President John F. Kennedy’s proposal to Congress in May 1961 to land a man on the moon before the decade’s end was met not with unified support, but resounding skepticism, borne out in a Gallup poll that showed 58 percent of respondents opposed to the lofty goal. So when Kennedy stood before 40,000 mostly young men and women 15 months later in Houston’s sun-swept Rice Stadium, he delivered a speech that was both an American mission statement and a pitch to a still dubious nation: “We choose to go to the moon in this decade and do the other things, not because they are easy but because they are hard.” Though Kennedy did not live to see it, that vision was realized through the genius and sweat of some 400,000 scientists, engineers and technicians — ten times the crowd on hand in Rice Stadium that day. Fifty years ago, the Apollo 11 mission took us farther from Earth than we had ever gone and, in doing so, brought us all closer, if only for the eight days, three hours, eighteen minutes and thirty-five seconds it took to play out. Told in their own words, this is the story of the people who turned what was once science fiction into history.

July 16: The weight of the world

Buzz Aldrin, lunar module pilot, Apollo 11: I was the last one in, so I was let off the elevator at a landing one stop below while [Neil Armstrong and Michael Collins] were taken up to the capsule. I was standing on the edge of this swing arm looking out at this rocket, and the [ocean] waves coming in quite a bit lower, and the sun gradually coming up, and it was really a very lonely and yet private, peaceful moment before getting into that wondrous white machine that was going to propel us off into history — we hoped.

Michael Collins, command module pilot, Apollo 11: Certain people either didn’t know about it or didn’t care about going to the moon, but it was of some importance to people in virtually every little corner of the globe, and I felt that very keenly, and I felt that in a negative sense as well as a positive. The negative was, “Hey, don’t screw it up.” I mean, I felt a tremendous feeling of, you know, I could make some stupid little mistake and just make the whole program look ridiculous in the eyes of the whole globe. . . . We felt the weight of the world upon us.

Robert Sieck, launch operations engineer, Kennedy Space Center: Since I was the backup engineer, I was not out at the Cape [Canaveral, in Florida, from which the spacecraft launched]. I could watch the launch with my wife and my 1-year-old daughter. The highway was absolute gridlock, and the cars and trucks weren’t trying to move. Everyone was there to watch history. The vendors were sold out of everything — no more T-shirts, caps, buttons or pins. People were pulling plugs of grass from the side of the road and stuffing them in zip-lock bags as souvenirs.

JoAnn Morgan, instrumentation controller, Kennedy Space Center: It was a wonderful countdown — I felt quite relaxed. Except when you get to the very end, the last 30 seconds, just knowing the power of the propellants on board and that those three men are sitting up there.

Sieck: When you’re in the control room for the launch count, you’re focused on the technical data. [Being outside] was like the difference between watching a sporting event on TV and being in the crowd at the stadium. People were jumping up and down, screaming and hollering, honking their horns.

Aldrin: For the thousands of people watching along the beaches of Florida and the millions who watched on television, our liftoff was ear-shattering. For us, there was a slight increase in the amount of background noise — not at all unlike the sort one notices taking off in a commercial airliner — and in less than a minute we were traveling ahead of the speed of sound.

Propelled by 7.5 million pounds of thrust at liftoff, the Saturn V rocket hurtled into the sky, shedding stages and picking up speed until it reached an escape velocity of more than 24,000 miles per hour. What remained of the craft completed one-and-a-half orbits around Earth, then, at the proper angle, re-fired its final rocket stage to achieve “translunar injection,” the long, slow burn towards the moon. On Earth, the action shifted from Launch Control in Florida to Mission Control in Houston, Texas. And though the trip to the moon would take parts of four days, it was hardly uneventful, particularly for the trio of astronauts.

July 16-19: Destination moon

Neil Armstrong, Commander, Apollo 11: The Saturn gave us one magnificent ride, both into Earth orbit and on a trajectory to the Moon.

Aldrin: Mike’s next major task, with Neil and me assisting, was to separate our command module Columbia from the Saturn third stage, turn around and connect with the lunar module Eagle, which was stored in the third stage. Eagle, by now, was exposed; its four enclosing panels had automatically come off and were drifting away. This, of course, was a critical maneuver in the flight plan. If the separation and docking did not work, we would return to Earth. There was also the possibility of an in-space collision and the subsequent decompression of our cabin, so we were still in our spacesuits as Mike separated us from the Saturn third stage.

Steve Bales, guidance officer, Mission Control: We were all in the 25- to 28-year-old range except for Gene [Kranz, flight director], who was 35. People who were drawn to NASA at the time were younger; it wasn’t as if anybody had done this particular job before. The crew, they were all 38, 39, 40 — they seemed a lot older to us. Or at least to me, anyway.

Chris Kraft, director of flight operations, Mission Control: On the way to the moon, you might say, “Well, that could be a pretty boring time.” But that’s not true. There were times when you had to do things with the fuel cells, when you had to get rid of the water in the system. You’re making sure the thermal operation of the spacecraft is being done well. On Apollo it was called barbecue mode.

Hugh Blair-Smith, software engineer, MIT Instrumentation Laboratory: For the long three days from the Earth to the moon they had to keep the spacecraft rotating just like a pig on a spit so the sun wouldn’t be concentrated on any one side.

Alan Kehlet, chief project engineer, North American Rockwell: Apollo 11 had less anomalies in their flight than any of the Apollo things, which I think was because I stole every good part I could find that went in that vehicle. When one of the vehicles had a problem and they wanted to steal my engine, I told them no, and we took it off of Spacecraft 109, which turned out to be Apollo 13.

John Llewellyn, retrofire officer, Mission Control: In those days, we didn’t have GPS and all that stuff. The crew didn’t have any of that either. They had almost the same thing Columbus had — a sextant and a star field.

Between the top-shelf technology, the skill of the on-board crew and a few in-flight course corrections courtesy of mission control, Apollo 11 found itself approaching the Moon on July 19. As planned, the craft sailed on the far side of the Moon where — out of radio contact with Mission Control — it executed a pair of expertly timed fuel burns to enter orbit. The craft remained in orbit until the next day, when Aldrin and Armstrong lowered themselves into the lunar module and prepared for their date with destiny. They were so close — yet so very far.

July 20: The descent

Gene Kranz, flight director, Mission Control: We had a security guard — this guy here is exuberant — and he comes up and says, “So ya gonna land today, Mr. Kranz?” And all of a sudden, that was different.

Kraft: It takes an awful lot of events going right to get you to the moon, let alone return. It was our first attempt at the landing and we had somehow, incredibly, reached the point where we were starting the descent for the landing.

Kranz: Everything was on track. We were ahead of the flight plan right on down the line. We had a private conference loop that was accessible only to people in the control room.

Bales: The outside world couldn’t hear it, the managers couldn’t hear it. He just talked to us.

Kranz: Basically I indicate that I believe we were born for this day, we were meant to be here. We did a great job preparing for this mission. And then I said, “I will stand behind every decision you will make. We came into this room as a team and we will leave as a team.”

Bales: Good news, the landing radar catches on at 39,000 feet. I thought my big problem for today was over. Unfortunately, it was just starting.

Aldrin: We got the first 1202 alarm. So we look at each other, and we know it’s in the guidance and navigation dictionary, but rather than try and get it out while the module is making a powered descent, Neil asked them what’s the reading on the 1202 alarm. Then we got a 1201.

Jack Garman, program support group leader, Apollo Guidance Software Section: The problem is that those program alarms set off what is called the “master caution and warning,” which is red lights and very large klaxon sounds — if you’ve ever seen submarine movies, kind of like the klaxon that goes off when they say, “Dive! Dive!” And as I gathered from after-flight readings, the heart rates for Neil Armstrong and Buzz Aldrin went up just a bit.

Charlie Duke, capsule communicator, Mission Control: I was shocked. Actually, “stunned” is a better word. I started reaching for my guidance and navigation checklist to see what a 1201 and a 1202 was. And, of course, Steve Bales knew immediately and didn’t hesitate very long to say, “We’re go on those alarms, Flight.”

Aldrin: It was the fact that the computer was in the process of solving the landing problem and at the same time we had the rendezvous radar in a powered-up condition and this tended to add an additional burden to the computer operation. Now, I don’t think either the ground people or ourselves really anticipated that this would happen. It was not a serious program alarm. It just told us that for a brief instant the computer was reaching a point of being overprogrammed or having too many jobs for it to do.

Bales: In the middle of the landing, it was almost as dangerous to try to abort with a bad computer as it was to carry on with the landing. So, balancing risk versus risk, we decided that the safest thing would be to continue to land.

So, Mission Control advised Aldrin and Armstrong to blow through the 1202 and 1201 warnings, and continue with their landing, as the lunar module was ever so slightly off course and rapidly burning through its fuel reserve.

Duke: I was looking at my trajectory plot, [and] Neil leveled off at about 400 feet and was whizzing across the surface. . . . It was far from what we had trained for and seen in the simulations. So I started getting a little nervous, and they weren’t telling us what was wrong.

Kraft: The lunar module was under automatic control as it approached the surface. Neil realized that the automatic descent would terminate in a boulder field surrounding a large rim crater. He took control of the spacecraft and steered the Eagle toward a smooth landing site.

Bob Carlton, lunar module control officer, Mission Control: On my stopwatch, I put a little piece of scotch tape and said, “OK, at this point now we’ll have 60 seconds [of fuel] left. And a little up further, we’ve got 30 seconds left. And a little further, we’ve got 0.”

Duke: I was giving a running commentary for mission control and Deke Slayton was sitting to my right. He was director of flight crew operations, and he punched me in the side and said, “Shut up, Charlie, let ’em land.”

Carlton: I was looking at the altitude and I thought, “We’re not gonna make it. There’s no way. There’s too much altitude for us to drop.” But I didn’t know we were in the crater.

As the Eagle cleared the lip of the crater, the altimeter abruptly leveled out, and Armstrong set down on flat ground. With 18 seconds showing on Carlton’s stopwatch, man had landed on the Moon.

Kranz: It took us a couple seconds to realize that we had made it. And then the people in the viewing room start stomping, and I mean just cheering and clapping and stomping their feet. I’m so tied up emotionally at this time that I literally cannot speak, and I’ve got to get my team back on track. . . . I rapped my arm on the console — and break my pencil — and finally get back on track and call my controllers to attention.

July 20-21: One giant leap

Bruce McCandless, capsule communicator, Mission Control: After they were given the “stay” call and shut down lunar-module systems, I headed for home, which was about 10 minutes away, to get a bite of dinner.

Doug Ward, NASA public affairs officer: The original plan was that they weren’t going to get out of the lunar module until the next day. They were going to get eight hours of sleep and the next quote-unquote morning go do the first extravehicular activity.

McCandless: But when I was pulling into the driveway, my wife came running out waving her arms. “They can’t sleep! Go back!” So I turned around.

Aldrin: We opened the hatch and Neil, with me as his navigator, began backing out of the tiny opening. It seemed like a small eternity before I heard Neil say, “That’s one small step for man, one giant leap for mankind.”

Armstrong: I did think about it. It was not extemporaneous, neither was it planned. It evolved during the conduct of the flight and I decided what the words would be while we were on the lunar surface just prior to leaving the LM.

McCandless: I had asked [Neil] before the mission launch several times what he was going to say on the occasion of this historic moment, setting foot on the lunar surface, and he always replied, “I’m a test pilot, I’ll probably just say how dusty it is or something like that. Don’t worry.”

Aldrin: In less than 15 minutes, I was backing awkwardly out of the hatch and onto the surface to join Neil, who, in the tradition of all tourists, had his camera ready to photograph my arrival.

Armstrong: A number of experts had, prior to the flight, predicted that a good bit of difficulty might be encountered by people attempting to work on the surface of the moon due to the variety of strange atmospheric and gravitational characteristics that would be encountered. This didn’t prove to be the case and after landing we felt very comfortable in the lunar gravity. It was, in fact, in our view preferable both to weightlessness and to the Earth’s gravity.

Aldrin: I found that a standard loping technique of one foot in front of the other worked out quite as well as we would have expected. One could also jump in more of a kangaroo fashion, two feet at a time. This seemed to work, but without quite the same degree of control of your stability as you move along. We found that we had to anticipate three to four steps ahead in comparison with the one or two steps ahead when you’re walking on the Earth.

Armstrong: The primary difficulty that we observed was that there was just far too little time to do the variety of things that we would have liked to have done. . . . We had the problem of the 5-year-old boy in a candy store.

After snagging a sample of the powdery lunar soil for study back on Earth, Armstrong and Aldrin erected a television camera, carefully raised an American flag, then, with Old Glory as a backdrop, spoke briefly with President Richard Nixon via teleconference. Closely monitoring their limited oxygen and water supplies, the duo resumed their scientific inquiries, setting up a seismometer and a reflector array, as well as harvesting more soil and rock samples, before returning to the Lunar Module. Nearly a decade in the making, man’s time on the moon lasted roughly two hours and twenty minutes.

July 21-24: Returning heroes

Aldrin: As I got down on the floor to sleep, I could see the broken head of a circuit breaker. It was the engine-arm circuit breaker — the one that’s got to be in to get electricity to turn the ascent engine on. Since it was on my side, obviously I would have to take the blame for my backpack knocking against things clumsily and breaking it off.

Hal Loden, lunar module control officer, Mission Control: That circuit breaker allowed the lunar guidance system to start the engine automatically — but there was another way to start the engine. We had redundancy. They would have had to hit a pushbutton manually at T minus zero.

Aldrin: It looked as though there was enough left to push [the breaker] in. When the time came, I just said I was going to push it in with a pen.

A lunar marooning averted, the LM’s engines roared to life for an ascent to reunite with Collins in the orbiting command module, a complex process that required precision on the parts of both the astronauts and the numbers-crunchers on the ground.

Frances “Poppy” Northcutt, NASA engineer and mathematician: You can’t communicate directly with the spacecraft when they are doing their maneuver, and you don’t have any tracking because it’s on the backside of the moon. You don’t know whether the maneuver went well or didn’t go well. You lose signal for about 30 minutes. Bad things can happen if they overburn or underburn or the burn doesn’t start on time. When they come around, it takes a few minutes for folks to tell you where the spacecraft is. Is it where it’s supposed to be? If it’s not, you might have to act quickly to get the information up there to correct their trajectory. Their onboard computer didn’t have nearly enough capacity to compute trajectories.

Blair-Smith: The lunar orbit rendezvous wasn’t that different from what the Geminis did in Earth orbit. But it was more nerve-wracking because if it didn’t work, where everybody would be left was not going to be very good for them. Deciding to do the lunar orbit rendezvous, to put the pieces back together to come home, took big, big balls.

Northcutt: If you write a computer program, it either works or it doesn’t.

It worked. The crew jettisoned the LM in the moon’s orbit, performed a burn to break free of the pull and were on their way back home. On July 24, Apollo 11 splashed down in the central Pacific, where it was met by the USS Hornet aircraft carrier, its mission accomplished.

Collins: It’s one of the questions I get asked a million times, “God, you got so close to the moon and you didn’t land. Doesn’t that really bug you?” It really does not. I honestly felt really privileged to be on Apollo 11, to have one of those three seats. I mean, there were guys in the astronaut office who would have cut my throat ear to ear to have one of those three seats.

Aldrin: We came down from the trees. We came out of the caves. We rubbed two sticks together. We made wheels. We had an automobile. Then we decided that we could fly like a bird. We dreamed of things up in the sky that were mysterious, mythical things, and we challenged ourselves to put a human on the moon. What a bodacious challenge confronting people on the surface of the Earth. And as a result of that challenge, two guys managed to walk on the surface. That’s magnificent.

Armstrong: In my own view, the important achievement of Apollo was a demonstration that humanity is not forever chained to this planet, and our visions go rather further than that, and our opportunities are unlimited.

Quotes compiled from: Popular Mechanics; Space.com; Aerospace America; NPR; Life; Associated Press; the 2017 documentary “Mission Control: The Unsung Heroes of Apollo;” and NASA’s online records.