There are a lot of things that we did not know how to do. Now, it didn’t frighten me. It’s just that we were faced with enormous challenges. It was the wise thinking of a few well-placed engineers across NASA that came up with the idea of lunar orbit rendezvous. Now, that changed the picture for us. Definitely. That made it more rational, if you will. A “bug,” as we called it, would descend from a spacecraft in orbit around the moon. It would be a very light thing, and the pilot would go down there and land and get back up and rendezvous with the thing he left.

GRIFFIN: If you looked at the Saturn V rocket on a launchpad, there was a triangular cone thing on the top. That was the command module, where the crew would sit during liftoff. Behind that, we stowed the lunar module under a fairing. And what we did was, we threw that whole piece into orbit. Those shrouds that covered up the lunar module came off like big petals. And the command module separated, turned, came back, and plugged its nose back into the lunar module and extracted it off the Saturn V. And then that combination—command module and lunar module—went to the moon. When you approached the moon, then, you went into orbit using the engine in the command module. Actually it was in the service module, but think of them as one and the same. They used that engine to slow down and knock themselves into lunar orbit, and then eventually Armstrong and Aldrin stepped into the lunar module, separated from the command module, and went down and landed on the moon while [Michael] Collins stayed in orbit.

BALES: We stretched technology in so many areas. MIT had to hand-code every line. Ladies at Delco had to build the ropes—they built a memory by “knit one, pearl two.” The computer system, the worldwide communication systems, the propulsion system—everything was stretched.

KRAFT: Serious questions immediately began to arise: We don’t know what the surface of the moon is like, and so how are we going to build a landing gear to land on the surface of something we don’t fully understand? What does the surface look like? Is it all craters? Mountains? Plains? What kind of soil is it, so we can tell what the impact loads are to support the landing of a craft? Also, are there any pathogens on the moon? Are we going to kill everybody on the earth with some new bug, some new virus?

BRUCE MCCANDLESS II was an astronaut who served as Apollo 11’s capsule communicator, or “capcom,” during the moon walk. As such, he was the only person at Mission Control to communicate directly with the crew during that historic moment. He lives in Conifer, Colorado. A very prominent scientist, Thomas Gold, had predicted that based on his studies the surface of the moon could have as much as three feet of fine dust on it that astronauts would have to wade through. He believed the dust could conceal funnel-like structures, euphemistically called morning glories, into which an unsuspecting crewman could step, sink out of sight, and potentially never be seen again.

In an Apollo 1 test and training exercise on January 27, 1967, a fire caused by poor workmanship and inadequate safety design killed the entire crew: Virgil “Gus” Grissom, Ed White, and Roger Chaffee. As a result, the devastated NASA employees implemented new rules and improved quality control, and many viewed the lunar programs that followed as a crusade for the crew of Apollo 1 and for Kennedy, who had been assassinated in 1963. By early 1969 it became clear that Armstrong would be the command pilot on the first attempt to land on the moon, Apollo 11, with Aldrin piloting the lunar module and Collins piloting the command module.

CHARLIE DUKE was an astronaut who served the Apollo 11 crew as capcom during the lunar landing. He lives in New Braunfels. I think we had 42 or 43 astronauts who were flight-qualified in those days. To me, the selection process was a mystery. There weren’t any tests to take, no squares to fill—nothing like that. A grounded astronaut, Deke Slayton, our boss, would make the crew and mission announcements to the whole group, and everybody would be congratulated and we’d press on with getting the next flight launched.

KRAFT: Having done Apollo 8, 9, and 10, I think then we began to have a pretty strong feeling that 11 was going to be the one that would land on the moon.

And I think we knew that Armstrong, Aldrin, and Collins would be the crew that would get the first chance.

DUKE: We were always supportive of a crew when their mission was announced. It was a real fraternity in the astronaut office in those days. I didn’t sense any animosity, any of what I would call behind-the-back maneuvering.

JAY BARBREE is a longtime space correspondent for NBC. He lives in Merritt Island, Florida. Now, it has been alleged by people in the media who do not know better that Buzz was to be the first man on the moon. That never was the case. Deke Slayton, the chief astronaut, told me this with his own lips. From the get-go the whole idea was that the commander would be the first guy to go on the moon, because once you open the hatch you need the lunar module pilot on station monitoring all the lunar module systems to make sure they are operating with the hatch open. And Aldrin was the lunar module pilot.

KRAFT: The decision about who would be first was made by [director of the Manned Spacecraft Center] Dr. [Robert] Gilruth, [Apollo manager] George Low, Chris Kraft, and Deke Slayton. Now, I had a lot to do with that, but that’s as far as I want to go.

BUZZ ALDRIN was the lunar module pilot of Apollo 11. He lives in Los Angeles, California. The crew’s relationship was reserved and, I think, natural. I was in a position of looking at what was going on, making comments on it, but on the receiving end a good bit. Not being the commander of the mission, I generally followed suit.

NEIL ARMSTRONG was the commander of Apollo 11. He lives in Lebanon, Ohio. In both test-flying and spaceflight, the crews are doing things that have never been done before. Because there is no one who has done it, there is no one who can completely train them. There are, however, many qualified individuals who can provide useful and applicable knowledge.

DUKE: Let’s say we’d start at eight in the morning. The astronauts might have four hours in a simulator, then four hours in space suit training, then everybody would work out for an hour or so, eat, and then, generally, attend an evening lecture from some lunar orbit photography expert like Farouk El-Baz or a geologist. So that would bring us to nine. Thirteen-hour days.

KRAFT: Several weeks before the flight we were at the Cape, and I remember George Low asked Armstrong, “Have you been thinking about what you are going to say when you get out of the spacecraft?” and Armstrong said, “Yes.” He wouldn’t go any further than that, and George had to drop it.

MCCANDLESS: I asked Neil four or five times what his first words were going to be. His answer was always, “Aw, gee, you know, I’m an engineer and test pilot. I’ll probably just say, ‘Sure is dusty up here.’ ”

The astronauts prepare for a helicopter to pick them up shortly after splashdown in the Pacific Ocean southwest of Hawaii.
The astronauts prepare for a helicopter to pick them up shortly after splashdown in the Pacific Ocean southwest of Hawaii.NASA

While Apollo 10 was performing a dress rehearsal for the moon landing in May 1969, Apollo 11 training was already under way. In the weeks before liftoff, the Mission Control crew and the astronaut crew went through a series of simulations that would prepare them for any problems.

KRANZ: The principal objective in the early training is to just get the feel for the planning, the crew, and the timing of the mission. If we messed up, we’d debrief, learn to do things a different way, go back and look at the mission rules, et cetera.

DICK KOOS was the lead simulation supervisor, or “simsup,” for Apollo 11. He lives in Davenport, Iowa. We could link the crew members in the cockpit simulator with the control center. The simulator had a computer just like it did on board the real spacecraft. So if they uplinked anything to a computer onboard, then it would work just like it would in flight.

BOB CARLTON was the flight controller and the guidance and control section head in 1969. He lives in La Porte. Sim guys didn’t know they did this, but they would give themselves away a lot of the time. Their room was off to the right of us, behind a window, and you could see the tops of their heads when they were sitting down behind their consoles. If they were going to slip you a big problem, you’d see their heads come up over the top of the consoles looking at you, and you knew you’d better get ready right there quick. I’d tell my backroom team, “Brace yourselves. It’s coming!”

KRANZ: Normally, the final training session is sort of a graduation exercise. You want to leave with a good taste in your mouth. But as we were approaching the end of the training period, I think Koos felt that maybe we were getting a little too cocky for our britches, so he really wanted to put us to the fire.

BALES: About seven minutes into the simulation we started to get this strange computer alarm. These were the kinds of alarms that were never supposed to happen during operation. MIT had put them in for their own purposes mostly, and I finally used the old adage “If you don’t know what’s going on, you’re better to not keep going on.” And I said, “Let’s abort.”

KRANZ: The debrief after a simulation is sort of like a Catholic going to confession. The flight director starts and then each one of the controllers takes his turn. And then the simsup, Dick Koos, gives his analysis. On this particular occasion, he said, “You know, you violated one of your principal rules of flight control: You’ve gotta have two cues in order to abort. You aborted the landing based on only one cue, which is what you were seeing in telemetry. You didn’t look for that second cue, so you screwed up.” This was bloody. You don’t screw up in final training.

BALES: We had so many things to do. We were two or three weeks from flying. You can imagine everybody had concerns and issues with what we were studying. I was almost ready to just say, “Look, this is too far down on the priority list and we shouldn’t be working on it.” And Gene said, “I want you to come up with some rules on these kind of alarms.” I told him that we had a billion things to do and I was way behind on this and that, but he said, “You find a way to get it done.” So I got together with [software engineer] Jack Garman, who was in his early twenties at the time, and together we wrote the rules.

Apollo 11 clears the launch tower during takeoff, on July 16.NASA

On July 16, 1969, at dawn, the Apollo 11 crew settled into their seats on top of the Saturn V launch vehicle at Cape Canaveral, Florida. Millions of people around the world watched the television broadcast as the 36-story rocket blasted off the launchpad at 9:32 a.m. eastern daylight time. At 12:22 p.m., on its second trip around the earth, the booster blasted the astronauts out of planetary orbit and toward the moon at an initial speed of 24,200 miles per hour. They would continue along this trajectory for the next three days.

KRAFT: George Low and I came up with an overall probability of the success of the total mission of about 56 percent. Now, I think the chances we could get the astronauts back safely was about 98 percent. We were as confident as you could be about that. I mean, let’s face it, if I told you we were 100 percent confident, I’d be lying.

JIM LOVELL was the command module pilot on Apollo 8, the first manned mission to go around the moon, and the commander of Apollo 13. He served as Armstrong’s backup on Apollo 11. He lives near Chicago. The Saturn V rocket is filled with 5.5 million pounds of high explosives. Only the crew and a few nervous checkout people are around the rocket. The rest of us are a comfortable three and a half miles away while they get strapped in. Then they’re by themselves for a while and the checkout people leave and join us, and then we have the final countdown.

ALDRIN: I paused on the elevator three fourths of the way to the top of the rocket for maybe twenty or thirty minutes while the other two astronauts were put into the cockpit. I looked down and out at the waves coming in and the red sun beginning to rise. Off to the west, I could see the different gatherings of people, and, of course, I was twenty or thirty feet away from the edge of the rocket. The frost was beginning to come off the parts that were housing the liquid hydrogen and liquid oxygen.

GRIFFIN: For three guys in this cone-shaped vehicle, it was tight. The seats would fold down and the three of them could move around in it okay, but you had to be pretty good friends to move around in the command module.

ARMSTRONG: Guenter [Wendt, the legendary launchpad leader] always had a little gift and a few encouraging words. Of course, inside our suits with the helmet visors closed, our communication was limited. He gave us a “key to the moon” and I gave him a “ticket” for interplanetary flight. Our suit technician would complete his final checks of our suits’ pneumatic and electrical connections; one of our backup crew would double-check all of the control and switch positions that we could not reach, then exit the spacecraft. Finally Guenter’s guys would do the hatch closure. At that point, we hoped that no late-occurring system problems would cause an abort, requiring us to go through all those procedures in reverse.

LOVELL: Being Armstrong’s backup, I helped him get ready. Then, when my duties were done and they were all in, I went down to the beach, where I was assigned to escort Charles Lindbergh during the liftoff.

ALDRIN: A lot of people wanted different souvenir items to be left on the moon. It was officially established that we would leave certain things, for example a special silicon disk etched with 73 messages from different leaders around the world. That was to be left on the surface along with a commemorative patch from the Apollo 1 crew, which included my very good friend Ed White, who was killed in that fire. Also, we left medals that commemorated Soviet cosmonauts Yuri Gagarin and Vladimir Komarov. And I had suggested that we leave one more item: a gold replica of an olive branch. So we had all those items in the spacecraft.

GRIFFIN: Unlike the shuttle, which kind of leaps off the pad, Saturn was a very slow accelerator because it weighed seven million pounds or something. I never did think it was going to get to the top of the tower and get clear of everything.

ALDRIN: Once we were on the way, coasting to the moon, we weren’t thrusting at all; it’s just a spacecraft that’s on a trajectory coasting out from the earth, toward the moon. We took off our helmets, gloves, and space suits and put on inside garments that were more comfortable.

GRIFFIN: The uphill ride was fine. We got the lunar module extracted and docked onto the front end of the command module, and after that it was pretty much a piece of cake until we got to the moon.

ALDRIN: The ride up wasn’t too loud. An airplane is kind of loud but you get used to it. The same way with the spacecraft. So you’re able to sleep reasonably well. There was certainly enough room, unless you felt you needed to thrash around. We were inside a very loose netting, sort of like a hammock, underneath the couches. There was enough room to get down there and to be in a position to be relatively still for six or seven hours.

At 1:28 p.m. on Saturday, July 19, the crew traveled behind the moon and inserted the spacecraft into lunar orbit. Twenty-four hours later, Armstrong and Aldrin separated the lunar module, Eagle, from the command module, Columbia, and prepared for descent. At 4:05 p.m., Armstrong took over manual control, and thirteen minutes later, the Eagle touched down at Tranquility Base.

KRANZ: On Sunday I arrived and hit my parking spot. Moody, one of the security people, says, “Well, Mr. Kranz, are we gonna be go?” And all of a sudden I realized I had just driven through a bunch of stoplights. I’d been on autopilot. You walk into the ops room and the room has its own smell. The smell is like burned coffee, pizza—and then most everybody smoked, so you had the overlaying cigarette smoke on top of that. No matter how much they tried to circulate the air, it seemed to just hang there. You walk up to the flight director’s console. Lunney’s log said no big issues, it’s all peanuts. Then all of a sudden, your team is in charge.

ALDRIN: When we were in lunar orbit, we got in our suits that morning, and I went in the lunar module first to check different things out, and then Neil came in, and together we got ready to allow the command module to maneuver the two spacecraft in the proper position to separate.

DUKE: The lunar module looks flimsy when it’s unpressurized. It’s sort of like a soda can—it feels soft, you can crinkle it, but when it’s pressurized, it’s real strong. The crew quarters had two main windows that were triangular in shape; the interior basically looked like a cockpit of an airplane except there were no seats—with one sixth gravity you needed no seats. There was a door under the instrument panel that we opened and we could climb out and land on the porch and go down the ladder onto the footpad.

BALES: When the spacecraft goes behind the moon, we lose the signal for about thirty minutes. About fifteen minutes before the signal came back, Gene said something I will never, ever forget.

KRANZ: I decided it was time for me to tell the crew how important this was, but most importantly, how I felt about them as individuals and as a team. I believed that every person in that room, from the day he was born, had something in his DNA that had brought him to that place. So I told the people, “You were meant to be in this place. You’re a great team, one that will take us to the moon.”

BALES: You cannot imagine how critical that was. Kranz knew there were going to be some things beyond our control. We could make a judgment error, and for the rest of our lives it could be terrible. Nobody knew who would get the problem; we were all praying, first, that it doesn’t happen to anybody, and if it does, let it happen to somebody else.

KRANZ: The key points were, whatever decision you make today, I will stand behind every decision you will make. We came into this room as a team, and we will leave it as a team. And those thoughts were very important to convey to my controllers, because we would lock the door moments later and that door wouldn’t be reopened until one of three things happened: We landed on the moon, we aborted the landing, or we crashed. Those were the only three outcomes in the next forty minutes.

ALDRIN: Collins sort of looked us over as we rotated around, checking everything. Then we made a slight separation maneuver, about an orbit before we started the main engine, the descent engine, to make a maneuver that would put us in an elliptical orbit. At about 30,000 feet, after looking down at the surface, we yawed around and pitched forward a little bit so we could just barely see around the rims of the two triangular windscreens. That was to position the landing radar and the rear bottom of the spacecraft so that it could get signals from the lunar surface as to what our altitude and velocity was.

KRANZ: The computer has an imperfect knowledge of its altitude. We give it the best we can from Earth, but in order to land on the moon, we’ve got to really nail down the elevation above the surface of the moon. So we’re looking for this landing radar data to come in because if we didn’t get it, we couldn’t land. And we were waiting for it. About that time we had our first computer program alarm.

ALDRIN: The additional workload on the computer evidently caused a caution light to come on—a computer program alarm. Number 1202. So we needed to find out the reason for that alarm.

BALES: I couldn’t remember what a 1202 was. I couldn’t even remember what class it was in.

ALDRIN: I think they had some idea in Mission Control that the alarm was something similar to one we had seen before. But I was certainly in the dark about it.

BALES: It took about twenty seconds for us to figure out what to do. People say, “That’s so fast,” and I say, “That’s an eternity.” You listen to the tapes: It’s an eternity. Five seconds or less is a normal response time. So when you listen to the tapes, it sounds like something is wrong, really wrong.

KRAFT: We were apprehensive as hell, and anyone who says differently is a liar.

BALES: Jack Garman was screaming, “Steve, it’s the class that if it doesn’t keep going on, we’ll be okay.” That triggered my mind. And then I looked quickly and saw the altitude was still good and I told Gene, “We’re go on that alarm.”

ALDRIN: We were quite willing to accept the same status that they did, that the alarm was okay as long as it didn’t keep flashing on all the time.

KRANZ: We keep driving in and the radar comes in and by now we’ve identified that we will be landing long. We know they’re going to have to pick through a boulder field of craters. And as we get down toward the surface, indications get pretty good by now. We’ve worked around the computer program alarms that keep appearing periodically. The landing radar looks good. The crew takes over manual control from the autopilot.

ARMSTRONG: “Barnyard math” was used during the initial phase of the powered descent. On Earth, sea level and mountaintop heights are known. On the moon, the height of the surface above the moon’s equivalent of mean sea level was far from accurate. Earth-based radar information could provide accurate knowledge of the lunar module’s height above the center of the moon, but there was a good deal of uncertainty about the actual height of the lunar module above the surface. We were required to be within approximately 5,000 feet of our 50,000-foot reference altitude for our descent guidance system to converge to a solution. We knew our velocity over the moon’s surface and could measure our angular velocity over a point on the surface by timing the passage of a lunar crater over a scale etched on my window. That permitted us to calculate our altitude above the surface. Our calculations indicated we were well within the limits.

BALES: At about four thousand feet I relaxed a little bit because the computer alarms weren’t going to stop us.

ARMSTRONG: I noted that we were reaching certain craters a few seconds early, indicating that we would probably reach the final descent point somewhat west of our intended landing point.

KRAFT: But then when they got to the point where they started hovering, we became concerned as hell because we thought they were going to run out of fuel.

CARLTON: We were assured we would never see the fuel get that low. We were told over and over to quit worrying about it. But you better believe I worried about it. At the time we got to “low level,” we were over this crater and we were looking at the altitude and I was thinking, “We don’t have a prayer.”

KRANZ: After we call “low level,” we stop measuring the fuel that’s in the tank, and it’s only our best guess. So we had a guy in the back room with a couple of stopwatches. One of my controllers in the front room, Bob Carlton, called off, “Sixty seconds!”

CARLTON: Kranz has made the observation over the years that I sounded droll. But I wasn’t as calm as I sounded. Earlier Bales had exploded during the status check for the powered descent burn initiation, shouting, “Go!” and since I was one row in front of Kranz and two consoles to the right, I could hear him chuckling across the airwaves. It sort of relieved the tension, I think, for all of us. I told myself, “Self, you’re not gonna explode like that. I know you feel that way, but don’t you do it.”

DUKE: They had sixty seconds to land or we would call an abort. Now, whether they would abort—that was up to Neil Armstrong.

ARMSTRONG: Abort recommendations would not be given lightly. Many abort maneuvers involve considerable risk, particularly those at low altitude over the lunar surface, where an abort maneuver would require shutting down the descent engine, exploding pyrotechnic charges to separate the ascent stage from the descent stage, and igniting the ascent engine, all before colliding with the surface. Ideally, there would be time to coordinate such a decision between Mission Control and the spacecraft. Were that not the case, the commander would have the obligation to make the decision based on the best information available at the time.

DUKE: I had been talking a lot, telling them, “Systems are go,” “This is go,” “That’s go.” Probably a minute or two before landing, Deke Slayton turned to me and said, “Shut up.” I’m not sure he used those words, but that’s the way it came across to me. Basically, “Cool it. Let them land.” And it was just necessary calls from that point on, fuel calls.

CARLTON: As we were coming down to thirty seconds, I was watching the stopwatch, looking occasionally at the landing radar, which was high because we were still over the crater.

DUKE: The tension in Mission Control had built to the maximum, and it was dead silent. I called thirty seconds.

FENDELL: I actually felt like I was levitating off my chair.

CARLTON: They pulled onto the flat plateau, but by that time I was looking at the watch, ignoring the landing radar.

KRANZ: And we heard, “Picking up some dust.”

DUKE: Thirteen seconds later I heard Buzz Aldrin say, “Engine stop.”

KRANZ: Then we heard, “Houston, Tranquility Base here. The Eagle has landed.”

DUKE: I responded, “Roger, Tranquility”—I was so excited it started to come out “twang-quility”—“we copy you on the ground. You got a bunch of guys about to turn blue. We’re breathing again.”

KRAFT: I think that described the situation pretty damn well.

A 70mm handheld camera image of the Sea of Tranquility’s lunar surface on July 20, 1969.NASA

At 10:56 p.m. Armstrong stepped onto the moon’s surface and uttered his famous words, “That’s one small step for a man, one giant leap for mankind.” Aldrin took photos from inside the Eagle. “It has a stark beauty all its own,” Armstrong said as he stepped around the base of the ladder. “It’s like much of the high desert of the United States.”

KRANZ: We had to get on now with a very quick appraisal of the spacecraft to see if it was safe to stay there, and if it wasn’t safe, we had to get off within two minutes. So while everybody’s cheering and applauding I needed to put things back in order.

MCCANDLESS: I was assigned to capcom specifically for the extra-vehicular-activity phase following the landing. There was a period of a couple of minutes following the touchdown during which the systems operators and crew surveyed the situation to make sure it was stable. The call was a “stay” on the lunar surface. And then Buzz and Neil were supposed to take a two-hour nap. That was the plan.

KRAFT: Once we got there and the systems were all okay, Armstrong asked if he could continue on. Frankly, I thought he would ask that from the get-go. I couldn’t see him going to sleep there. You wanted him to sleep, but if it was me, I couldn’t go to sleep.

ALDRIN: The symbolism of the flight was important to me, and I decided that at that time I would serve myself Communion. This had been approved, though I was cautioned by Deke Slayton not to say anything specifically about what I was doing. Instead, I just encouraged everyone to give thanks in their own way.

MCCANDLESS: After the initial checklist was done, Armstrong got out on the porch and deployed the TV camera. At that point we got a signal. We saw a white blob descending the ladder, and that was Neil.

GRIFFIN: The image was awful. It was very grainy, and he was kind of—it was almost like a negative instead of a positive photo.

KRAFT: Looking at that picture was surreal, no question about it. That looked like a sci-fi movie, like a silent movie.

LOVELL: It was mixed emotions. Naturally, all the astronauts wanted to be the first to land on the moon. I was Neil’s backup, but he was too healthy! So we didn’t get a chance. But we all celebrated because we had honored President Kennedy’s commitment to get to the moon before the end of the decade. We certainly had done that.

SORENSEN: I pressed my nose to the television screen to see that dim, foggy picture as best I could, and tears came to my eyes wishing that JFK were alive to see that moment when one of his boldest proposals came to pass.

MCCANDLESS: Of course, Armstrong had a well-prepared historic statement to make: “One small step for a man, one giant leap for mankind.” His communications were just noisy enough that at the time I couldn’t tell whether he said “man” or “a man,” and, of course, all the news media were jumping on me, wanting to know exactly what he’d said.

JERRY BOSTICK was chief of the Flight Dynamics Branch of the Manned Spacecraft Center in 1969. He lives in Meadowlakes. Pete Conrad, the commander of the next Apollo flight, was sitting next to me, and when Neil stepped out and said his famous words, Pete looked at me and said, “What’d he say?” I said, “Something about a giant leap for mankind.” And he said, “Now, that’s just like Armstrong”—to say something profound. I don’t know how he could have come up with anything better to say.

Officials at the Manned Spacecraft Center, outside Houston, erupt in celebration after the astronauts return safely to Earth. NASA

At 11:11 p.m. Aldrin stepped down the ladder, and in the next two hours and fifteen minutes, he and Armstrong set up their experiments and collected as many samples of lunar soil as time allowed. At 11:41 p.m. the astronauts erected a three-by-five-foot nylon U.S. flag on the moon’s surface. After that they took a telephone call from President Richard Nixon.

ALDRIN: We did the best we could to make the flag upright while we were there. You couldn’t get the pole in more than two or three inches. So that wasn’t very much to hold up a pole.

BOSTICK: The American flag was flying on the moon. How much better can it get?

MCCANDLESS: President Nixon had called fairly early in the EVA [extra-vehicular activity], wanting to talk to Neil and Buzz, and we basically put him off until the midpoint. The White House kept calling and asking when the president could talk to them. Based on our assessment of the situation, after an hour or so we said we were feeling comfortable enough on the timeline that we could accommodate the president, and so the president said a few words, and as far as we could tell everybody was happy.

HARRISON “JACK” SCHMITT was an astronaut with a background in geology who acted as the crew’s liaison to the press and the scientific community on science issues. He lives in Albuquerque. Neil Armstrong was very quiet, and we couldn’t tell what he was doing for us for about twenty minutes. Buzz was talking and running back and forth so the camera could see him, these types of things. A number of us were wondering what Neil was doing. It turned out Neil was out of view of the camera and collecting rocks, and he brought back a fine collection of lunar samples.

ALDRIN: I felt it was useful to demonstrate the mobility that a person really had, so instead of just walking from one place to another I was changing directions and sort of jogging in front of the camera for maybe thirty seconds, I guess.

BARBREE: The only photo of Neil Armstrong on the surface of the moon is a reflection of himself taking a picture of Buzz Aldrin in his face mask. So a lot of people said Buzz was so mad that he didn’t get to step on the moon first that he refused to take a picture of Neil. That is not true. Neil said there were not any pictures of him because Neil had the camera—that was his assignment, and Buzz’s assignment was to set up the experiments.

MCCANDLESS: We didn’t expect that the pressure suit boot prints would be so clearly revealed in 3-D relief on the lunar surface. The tracks—particularly the first one or two we saw—were really dramatic.

ALDRIN: You’d always like to let certain parts be a little longer, but we were operating on a predetermined time, calculated on how much oxygen and how much water and other supplies that we had, so we had to move on to stay within those limits.

ARMSTRONG: We knew we would be fully occupied throughout our surface work. We also knew that there might be unexpected events or observations that could distract us. We tried to work at a steady pace consistent with our practice sessions on Earth. The time went by quickly, but we were able to get most all of our planned work done.

Back home, the Apollo crew was feted with a ticker tape parade in New York City on August 13, 1969.
Back home, the Apollo crew was feted with a ticker tape parade in New York City on August 13, 1969.NASA

After entering the lunar module and reconnecting with the command module orbiting above, the crew cut the lunar module loose and started the journey home. Three days later, on July 24, they entered Earth’s vicinity at a speed of about 25,000 miles per hour. At 12:51 p.m. they splashed down in the Pacific Ocean southwest of Hawaii. Finally, with the crew home safely, the team who had worked on this project for many years was able to celebrate.

FENDELL: After my shift, I went home to my apartment on the Gulf Freeway and I slept for three or four hours, and on the way back to work I stopped at one of those old Dutch Kettles to get some breakfast. I was sitting up at one of those round stools at the counter and I had brought one of the papers. It was this big, thick paper with the headline “Landing on the Moon,” and I’m sitting there and these two guys walk in and sit next to me with gas station coveralls on. They start talking and one says to the other, “I landed at Normandy on D-day, and I went all through Europe in World War II, but I never felt so proud to be an American as I did yesterday.” And I put my money down, went out to my car, and sat down and cried. It hit me what we had done.

BOSTICK: I’ll tell you how momentous it was for me. My whole life is divided before July 20, 1969, and after July 20, 1969. When I hear a date, my first thought is “Okay, was that before or after we landed on the moon?”

BALES: There must have been twenty parties going on at every hotel in the Clear Lake area.

ALDRIN: The entire world was responding to our arrival back home. And that’s a little bit hard to grasp, and that’s why I felt, “Gee, that’s unusual. Is there something cute I can say about that?” So I tapped Neil on the shoulder and said, “Look, we missed the whole thing.”

BALES: Some of the guys are gone now. Most of us will be gone before the next lunar landing. At 66, you realize that it was the people, not the event.

KRANZ: You gotta hold your emotions in check and in check and check and check. And it always seemed they always poured out when the mission was over. The emotional release is so intense at that time. It takes an awful lot to be professional about it. I see that picture of the crew putting the flag on the surface of the moon and I’m so damn proud of them.

BALES: Now, what if it had all turned out badly? We’d still be criticized for the terrible way we did it. Making good decisions doesn’t always get good results, and if you get good results, it’s not necessarily due to good decisions.

LUNNEY: We were lucky. We were lucky, for example, that the damn tank that blew up on Apollo 13 didn’t show up on Apollo 11. I mean, imagine the political reaction.

ARMSTRONG: Progress in flight has been the product of those individuals who had a passion for leaving the surface of the earth, from Daedalus to the Montgolfier brothers to Lilienthal to the Wright brothers to Tsiolkovsky and Goddard. Spaceflight was made possible by two twentieth-century inventions, the liquid-fueled rocket and the electronic computer. But it was the aeronautical industry that developed spaceflight. The space expeditions, manned and unmanned, now and in the future, are and will be integral components of the continuum of flight.

KRAFT: How the hell did we do it? I mean, my God, when we first started thinking about how to fly a man into orbit around the earth, 95 percent of the guys said we couldn’t. It was incredible to do what we did. The impact that we had . . . it flat changed the world.