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This was the most famous stage in history. When Neil Armstrong's boot hit the lunar ground on July 20, 1969, the event was celebrated around the world as a triumph for humanity. And yet, broadcast television images broadcast from space have failed to convey the true daring – the enormous risks, the technological complexity, the complex teamwork – of the mission that has put two Americans on the moon.
Popular Mechanics set out to document the complete and unvarnished story. July 16, 1969 marks the first day of the historic mission. Here, insomnia journalists and operations engineers, flight directors and astronauts take us to the point where the rocket leaves the tower and responsibility shifts from Launch Control to Cape Kennedy to Mission Control at Houston for the Coast of the Crew to the Moon
[19659002] * Additional report of Davin Coburn, Adam Hadhazy, Joe P. Hasler, Erika Check Hayden, Clara Moskowitz, David Noland and Elizabeth Svoboda
** This article was published in the June 2009 issue of Popular Mechanics to Celebrate the 40th Anniversary of Apollo 11 . Since then, the first man on the moon Neil Armstrong has died in 2012. A new biopic starring Ryan Gosling as Armstrong, named First Man arrives at the cinema in October 2018.
Advertisement – Continue Reading Below [19659007] JULY 16, 1969: LAUNCH DAY
* JoAnn Morgan, [19659011] Controller of Instrumentation, Apollo Launch Control, Kennedy Space Center: The buffer at night was simply magnificent to see with all the vehicle bathed in these giant xenon lights. Because I arrived before 3 o'clock in the morning, it was near the end of the propellant charge; there was a small ventilation of liquid oxygen. It was just an enchanting sight to behold, and I had the most positive feeling that this launch was going to be successful from the moment I parked my car and climbed up to the shooting room.
* Jackie Smith, [19659011] Engineer Test Operations and Launch of Spacecraft, Kennedy Space Center: The launch days were always a little out of the ordinary because you were getting up in the middle of the night and you were going to work
* Jay Barbree, correspondent, NBC News: I was distributing radio spots until around midnight So I never went home – I slept on a camp bed at Press Site 39.
* ] Morgan: As an instrumentation controller, I was monitoring everything on the pad. It's an extremely intense job. When you go through the countdown and the launch, you are very focused. Everything is planned – it's like a script in a play
* Smith: In the world of spaceships, we had no sequence like that of launchers. We needed to make sure our systems were up and running properly. Otherwise, we had to call timeout.
* William Lucas, Program Development Director, Marshall Space Flight Center: I was very tense. We knew that there were thousands of pieces that had to work, otherwise we would have serious problems. And we knew that once we had given the ignition signal, we had nothing left to do.
* Buzz Aldrin, Lunar Module Pilot, Apollo 11: I was the last one inside, so I was let down from the # 39, lift to a stop below, while [Neil Armstrong and Michael Collins] were taken to the capsule. I was standing at the edge of that swivel arm that was looking at that rocket, and the waves [ocean] were coming down a little bit, and the sun was rising gradually, and it was really a very lonely and yet private, peaceful moment before get into this wonderful white machine that would propel us into the story – we hoped for it.
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* Morgan: Then astronauts Deke Slayton and Alan Shepard came in and they sat right behind me at the launch control. You knew when Deke and Alan showed up at the launch check that the flight crew was ready.
* Robert Sieck, Engineer of space tests and launching, Kennedy Space Center: Engineer, I was not in Cape Town. I could watch the launch with my wife and my daughter a year. The highway was completely blocked, and cars and trucks were not trying to move. Everyone was there to watch the story. The sellers were sold from everything – no more T-shirts, caps, buttons or pins. People were pulling bits of grass on the side of the road and stuffing them like memories in zipper bags
* Barbree: We're in the countdown, and I'm # I felt that little blow on my shoulder. I turned around and looked up and it was Jimmy Stewart and his wife, Gloria. And he said, "Are you okay if we look here?" And I said, "Mr. Stewart, you look where you want."
* Morgan: It was a wonderful countdown – I felt very relaxed. Except when you get to the very end, the last 30 seconds, just knowing the power of the boosters on board and that these three men are sitting up there.
* Lucas: The Saturn V stack weighed a little over 6 million pounds, so we had about 7.5 million pounds of takeoff thrust. When you see it take off, it seems that the tower will never go away. But as it burns fuel, it gets faster – the weight at the elevator decreases, so it picks up speed.
* Morgan: It's a pretty physical experience, an Apollo launch, because it's a slow take-off – and then the shock waves hit you. We could feel that happening in the shooting room because we had these shutters and they were beating back and forth, and the consoles were vibrating.
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* Sieck: When you're in the control room for the countdown, you focus on the technical data. [Standing outside] was like the difference between watching a sporting event on television and being in the crowd at the stadium. People were jumping up and down, screaming and screaming, honking. It was great.
* Lucas: The first stage burned for about 2 to 3 minutes, then it was spent, and the second stage and everything above was flying. The second stage had five J-2 engines, each of which had about 150,000 pounds of thrust. At the exhaustion of this stage, the third stage, the S-IVB stage, was lit. He had a J-2 engine of about 200,000 pounds of thrust
* Jay Finst, Saturn V IBM Flight Computer : I see it as a runway relay. You have a runner, and he runs and passes the baton to the next runner, and this runner runs and gives the relay to the next runner. And the race is not over as long as the witness is not transferred to the last man and that he crosses the finish line. This launch is the same path. The first step, the S-IC, must work and the relay goes to the next step. Step S-II must work and pass the relay at step S-IVB – this must work. And you go back to the S-IVB stage again, and it must work. You passed the baton four times to have a successful mission
* Lucas: The second and third stages were fueled by hydrogen, and it was the first time that the Hydrogen was used. used successfully in a rocket scene. You might wonder why we did not use this for the first step – that's because it's so light that it would take too much volume in the tank. Kerosene fuel was more effective for the first phase while you were still in the Earth 's atmosphere.
* Finst: The shooting room had people of all [the manufacturers]. I'm sure the Boeing have held their breath as the first step, S-IC, would do its job. Then they had stage S-II, the next step, and I'm sure the North Americans held their breath to fire and do their job. And you had the S-IVB stadium and he pulled his engines. And again, you had someone, Douglas S-IVB, holding their breath.
* Barbree: What [the crew] did first is go into low Earth orbit, circling like an orbit and half while they were checking everything. Everything was fine for TLI [Translunar Injection]
* Barbree: The S-IVB step again fired, which increased the speed of Apollo 11 by 17,300 km / h in Earth orbit at over 24,000 mph – what they call the escape speed.
* Finst: No one left the shooting range, even if your boosters were finished, to see if the S-IVB would have his second start. The peculiarity of this engine is that it works once and you have shut down for two hours or three hours and you have to restart it. And the second departure, which is what everyone expects, is the long burn that takes the spaceship to the moon.
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* H. David Reed, Flight Dynamics Officer (FIDO), Green Team, Mission Control: Once the fire is out and everything is stable, the crew jumps from the front and turns around to get the lunar module. Then they turn again and start putting distance between them and the booster. Once you have captured the lunar module, from that moment you have a lifeboat.
* Alan Kehlet, Project Engineer Apollo, North America Rockwell: The mission recoiled from the adapter and returned the vehicle to capture the LM [lunar module]. We talked about using springs to roll back, but the thrusters on the service module were the simplest way
* Barbree: As soon as they had the l & # 39; translocal injection, we all ran like frightened rabbits to the airport, where we had a chartered motor plane for the media. We flew directly to Houston
16-19 JULY 1969, 1969: MOON-COASTING
* Charlie Dumis, Electrical, Environmental and Communications Officer (EECOM), Green Team, Mission Control : As soon as he got up, he became ours.
* Jack Garman, Group Leader, Program Support Group, Apollo Guidance Software Section: At the Mission Control Center, they had a congressional disposition – the flight director was the president; There were several positions in the main control room that dealt with different functions, and each of them had staff in adjacent rooms.
* Sy Liebergot, Head of Electricity, Environment and Communications, EECOM Team, Mission Control: I had four guys who worked for me in the back shop and who were much more expert in the systems that I was responsible for, and they had a greater ability to chart things in more detail.
* Joe Gavin, Director, Lunar Module Program, Grumman Aerospace Corporation: And on the other side of the hall, there was a group of half a dozen from engineers, some from Grumman, North America. first line backup of the mission control team
* Charlie Duke, astronaut, capsule communicator (CapCom), white team, mission control: Communications between the Mission control team and the crew was always done via CapCom, wh o was an astronaut. The thought was that a crewmember in the mission control would have a better understanding of what the crew was experiencing.
* Gene Kranz, Flight Director (FLIGHT), White Team, Mission Control: We always operated with four teams during lunar missions. We did this to balance the training workload, and because the changes are quite long, it gives them a break.
* Steve Bales, Guiding Officer (GUIDO), White Team, Mission Control: We were all 25 to 28 years old, except Gene, who was 35 years old. People who were attracted to NASA at that time were younger; It was not as if someone had already done this job. The crew, they were all 38, 39, 40 – they seemed a lot older for us. Or at least for me, anyway.
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* Neil Armstrong, Commander, Apollo 11: J & # 39; I was 24 when I joined NACA – later NASA – and I had a very challenging job both as a pilot and as an engineer in flight research. I was confident that men of this age could do the job. In addition, this new space age required people who understood digital computers, and most people in this category were in their twenties.
* Garman: Nobody knew much about computers at that time – and no one knew much about flying spaceships either. If people thought, "Is a group of young kids going to screw up this mission?"
* Chris Kraft, Director of Air Operations, Mission Control: On the way to the moon, you could say, "Well, that could be a pretty boring time. "But that's not true.There were times when you had to do things with fuel cells, when you had to get rid of water in the system.You make sure that the thermal operation of the spacecraft is well done.On Apollo it was called the barbecue mode.
* Hugh Blair-Smith, software engineer for the computer guiding Apollo, MIT Instrumentation Laboratory: During the three long days from Earth to the moon they had to keep the spaceship rotating like a pig on the spit, so that the sun was not concentrated. no side
* H. David Reed, Flight Dynamics Officer (FIDO), Green Team, Mission Control: There is a lot of degassing of the service module – ventilation by This will change the course, if you go 238,000 miles and walk sideways [of the craft] and that you even blow it, this slight movement will be multiplied by a lever length of 238 000 miles
* Hal Loden, lunar module control officer (CONTROL), Black Team, Mission Control : You do not want to hit the moon, but when you miss it, you want to miss the right altitude and tilt so that you will go into orbit.
* Reed: So we will follow him for a moment, notice that the trajectory changes and make a correction midway.
* John Llewellyn, Retrofit Agent (RETRO), Green Team, Mission Control: In those days, we had no GPS and all that. The crew did not have any either. They had almost the same thing as Columbus – a sextant and a field of stars
* Buzz Aldrin, Lunar Module Pilot, Apollo 11: Because of the l? importance of the mission, we do not have I do not want to have distractions in case we have other distractions that really require our attention. We asked them to do extrinsic experiments on the outside, so we could focus on mid-course corrections, platform alignments, relationships, sleep and meals – the things we do We really had to do
NASA Public Affairs Officer: In Mercure and Gemini, nothing was broadcast live – not even airborne. But once at 10 or 20 miles from Earth [on Apollo 8] they were in permanent contact. From that moment, all communication was live
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Mechanics of the People
* Armstrong: Throughout Science Fiction – Jules Verne, HG Wells and others – no writer had ever envisioned that lunar explorers would be in communication with people on Earth or, more surprisingly, would be able to transmit still images or moving images to the Earth. So we understood that it was an important part of our flight objectives.
* Llewellyn: When you cast from the Earth, when you see the moon for the first time, it looks small. A few days later, every time you look at the moon, it gets bigger and bigger.
* Aldrin: [We were] just watching the Earth slowly faint. The stars did not change – sometimes they were visible because the ambient light was quite low.
* Llewellyn: And finally it gets so big that we do not see anything else.
* [19659011] Aldrin: Suddenly, someone noticed through the window that the moon was covering the sun. It was a big black object, much bigger than the sun, and the sun illuminated it. Wherever the Earth was, it did not shine enough to cause shine, as the glow on the edges [of the moon] was so prominent and extinguished in all directions. No eclipse photo or any film that I have seen has shown such a crown.
* Llewellyn: Navigation depends on three things: you need to know where you are and you need to know where you are going … -and you must know it. Then it's easy because all you do is modulate your velocity factor until you get there. The biggest problems are the end points. We used to put a line on the window, and if that line was below or above the horizon [when the module got to the moon] they would immediately do a maneuver. Because no matter what we know if it's not there when we see it.
* Chuck Deiterich, Retrofire Officer (RETRO), Black Team, Mission Control: When you go out to the moon, we always try to have several maneuvers in the hands of the crew, so if they lose communication, they can return to Earth. Five hours before passing behind the moon, we had a maneuver where you could fly around the moon. If, for one reason or another, you did not go into lunar orbit, we had a maneuver that would allow you to return to a good water landing [Earth for a]. If you had a problem during the insertion of the lunar orbit – it's a big burn – we had prepared a chart that said if you turn off the engine at that time, that's What are you doing to recover
When Apollo 11 passed behind the moon, and out of touch with Mission Control, a 6-minute burn placed the craft on an elliptical orbit. Two orbits later, a second lunar orbit insertion, also behind the moon, lasted 17 seconds and dropped the vehicle into a circular orbit
* Reed: They were pulling the engines behind the moon so you would not see it. But we would transfer the delta speeds – give them everything they needed for the guidance system. We also gave them to him on a piece of paper, which was a backup copy. So by entering the lunar orbit insertion, they had the information they needed to get in, but the computer did it. Then, of course, the spaceship turns around, pulls back and brakes in a 60-mile orbit.
* Bruce McCandless, Astronaut (CapCom), Green Team, Mission Control: After Apollo 11 fell into orbit around the moon, Frank Borman received a message from the Soviet Union said: "Congratulations on reaching the lunar orbit, we also have Luna 16 orbiting the moon and its orbital parameters. presents any problem, please advise and we will move it. "We did not need Luna to be moved, but I thought it was a noble gesture at this time of the Cold War."
On July 19, 1969, a pair of burns were made. lunar orbital insertion brought Apollo 11 into orbit around the moon.Three-day coast of the Earth.In the 11th revolution, the white team assumed consoles in mission control in preparation for the descent. [19659148] JULY 20, 1969 – LANDING DAY
* Gene Kranz, Flight Director (FLIGHT), White Team, Mission Control: I remember very clearly when I left home. Had my haircut fresh, and my wife had packed a lunch bag that was enough for three teams.On arriving at my parking spot at [the Manned Space Flight Center] I realized that I did not I did not remember going through Clear Lake, or anything else … I was so concerned that I was flying automatic * Steve Bales, Orienteering Officer (GUIDO), White Team, Mission Control: When we arrived this morning, the lunar module was dead. We had to turn it on, align everything and check. In the simulations, it is there that we had always had the greatest difficulty, really. We had never finished without a major problem – and I do not know if we managed to train successfully – what we called a power up and initialization of everything, and then we made a landing. * Sy Liebergot, Head of Electricity, Environment and Communications (EECOM), Black Team, Mission Control: We had both the # 39, descent team and the control center lift team. If we had to abort and descend from the lunar surface, the guys on the descent would leave the console and we would get into position to complete the part of the mission for which we had been specially trained. * Chuck Deiterich, Retrofire Officer (RETRO), Black Team, Mission Control: Coming from an abortion, there are many places where you could start which made the task more complicated. But the abortion target is trying to get you to a point that simplifies the appointment. * Llewellyn: I had used to go to the control center at night and open the computer; I would work with Collins in the simulation building. He simulated abortions and I told him what kind of orbit he was taking and how it was coming out. That really kept me on the edge. * Kranz: I had a conversation with the controllers before the moment we entered the landing phase of the mission. I indicated that whatever decisions they would make that day, I would be behind them – that we walked into the room as a team and that we would leave as a team. * Jack Garman, Group Leader, Program Support Group, Apollo Orientation Software Section: It Became Really Real While [the spacecraft] circled the moon and was preparing to break up. In fact, I remember very well the Lock Control Center. The guards were not to let anybody or anyone in. Advertisement – Continue reading lower Buzz Aldrin, lunar module pilot, Apollo 11: At this point, we maneuver to retreat, engine first and face down, in the attitude where we will start the motorized descent. * Joe Gavin, lunar module director, Grumman Aerospace Corporation: It was tense because we were basically designers of aircraft. In the aircraft industry, you have always tested something before delivering it. In the case of the lunar module, you could not test it in flight. Each launch was a brand new vehicle. * Doug Ward, NASA Public Affairs Officer : All along the way, we continued to lose communications and this would come back and we would lose it again. I was on the edge of my seat thinking, "You know, we're going to abort for that." * Kranz: I had a Mission Rule that I'd was the only interpreter. It was: Do we have enough information to continue, both voice and telemetry. * Glynn Lunney, Flight Director (FLIGHT), Black Team, Mission Control: The mission rules were a bit like what we would need to stop. to land on the moon. They became like a set of commandments, or a set of ethics to help understand how much risk we were willing to take, and for how much reward. * Kranz: The first thing [my team]] did was use Mike Collins as a relay – we had done this at training a few times. * Ward: In fact, communications officials were not too worried because they understood why it was [cutting out]. The lunar module was in a position where it was blocking high gain antennas. They knew that while maneuvering they were descending to the lunar surface that corrected itself * Aldrin: He was finally stuck and was in good shape, as he was supposed to be # To be . ] Don Eyles, Software Engineer, Lunar Module Calculator, MIT Instrumentation Laboratory: The landing maneuver began with the spacecraft at its lowest point in a lunar orbit. About 9 miles. * Bob Carlton, Lunar Module Control Officer (CONTROL), White Team, Mission Control: When we first launched it, the flight director was the round of the room. He wanted to hear your voice. When Gene arrived at [Steve Bales] he just exploded "GO!" And I heard Gene a little sneer, and we all did it, but it sort of relieved the tension. I thought, "Now you do not do that." So when I gave my departure, Gene said, "Control," and I said, "I'm leaving, Vol." Later, he commented that I was calm and calm, but he did not know that I was doing an act. * Kranz: We gave them the green light for the start of the motorized descent. doggone, juste au moment où les moteurs ont commencé, nous avons perdu des données à nouveau. Nous l'avons ramassé momentanément par la suite, et très peu de temps après, un agent d'orientation a indiqué que nous avions des perturbations de trajectoire. En fait, il a dit: "Nous sommes à mi-chemin de notre limite d'abandon." Eh bien, c'est un peu sportif avant même de remonter à la surface. Publicité – Continuez à lire ci-dessous * Aldrin: Nous sommes environ une minute, peut-être 2 minutes, en descente motorisée, Faceown, et Neil me dit, et la Terre, "Je pense que nous allons être un peu long." Je me suis dit, comment dans le monde peut-il vraiment, à ce stade, dire que nous allons être un peu long? * Neil Armstrong, commandant, Apollo 11: Avant d'allumer le moteur de descente du module lunaire pour initier la trajectoire vers la surface lunaire, j'avais été chronométré notre taux angulaire sur les cratères sur la surface ci-dessous pour calculer notre altitude. J'ai noté qu'au moment de l'allumage, nous étions quelque peu à l'ouest de notre point de départ prévu. J'en ai déduit que toute notre trajectoire et notre point d'atterrissage seraient quelque peu à l'ouest de notre point d'atterrissage prévu. * Aldrin: J'ai appris que chaque fois que Neil dit quelque chose, tu ferais mieux de faire attention parce que ça a du sens. * Bales: Le module lunaire Il pouvait faire beaucoup de choses de façon indépendante, mais il devait compter sur les gens au sol pour dire à l'ordinateur où il commençait sa position d'atterrissage. Sur le dos de la lune, il y avait eu une ventilation – des perturbations inconnues de nous. Le temps que nous leur avons donné pour allumer le moteur était d'environ 4 ou 5 secondes en retard. * Aldrin: Il y a un moment dans la liste de contrôle où nous faisons un mouvement de recul pour que nous soyons face à face, puis un peu en avant avant de ralentir. Le but est de faire en sorte que le radar d'atterrissage se verrouille sur la surface à environ 30 000 pieds. * Bales: Alors que le véhicule lunaire tangue, le radar d'atterrissage doit changer de position. Nous avions toujours dit que si ce changement ne se produisait pas à 10 000 pieds, nous allions abandonner. La veille de notre atterrissage, j'étais à une réunion avec 30 ou 40 personnes qui ont construit le radar, qui a construit l'ordinateur, qui connaissait les trajectoires d'atterrissage, qui se disputaient sur ce que nous allions faire si le radar se bloque en position primaire * Kranz: Nous avions donné au vaisseau spatial la meilleure connaissance de son altitude au-dessus de la surface lunaire avant la descente motorisée, mais nous avons dû la mettre à jour en fonction des données réelles du radar. 19659045] "À l'époque, je pensais que notre pire problème était terminé, notre pire problème était sur le point de commencer." 
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* Balles: Dès qu'il était verrouillé Sur, le radar a vu que nous allions un peu vite en vitesse radiale et corrigé l'ordinateur. À l'époque, je pensais que notre pire problème était terminé. Il s'est avéré que notre pire problème était sur le point de commencer.
* Aldrin: Nous avons eu la première alarme 1202. Nous nous regardons les uns les autres, et nous savons que c'est dans le dictionnaire de guidage et de navigation, mais plutôt que d'essayer de le sortir pendant que le module effectue une descente motorisée, Neil leur a demandé quelle était la lecture de l'alarme 1202. Puis nous avons eu un 1201.
* Charlie Duke, astronaute, communicateur de capsules (CAPCOM), White Team, Mission Control: J'ai été choqué. En fait, "étourdi" est un meilleur mot. J'ai commencé à chercher ma liste de contrôle de guidage et de navigation pour voir ce qu'était un 1201 et un 1202. Et, bien sûr, Steve Bales a su immédiatement et n'a pas hésité longtemps à dire, "Nous sommes allés sur ces alarmes, Flight."
* Bales: Je l'ai à peine entendu. Si vous écoutez les [voice] boucles, il se passe beaucoup de choses. Et enfin, les données arrivent et nous voyons le 1201, et Jack [Garman] crie – je veux dire, crie presque littéralement, "C'est bon, c'est bon, tant que ça ne continue pas!"
Garman: Il y avait une équipe de contrôleurs de vol dont le rôle était de trouver des profils de simulation qui entraînaient ensemble les contrôleurs de vol et les astronautes pour survivre et réparer les choses. À un moment donné, ils m'avaient demandé de trouver un échec complètement lié au logiciel. Je l'ai fait quelques mois plus tôt, et ils l'ont conservé pendant l'une des simulations
* Liebergot: Il y avait généralement une relation plutôt antagoniste entre les pilotes de simulation et les contrôleurs de vol américains. pour voir s'ils pourraient nous outfox. Mais ils étaient assez importants. Ils nous ont entraînés à répondre à la plupart des problèmes que nous verrions jamais.
* Kranz: Dick Koos, notre superviseur de simulation, nous a donné les alarmes 1201 et 1202. Steve [Bales] had never seen this before. During the simulation, they had an abort, which was his call.
* Bales: There's a general rule in flight control: If you don't know what to do, don't do anything. The problem is, in the middle of a lunar landing, not doing anything is not an option.
* Garman: Gene Kranz sat us all down and said, "I want you to figure out every possible alarm code that can happen in flight so that we're prepared." In those days, there was no such thing as desktop computers. So I wrote down all the alarm codes on a sheet of grid paper, with crib notes on what they meant and what our response should be. And I stuck it under the plexiglass of the console I was to sit at. And, lo and behold, one of them–well, a couple of them–popped up during the actual landing.
* Eyles: What led to [the alarms] was an obscure mismatch deep in the electronics–two signals that should have been locked together in phase were only locked together in frequency. That hardware glitch involved the rendezvous radar, which really wasn't needed during the descent to the moon.
* Aldrin: I left it on. That turned out to be the main cause, and maybe the cause, of the program alarms.
* Eyles: Based on a random-phase relationship between those two signals, the rendezvous radar electronics were sending pulses to the computer at a very high rate.
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* Ward: The computer was simply saying, "Hey, I've got more than I can handle, but I'm gonna do the important things, so don't worry about it."
* Eyles: Under the software control, it did a software restart. Five times during the landing, the whole software was flushed and reconstructed in terms of what was being executed. And that load shedding was what allowed us to complete the landing without any appreciable glitches in the way the guidance system worked. Without quite knowing it, we had built a fault-tolerant computer.
* Garman: 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 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.
* Armstrong: The powered descent was the most challenging segment of the flight. The systems were heavily loaded, the margins were slim, and this would be the first time that the entire descent strategy would be fully tested. A decade earlier, while I was flying in the X-15 program, we learned, surprisingly, that all the pilots, while flying the X-15, had heart rates between 145 and 185. It reflected the mental intensity appropriate for a challenging situation. The Apollo data seemed to correlate well with our prior experience.
* Duke: I didn't notice anything panicky, any tension at all in them. We just kept feeding them the information, trying to be as professional about it as possible. I don't think I was relaying any anxiousness in my voice–I tried not to, anyway–but tension was building.
* Aldrin: As long as you've got communication, Houston knows what [the problem] is, and they have more information, so they're going to be the ones that call the shots.
* Liebergot: We weren't exhaling, but very businesslike. And that's not to say the job was just ho-hum; it was not. It's that we, with hearts racing, did our job.
* Eyles: The first two [landing] phases were very much under the computer's control using different targets. The final landing phase was the point where the astronauts took over semimanually to maneuver the spacecraft like a helicopter. When I say semimanually, I mean that the automatic system was controlling the throttle to maintain a commanded descent rate while the astronaut commanded the attitude of the spacecraft in order to scoot along the surface in whatever direction he needed to go.
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* Bruce McCandless, astronaut (CAPCOM), Green Team, Mission Control: Neil was flying, looking for a boulder-free spot. It's fair to say people were holding their breath. But Neil had a considerable amount of experience in the lunar module simulator and in the lunar-landing research training vehicle.
* Armstrong: Every flying machine has its own unique characteristics, some good, some not so good. Pilots naturally fly the craft in such a manner as to take advantage of its good characteristics and avoid the areas where it is not so good. In the case of the lunar module, surprisingly, it flew much more smoothly than I had expected based on all the simulator work we had done. It was a welcome surprise.
* Gavin: The lunar module had the first really throttle-able descent engine. When it first fired, it had to operate at about 10,000 pounds of thrust. But as they approached the lunar surface, the vehicle became much lighter, having burned up a lot of fuel, and they had to get the thrust down to maybe 2000 pounds. So it was quite a development to get a rocket engine that would not only do this, but would operate smoothly in either range.
* Bales: There wasn't a lot being said, but we had a lot of data. I was thinking, "What in the bloody heck is going on?" Normally, in the simulations, once [Armstrong] got on a path to come down, he killed all the velocities but altitude rate and pretty much just came straight down. But he wasn't. He had a forward velocity of 20 feet per second. And, of course, that was eating up fuel.
* Gavin: In an airplane you usually have, oh, at least an hour's extra fuel in case the airport is closed where you're going. But in the case of the lunar module, we had about 120 seconds of margin.
* Kranz: We got what we call "low level" in the propellant tank. Once we got that indication, we knew we'd have roughly 120 seconds of propellant remaining at a hover throttle setting.
* Carlton: We had never seen that light, never expected to see it. In all of the sims, we had so much margin, that wasn't normally a factor.
* Garman: At that point there was nothing the ground could do except watch. It became a spectator activity. The tension went up noticeably. Very noticeably.
* Duke: When we got down to the last minute or so, it was real quiet. Everybody was glued to his monitor.
* Carlton: I had a stopwatch. I'm looking at it, and at the same time I'm looking at the altitude, and I can see it's still a long way down. I didn't know it, but the guys were flying over a crater. We call up 30 seconds. I'm thinking there's no way we're going to make it.
* Kranz: I'm a Catholic, and in the flight director business, you want all the help you can get.
* Carlton: When the engine shut down, I had 18 seconds to the point where we would have aborted.
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* McCandless: I was in the control center as a spectator, sitting right next to Charlie Duke, who was the CAPCOM. Once Neil came back with his transmission, "Tranquility Base here. The Eagle has landed," in spite of the earlier admonitions to maintain decorum, we burst into spontaneous cheers and applause.
* Duke: That's the first time he'd used that. The call sign was Eagle, so we'd just been using, "Eagle, this is Houston," "Houston, Eagle." As you can hear in the transcript, I was so excited, "tranquility" came out, "twank." I caught myself before I finished the word, "Twank–I mean, Tranquility. Roger, Tranquility, we copy you down."
* Ward: Kranz immediately got on the loop and said, "Everybody settle down. Settle down. We've got some critical calls to make, and we've got to focus on what's coming up here."
* Kranz: We had a job to do, because in the next 2 minutes, we had to make the first of our stay/no-stay decisions.
* Ward: But in the meantime we could hear this roar from the viewing room behind us. All of the politicians and top managers and astronaut families and so on were back there behind the glass.
* Aldrin: It was certainly momentous, but there were no trumpets blowing or cymbals crashing. We're there, we're two guys, and we're not the yippee type. We see something, absorb it, think about it and that's it, accept the way it is.
EXPLORING THE MOON
After an eventful descent to the lunar surface, Mission Control checked the spacecraft's systems and confirmed it was safe to stay on the moon. Here, the Green Team assumes the consoles so that an adrenaline-filled Aldrin and Armstrong can get a head start exploring the lunar surface. They pack in several experiments and a Presidential phone call before eventually lifting off to rendezvous with Collins, orbiting overhead in the command/service module.
* Bruce McCandless, astronaut (CAPCOM), Green Team, 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 8 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.
* Buzz Aldrin, lunar module pilot, Apollo 11:We wanted that to be the way the flight plan read, so that if we made a change, it was a change in the positive direction, not in the negative direction.
* Milt Windler, flight director (FLIGHT), Black Team, Mission Control: It was a pretty easy decision. You probably can't stop them, so why not go ahead and do it? Plus, we were all ready to get on the moon, too.
* McCandless: Driving back out to the center along NASA Road 1, it just so happened I was aimed right at the moon, which was nearly full. I had this eerie feeling that the moon didn't look any different to me from where I was here on Earth, and yet intellectually I knew the lunar module and Armstrong and Aldrin were on it and I'd be talking to them. It was one of those "This does not compute" type things. It wasn't until I got inside the control center and was talking to them that everything seemed to come back into the realm of reality.
* Don Beattie, program manager, Apollo Lunar Surface Experiments: One scientist had projected that when the lunar module landed it would disappear into levitated dust. Even though we landed the Surveyor spacecraft successfully, that was a real concern.
* Joe Gavin, director, Lunar Module Program, Grumman Aerospace Corporation: When we started all this, we didn't know what the surface of the moon was like. We went ahead with a very conservative landing gear design because there never had been a rocket-propelled vertical-landing machine.
* McCandless: It was a relief that the dust on the lunar surface was actually only half an inch deep.
* Beattie: Another [concern] was that the dust would be pyrophoric–that when they opened the cabin of the lunar module, oxygen would react with dust and explode. There was no way we could be sure until the guys opened up the door and the oxygen flowed out.
* McCandless: They depressurized the lunar module, opened the hatch and Neil came down the ladder. There was a crude black-and-white TV camera, which transmitted images along the lines of a white blob going down some sort of inclined structure. I remarked, "Okay, Neil, we see you now, we've got you on TV."
* Ward: I was very conscious of the fact that what the crew said was extremely important historically. The commentator stepped on a foot switch that interrupted the air to ground, so anytime we talked it obliterated whatever the crew was saying.
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* Jay Barbree, correspondent, NBC News: He gets to the bottom of the stairs, takes a step on the moon to make sure he can, steps back up and says, "That's one small step for [a] man, one giant leap for mankind." *
* 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." But he came back with his now famous [line]. The media immediately wanted to know if it was one small step for a man, or just man. There was a little bit of static, so it wasn't entirely clear.
* McCandless: The first order of business was collecting a contingency sample. Neil was supposed to scoop up whatever was near his feet, the first thing that was handy, so that in the event of an emergency they would have at least something to show for having been there.
* Beattie: The bulk sample had a different purpose–to make sure that we got a very wide variety of material.
* Harrison H. Schmitt, astronaut, mission scientist for Apollo 11: The Apollo astronauts were very well trained engineers to begin with, and they were test pilots as well, which meant that they had very, very good observational skills. So we tried to give them a fundamental understanding of what they were going to encounter and the types of samples that we hoped that they would be able to collect.
* McCandless: Then Buzz came down and the two of them set up EASEP, the Early Apollo Scientific Experiment Package–a stand-in for ALSAP [the Apollo Lunar Surface Experiment Package].
* Schmitt: The Apollo Lunar Surface Experiment Package contained a number of individual scientific experiment packages by principal investigators from around the country. As soon as we started to really concentrate on what might be required to deploy that instrument package, it became very clear that there wasn't enough time. Simultaneously, it was becoming clear they were gonna need every weight margin that they could get in order to add to the amount of time that the crew would have to find a good landing spot–hover time. So we developed as quickly as possible a much simpler, smaller package for that first mission that would contain the two experiments that seemed to be the kind of thing you would want to have put on the moon just in case you never got a chance to go back.
* Beattie: The most important was the seismometer. That was going to tell us whether there were moon quakes, and possibly also something about the internal structure of the moon. Then we had the lunar retro reflector, which was deployed in order for us to take accurate measurements of the Earth-moon distance.
* Chuck Berry, chief flight surgeon, NASA: We were concerned about the metabolic cost of working in the bulky suit. The best way to monitor them on the lunar surface turned out to be the change in water temperature in the water-cooled undergarments. We had sensors to measure that, and we could then sort of gauge how far they could go.
* Neil Armstrong, commander, Apollo 11: On the lunar surface we had both the 16-mm movie camera and the television camera in fixed positions so our surface activities would not be slowed by camera position and setting requirements.
* McCandless: The mission was about 2 hours and 20 minutes in duration. About 15 minutes into it, the flight director gave an advisory that President Nixon wished to speak with the Apollo crew. After a little consultation, we decided it was President Nixon's prerogative to talk to the crew, but we had a lot of work to do before we felt we could afford the time and the minor disruption to the schedule. So we basically put him off for a little over an hour. We got the impression he was getting increasingly unhappy. But slightly after the midway point, we did get him on. I got Neil and Buzz to stand near the flag, within view of the TV camera, and [Nixon] talked for a couple minutes.
* Schmitt: Once an extravehicular activity starts the crew is going to move along the timeline and get as much done as they possibly can. Buzz Aldrin was talking about a lot of things that he was checking, like mobility.
* Aldrin: After the flag was up, I made a point of being in front of the camera just demonstrating different means of moving around.
* Schmitt: While he was doing that we were all wondering what Neil was doing. Well, Neil was…collecting this very fine and diverse group of rocks and soil. Not only did he get a very wide distribution, but he also thought the box looked a little empty, so at the last minute he filled it with just the dirt, so to speak–what we call the lunar regolith. That sample turned out to be the best, most comprehensive sample of the lunar regolith that was ever taken on any of the Apollo missions.
* Armstrong's famous words have been the subject of much speculation. Lunar surface communications were voice-activated and subject to interference, so a vowel could easily have been dropped. Armstrong confirmed to Popular Mechanics that he did articulate the "a."
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BLASTING OFF THE MOON'S SURFACE
*H. David Reed: I took my headset off, which is what you do if you don't want anybody to hear what you are about to say, and told Gene [Kranz]"We have a problem: We do not know where the hell they are." There was only one way to figure that out. The capcom woke Buzz Aldrin one rev early to do a rendezvous radar check. Because I knew where the command module was and I had the vectors that allowed me to translate back down to the surface, I could find out where the lunar module was. They were off another 5 miles from anything that we had.
* Joe Gavin, director, lunar module program, Grumman Aerospace Corporation: In my mind, the riskiest unknown in the whole mission was the takeoff. When the astronaut pressed the button, a whole bunch of things had to happen. The explosive bolts connecting the two stages had to fire. And then the ascent engine had to be ignited to lift the ascent stage off. And somehow as it left the descent stage, the exhaust from the ascent engine had to go somewhere.
* Chuck Deiterichretrofire officer (RETRO), Black Team, Mission Control: We also kept track of the rocks in the LM and where they were stored. We had a computer model that had all the cabinets and cubbyholes and things. The ascent stage of the engine did not gimbal–they used little RCS jets to keep it stable–so if the center of gravity got too far off it would not fly. You had to have all those rocks pretty much where you wanted them.
* Owen Garriott, astronaut (CAPCOM), Maroon Team, Mission Control: The engine on the lunar module has one chance, which must be perfect. People had spent a lot of time back at Grumman doing the design, preparation and testing for it.
* Buzz Aldrin,lunar module pilot, Apollo 11: As I got down on the floor to sleep [the night before]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 (CONTROL), Black Team, 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.
* Glynn Lunney, flight director (FLIGHT), Black Team, Mission Control: Once the ascent stage is lit, the vehicle really jumps off the moon.
* Aldrin: It was not a gradual liftoff. It was a sudden departure–but without any of the forces that go along with rapid acceleration. Looking out the window, everything was getting smaller so fast that [we didn’t really notice] the craft going through a gradual pitch forward.
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*Chris Kraft, director of flight operations, Mission Control: When we first started thinking about going to the moon, we really didn't think about doing rendezvous at the moon, and, frankly, having two vehicles. The first thoughts were that we would have what we called "direct descent"–that is, go directly from the Earth to the moon. And an Earth-rendezvous mission where you put the vehicles in Earth orbit, rendezvoused with the lunar module and the command module, and then sent both modules to the moon.
* Gavin: The original von Braun approach was everything that got out to the moon would go down to the surface and then back up. It was absolutely vital to the success of the whole enterprise to have a separate vehicle to do that, because it saved the energy that would have been involved in taking a lot of extra weight to the surface of the moon and then back up again.
* Kraft: What drove that, more than anything else, was the performance of the rockets and the complexity of the systems involved on one or two spacecraft. You could separate that by having two modules. And the real kicker, in my opinion, was that when you tried to do it with only one module, the vehicle ended up being so tall, so long, that the pilots were a long ways away from the surface that you were trying to land on.
* Hugh Blair-Smith, software engineer for the Apollo guidance computer, MIT Instrumentation Laboratory: 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. But they did it because everything else had much bigger problems.
* Gavin: It was an emotional worry that people had. But those of us who were directly involved with the details were always very confident–otherwise we wouldn't have said we were ready to go.
In order to dock with the command/service module, the lunar module executed a series of burns—including two behind the moon—in a complex sequence lasting nearly 4 hours.
* Gavin: When the vehicle was behind the moon, there is no communication. The control team always had a timeline that said communication should resume at this hour, this minute, this second.
* Loden: You like to be able to be looking over their shoulder, so to speak, with the telemetry, but you've got to do these maneuvers at certain points in the orbit if you want to perform the mission.
* McCandless: There's not much you can do other than stand there and look at these old black-and-white TV screens with cameras trained on systems for generating numerical data. When we acquired a lock on their radio signal there was one indicator that went from a down arrow to an up arrow. There would be a sort of palpable feeling of relief.
* Deiterich: When they came whipping around the moon, [the crew] had already closed out the LM. The systems engineers were concerned about flying for two more hours with the coolant loops turned off. We were in a particular attitude that was really not good for jettisoning the LM–that attitude was set up for 2 hours later. When we popped [the lunar module] off, it was drifting up and away. The problem with that is, one rev later, it's going to come right back to the same spot that you're in–so you have to do an evasive maneuver. About 20 minutes later we did a CM retrograde burn; in other words, we actually slowed the orbit down by 2 feet per second. What that does is put you out in front of the LM, so when you do TEI [trans-Earth injection] you continue to move away from it.
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* McCandless: Lunar orbit insertion was critical to a mission's success, but it was less critical to the survival of the crew than the trans-Earth injection burn. If you couldn't get out of lunar orbit you had a real problem.
*Alan Kehlet, Apollo chief project engineer, North American Rockwell: Some guy ran an analysis of all the critical events that had to take place and came to the conclusion we didn't have enough reliability, that it would never work. But we discarded it.
* McCandless: It pretty well boiled down to the SPS–service propulsion system–engine; that had redundant valves, circuits, actuators, switches. Everything was singlefold redundant. If it didn't fire automatically it was possible to fire it manually but nobody really wanted to do that.
* Kehlet: [Apollo 11’s command module] had the best-performing engine and equipment. We didn't have a lot to spare, mainly because of cost, so the idea was that you robbed the next vehicle to go to the Cape for equipment you needed. I made sure that 107, the spacecraft on mission Apollo 11, got separated from all that. I worked longer hours than [everybody else].
* Deiterich: We were in good shape to do TEI. But when you're doing a 2800 feet per second burn you can't do it perfectly. It only takes a couple feet per second to change what your entry conditions will be. So we have a midcourse correction about 15 hours after TEI and another one about 24 hours before re-entry.
* Loden: Of course, the lunar module stayed in orbit around the moon and we watched it die. It was like losing a good friend. But it performed its job tremendously well, and we configured certain systems in ways that, after jettison, would give us insight as to how long it could last.
* Bob Carlton, lunar module control officer (CONTROL), White Team, Mission Control: The name of the game for us flight controllers was to try to learn the outer limits of all of our equipment. Some people called it playing with it, but it was serious business. We wrung that thing out.
* Loden: It was tougher than we thought.
* Gavin: And then the rest of the mission was a matter of waiting until orbital mechanics brought everybody back to Earth.
ENTRY AND SPLASHDOWN
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* Chuck Deiterich, retrofire officer (RETRO), Black Team, Mission Control: About 16 hours before re-entry the recovery guys came up and said, "Hey, we've got bad weather where you're going." It was too late to change the time of flight, to let the Earth rotate underneath you, so what we did was fly an entry range. You could actually fly a different trajectory through the atmosphere and land [further] downrange.
* H. David Reed, flight dynamics officer (FIDO), Green Team, Mission Control: Coming back from the moon, you're coming in a lot hotter than ever before–at 36,000 feet per second. In Earth orbit, it's 25,000.
*Chris Kraft, director of flight operations, Mission Control: Because the velocity is so high, if you tried to come in directly, the heat-shield requirements would be too great. So what we did was get them into the atmosphere, skip it out to kill off some of the velocity, and then bring it back in again. That made the total heat pulse on the heat shield of the spacecraft considerably lower.
*Milt Windler, flight director (FLIGHT), Black Team, Mission Control: It was [still] so hot that the heat shield was abrading and there was a big ionization shield all around them. It prevents communication until [the command module] slows down enough for that to stop.
* Clancy Hatleberg, pararescue-man, underwater demolition team 11, U.S. Navy: The USS Hornet had steamed all night long with the helicopters, the two recovery teams and myself. The sea states were the highest we had ever encountered in any of the simulated exercises that we had performed in preparation.
* Buzz Aldrin, lunar module pilot, Apollo 11: There's a big solidness to the force as you're coming into the atmosphere, and it's gradually decelerating the spacecraft. You could sense a g before it really showed up on the indicator, and by then it's pretty firm. It's pushing you toward the back of the couch and down.
* Hatleberg: I was in helicopter 66. I remember looking out of the cockpit, and I could see we were on the outskirts of a storm: The sun was rising up above the clouds, but it was dark down below. It was sort of like being caught between night and day. Then all of a sudden I saw this streak coming through the upper atmosphere. It looked like a meteor. And then three chutes opened up.
* Bruce McCandless, astronaut (CAPCOM), Green Team, Mission Control: The whole mission was about as close to perfect as you can get with three human beings onboard and an unexplored terrain.
*George Mueller, associate administrator for manned spaceflight, NASA: Looking back, it was really a whole lot of people working on the same problem, making sure the piece that they had would do what it was supposed to do when it was supposed to do it–10 million pieces and 400,000 people. And every one of those people was very, very dedicated.
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* Liebergot: We were young, and we were fearless and, after all, nobody had ever told us young engineers that we couldn't successfully land humans on another planet. So we did it.
This appears in the June 2009 issue.