Apollo: The Race To The Moon

by Catherine Bly Cox

Massive as the Saturn V seemed to an onlooker, it would not naturally go in a straight line. On the contrary, lacking a guidance system it would have been as unpredictable as a child’s skittering balloon. The job of the guidance system was to ensure that the line of thrust of the launch vehicle was aligned with the center of mass. To that end, the guidance system checked the vehicle’s position, attitude, velocity, propellant levels, and a few dozen other variables every two seconds, and then sent messages to the four outboard F-ls (the center engine was fixed).

Only a few years earlier, they had been hesitantly trying, often failing, to launch rockets with a single, small engine in each stage. Today, in its first trial, they had launched a rocket the size and weight of a Navy destroyer, carrying eleven new engines, new fuels, new pumps, new technology of all kinds, and had done it perfectly. There was simply no way to explain it. They could recite how heavy it was and how powerful and how many parts it contained, but that didn’t capture it.

HERE MEN FROM THE PLANET EARTH FIRST SET FOOT UPON THE MOON JULY 1969, A.D. WE CAME IN PEACE FOR ALL MANKIND —Inscription on a plaque attached to the leg of the lunar module Eagle

The first of Kraft’s precepts was simplicity itself: “If you don’t know what to do, don’t do anything.”

True wisdom in flight control lay in being able to recognize one’s own ignorance. Much of the training of the flight controllers consisted of showing them how they could be fooled.

Beginning with Gemini IV on June 3, 1965, control of the flights shifted from the Cape to new facilities in Houston. Meters gave way to computer screens. Ad hoc conference calls gave way to a nationwide communications network. The modest goal of simply understanding what was happening to the spacecraft gave way to ambitions for solving hardware problems while the flight was still in progress. By the time the Apollo manned flights began, the Mercury Control Center that supported John Glenn’s Mercury flight had been supplanted by a system that was to Mercury Control as the Saturn V was to the Redstone.

The key was being smart enough to recognize the mistake, correct it, and then never repeat it. (“To err is human, but to do so more than once is contrary to Flight Operations Directorate policy,” was another of Kraft’s sayings.) And above all else, when you found out you had made a mistake you had to admit it immediately.

During Gemini, Kranz acquired the nickname “General Savage,” after the hard-driving hero of a contemporary television series (earlier a movie), Twelve O’Clock High.* When an anonymous controller made a stencil of the name and hung it outside his office door, Kranz left it there as long as he was in the office. He loved it.

By the fall of 1967, the apparatus for controlling manned space flight—the MOCR, its support network, the mission rules, the skills—had been evolving for eight years. Mercury had been elementary school, teaching the neophyte flight control team the rudiments, and occasionally showing by harrowing example how much remained to be learned. Gemini, consisting of ten manned flights with two-man crews during the period from March 1965 through November 1966, had given the controllers a chance to become proficient in advanced concepts such as rendezvous, extended flight, and extra-vehicular activity.

Tindall recognized that what matters most to people is not that they get their way, but that they feel they have had a chance to make their case. Somebody would voice an idea, and Tindall would field it, treating it seriously and yet at the same time managing to dispose of bad ideas quickly without putting anybody down.

“I could say it’s hard work, perseverance, all of those things. But it was the training process that did several things to you. First of all, it humbled you. And you’d have your successes too, and you felt good about them. You learned to pay exquisite attention to detail. You learned the nuances of the voices that are talking to you on these loops. By the time you’re finished, they have worked you over so much and so well and so thoroughly that you never considered failure.”

Within the world of Apollo, the outside world looked completely different. “I missed the entire Vietnam War,” said one, typical of many. “I watched no television, read no newspapers, came to work at six in the morning and worked until nightfall, six or seven days a week for years.”

The people of Apollo were barely aware that the Vietnam War was going on, barely aware that this was a Presidential election year, barely aware that there was such a thing as a War on Poverty or L.S.D. or Sgt. Pepper or race riots. Had one of Chris Kraft’s flight controllers been asked about the most important event so far of 1968, he would probably have said that it had occurred on January 22, when the unmanned Apollo 5 had carried a lunar module on its first test flight. Today, April 4, was going to be the next important date of 1968: the unmanned flight of Apollo 6, the second flight of a fully operational Saturn V.

Because the likelihood of a dual failure was so remote, the Marshall engineers had not spent much time analyzing how the Saturn V would behave with two engines out. But even the preliminary analyses seemed to indicate conclusively that the vehicle would tumble out of control. They had a euphemism in the space program for such unlikely failures: “a bad day.” You didn’t bother to plan for bad days. By definition, they were the kind of thing that the gods did to you sometimes, and the best thing to do was go home and have a drink and come back the next day to pick up the pieces.

“You sure, Booster?” The language of the MOCR was one of the most economical in the world, for encapsulated in those three words was a long list of questions. “Are you really sure that the Saturn V is under control, Booster?” Charlesworth was asking. “Are you sure that you shouldn’t hit that abort switch, Booster?” “Are you sure you know what you’re doing, Booster?” All of that and more was in those three words. But from his tone, Charlesworth might have been asking Booster whether he really wanted another cup of coffee.

They managed to complete most of the maneuvers in the flight plan, and the spacecraft was returned safely to earth, but there remained two sobering, unassailable facts: The pogo in the first stage was so severe that a crew might have been injured, had to abort, or both; and three separate engines had failed. Later that day, in the early afternoon, Martin Luther King was shot and killed as he stood on the balcony of the Lorraine Motel, and the United States moved from a time of troubles to one of domestic crisis. The rest of the world paid little attention to the Apollo 6 flight one way or the other. Insofar as anyone noticed, it looked like a success—NASA announced, accurately, that all of the mission’s major flight-test objectives had been achieved. Within NASA, Apollo 6 was deeply disquieting.

Had there been men on board Apollo 6, the crew probably would have aborted the mission during the pogo, when they would have been so violently banged around that they couldn’t have operated the spacecraft. If the pogo hadn’t happened, Charlesworth probably would have had the crew abort when the two engines on the second stage shut down. It was all right for Wolf to wait and see what happened with an unmanned vehicle, but it would have been dangerous to do so with a crew on board. It was in this context that, shortly thereafter, George Low decided that the next launch of the Saturn V should carry men—that it should carry them, in fact, all the way to the moon.

On November 4, Mueller sent a letter to Bob Gilruth urging one long last look. “There are grave risks to the program as a whole, not just to the Apollo 8 mission,” he wrote. He was satisfied that the risks “from a purely technical aspect are probably reasonable and acceptable,” and he recognized that “the greatest single advantage” of flying Apollo 8 to the moon was the way it had galvanized people. “Yet,” Mueller pointed out, “you and I know that if failure comes, the reaction will be that anyone should have known better than to undertake such a trip at this point in time.”

Entry was known terrain, whatever the new complexities, whereas consigning a crew to lunar orbit was not. Mayer could understand why it seemed tricky to a layman. It was comparable to taking a rifle outside his office in Building 30, he would acknowledge, and aiming it at a basketball in downtown Houston, some twenty-six miles away. Actually, it was even tougher than that, more like aiming at a point that was one-sixteenth of an inch to the side of the basketball. So, yes, Mayer could see why a layman might think it was tricky.

It was not quite 4:00 A.M. on December 24, 1968. In the viewing room, a hundred people were packed into a space meant for seventy-four. One of them was Robert Sherrod, a well-known journalist who had been covering the space program after a colorful career as a war and foreign correspondent that had begun before World War II. “I looked up at the big center screen beyond the banks of flight controllers’ consoles,” he wrote later. “Suddenly the familiar map of the earth vanished from the big plastic screen, and in its stead a map of the moon appeared. The effect was overwhelming. I can recall a few similar heart-stoppers in a lifetime of looking and listening—the view of Angkor Wat’s timeless, brooding temples by moonlight, hearing Giulietta Simionato leading the Anvil Chorus at the Met, seeing for the first time the coast of Asia from a bomber after more than three years and many blood-drenched battles across the wide Pacific. None of these equaled the shock of seeing that illuminated map on the screen.”

There were five key phases for the flight: launch to orbit, trans lunar injection, lunar-orbit insertion, trans-earth injection, and entry. During the first three, there had been a way to abort and go home. It was the fourth, T.E.I., trans-earth injection, that had worried people since August. This was the moment that some said had caused Webb to leave NASA. It was quite simple: The S.P.S. engine had to work, bringing the crew out of lunar orbit, or else the crew would circle the moon, with a nice, clear radio link back to earth, for about nine days until their oxygen was exhausted and they died.

Caldwell Johnson, speaking as a designer of the spacecraft, explained it. He knew about the checks and balances and all the other people working on the design who were bound to catch a major error. But still, he said, “after a while, you really become appalled that you’ve gotten yourself involved in the thing. At first, it’s an academic exercise. And then the first thing you know, there’s people building these things, and they are really getting ready to do it, and you start thinking: Have I made a real bad judgment somewhere, and the damn thing is just not going to work at all?”

For many of the people in the Apollo Program, Apollo 8 was the most magical flight of all, surpassing even the first landing of Apollo 11. For some, like Mike Collins, Eight’s momentous historic significance was foremost.

There were only four days left in that sad and chaotic year of 1968. Things hadn’t gotten any better after April 4. Since then, Robert Kennedy had been shot and killed, the nation’s cities had been torn by riots and burnings, and unprecedented bitterness over the Vietnam War divided Americans from one another. Still, at that moment all Loe could think of to say was, “I’m just standing here being very proud to be an American.”

The lunar module was thus a formidably complex vehicle, a self-contained system designed to perform multiple functions under unique, never-before-experienced circumstances. Apollo 9 was the first of the missions to attempt to operate it.

Apollo 9, the D Mission in Owen Maynard’s alphabet schedule, was known within the program as the connoisseur’s mission.

Demanding, dangerous, crucial to the success of the program, and also perhaps the most anonymous of the Apollo missions, Apollo 9 was launched on March 3, 1969, carrying McDivitt, Schweikert, and David Scott. The mission lasted ten days, during which the LEM separated from the command module, fired both its descent and its ascent engines in a variety of modes, and performed without a hitch. Outside NASA, the media and the public paid little attention. Within NASA, Apollo management penciled in the G Mission for a July launch.

So despite some spirited arguments within NASA itself, Apollo 10 with a crew of Tom Stafford, Gene Cernan, and John Young blasted off on May 18, 1969. Three days later, Stafford and Cernan undocked the LEM they had named Snoopy from the command module and descended toward the lunar surface.

Finally, there was the “flying bedstead,” a free-flying machine that had given everyone scares for the last year. First Armstrong and then another test pilot had been forced to bail out when the machine crashed. It had been grounded for many months, and only because Armstrong insisted was he permitted to resume using it for practice in the spring of 1969. To some degree, design faults made the flying bedstead liable to crash, but there was more to it than that: A machine that truly mimicked the task of flying a lunar module was going to be hard to fly.

Two mistakes were made. First, no one realized that withholding the information didn’t make the computer stop trying to read the rendezvous radar. All it did was give the computer the impossible task of trying to find a match for a meaningless angle whose sine was 0 and whose cosine was 0; and because computers do not know when tasks are impossible, they just keep trying to do what they have been told. The second mistake was in failing to send down another Crew Procedures Change Sheet canceling the previous instruction to set the rendezvous radar mode switch to Auto—no one thought it was necessary, because (or so they thought) the original change had been disabled. These two mistakes nearly caused the first lunar landing to fail.

On Wednesday, July 16, 1969—2,974 days after John F. Kennedy asked the United States to commit itself to a lunar landing, 169 days before the deadline he had set—Apollo 11 was launched. The Saturn V carrying Neil Armstrong, Buzz Aldrin, and Michael Collins lifted off from Pad 39A at 9:32 A.M., Eastern Daylight Time, the precise moment selected months earlier.

“We . . . we’re go on that, Flight.” It was nineteen seconds since he had first told Kranz to stand by. Steve Bales, twenty-six years old, with some advice from a twenty-four-year-old, given nineteen seconds to think it over, told Gene Kranz, Chris Kraft, General Phillips, Administrator Paine, President Nixon, and the world—and, not incidentally, Buzz Aldrin and Neil Armstrong—“Ignore the computer and trust me.” “We’re go on that alarm?” Kranz wanted to make absolutely sure. Again Bales stammered. “If . . . if it doesn’t recur, we’ll be go.”

“Contact light. Okay. Engines stop.” Buzz Aldrin followed this with the string of procedures he and Armstrong were carrying out, “safe-ing” the vehicle. “We copy you down, Eagle,” Duke said. “Houston, Tranquility base here,” Neil Armstrong announced. “The Eagle has landed.” “Roger, Tranquility, we copy you on the ground. You’ve got a bunch of guys about to turn blue. We’re breathing again. Thanks a lot.” Even as CapCom was saying to Eagle, “We copy you down,” Kranz was already on the loop to the controllers: “Okay everybody. T1, stand by for T1.”

The events of the rest of that day were watched on television by a worldwide audience estimated to be in excess of a billion people. Neil Armstrong and Buzz Aldrin told flight director Milt Windler that they wanted to postpone their planned rest period and proceed directly to the E.V.A. Kraft, not surprised that the crew didn’t feel sleepy, agreed.

At 9:56:15 P.M., Central Daylight Time, July 20,1969, Neil Armstrong hopped from the bottom rung of the LEM’s ladder onto the lunar surface, proclaiming, “That’s one small step for a man, one giant leap for mankind.” That, at least, is what Armstrong intended to say. A communications glitch made it sound as if he had said “That’s one small step for man, one giant leap for mankind.” Armstrong was nonplussed when he returned and found how his historic first words had been heard, pointing out that without the “a” the sentence made no sense.

Once that question had been defined, SPAN went out to search for an answer. If it wished, SPAN could go directly to the manufacturers’ plants. During missions, North American in Downey, Grumman on Long Island, and M.I.T. in Cambridge each had rooms with engineers standing by twenty-four hours a day, with access to all of their plants’ archives and testing facilities. The dozens of subcontractors scattered around the country also maintained on-duty staffs. If, for example, Grumman wanted to know the testing history of a particular LEM battery manufactured by Eagle Pitcher in Joplin, Missouri, somebody would be standing by in Joplin who could give Grumman the answer.

And there, finally, Arabian’s view of the cosmos rested: He had faith in hardware systems and in designs that obeyed the laws of physics, and a deep distrust of human performance. “See, the brain is very clever,” Arabian said to all who would listen. “It can perceive things, it can create things, and all that. But it’s the most undependable, unreliable, unpredictable device that exists.”

The anomaly that caused the highest pulse rates during Apollo 11 occurred a minute after the landing. It was not mentioned in the press coverage or in the official NASA history, probably because nothing came of it, but for a few minutes it scared the living daylights out of the handful of people on the ground who knew what was happening. On TELMU’s screen in the MOCR and on the lunar module systems screen in SPAN, readings showed that pressure and temperature were rising alarmingly in one of the descent stage’s fuel lines. After the engine had shut down, a blockage had apparently occurred—almost certainly, Grumman’s Tom Kelly in SPAN believed, because liquid helium had frozen a slug of fuel left in the pipe. As they watched the screens, the residual heat from the engine (which had been operating at 5,000 degrees Fahrenheit when the Eagle had landed) was moving up toward the frozen fuel, and the question bothering Kelly was what would happen when the trapped fuel suddenly got much warmer. “There’s no telling what it will do,” he told Low, who by this time was on the phone with Kelly. The fuel was unstable when heated, and Kelly saw a real possibility that the frozen fuel would explode like a small hand grenade.

L.O.R. had been considered so unrealistic in 1961 because of the maneuver that was now about to take place for the first time: a launch-to-rendezvous by a spacecraft 240,000 miles from home. The first reason why that prospect had been so forbidding is that spacecraft cannot move sideways any great distance. They can move up, down, forward, or backward, but for practical purposes they are locked into the plane in which they have been launched—sideways movement against that momentum is extremely costly in propellants. Therefore the first constraint of space rendezvous is that the planes of the two rendezvousing spacecraft be virtually identical. This requires, obviously, great navigational precision during powered flight to orbit.

Then came Conrad’s next message: “I got three fuel cell lights, an A.C. bus light, a fuel cell disconnect, A.C. bus overload, 1 and 2, main bus A and B out.” Conrad’s voice was calm but strained. He was reporting that, for all practical purposes, the spacecraft was inoperative: all electrical power was down except for the emergency batteries that ordinarily were used only for entry. Conrad had barely finished his sentence before Griffin was on the loop to his EECOM, John Aaron. “When things start going to worms,” Aaron would point out later, the EECOM was the most likely person to know what was going on. Only something in the electrical system that EECOM monitored could be causing the multitude of difficulties that Twelve was encountering. “How’s it looking, EECOM?” Griffin asked. He fully expected Aaron to come back with a recommendation to abort.

The reason Twelve was able to get to orbit was that the guidance system for the Saturn V, buried within the Instrumentation Unit at the top of the S-IVB stage, was unaffected by the lightning. If its platform had tumbled, the Saturn would have gone out of control within a few seconds. Part of the reason the spacecraft was so affected by the lightning while the Saturn was not involved the spacecraft's greater exposure—it was positioned like the tip of a lightning rod—and part of it was luck, as Arabian emphatically pointed out. Neither the launch vehicle nor the spacecraft had been designed with lightning in mind.

But suppose the situation had been posed as a scenario on the ground, when writing mission rules. Under those circumstances, would Tindall’s Mission Techniques meetings have come up with a rule saying that if the spacecraft is hit by lightning and the electrical system goes down and the platform tumbles, our Standard Operating Procedure will be to conduct an hour-and-a-half check and, if nothing seems wrong, continue? Well, said an Apollo veteran, now a senior NASA manager, maybe not. Or suppose, twenty years later, after the Challenger accident, that a comparable situation were to occur with the shuttle. Would NASA go ahead with the equivalent of a translunar injection? He laughed aloud at that one. Not a chance. But this is now, he said. That was then.

Now came Schiesser’s imaginative leap: Suppose that we forget about trying to model perfectly the effects of the mascons, he suggested, and concentrate instead on modeling what the shifts in frequencies should look like during the course of a landing at point X, from the time that the LEM appears around the edge of the moon until touchdown. With this predicted pattern of frequencies in front of us, we can watch what the actual frequencies are, and calculate the difference. Then we can use the difference between the predicted and the actual frequencies to decide how far off target we are. It was, Tindall reflected, “astounding”—simple and obvious after you heard it, as elegant solutions seem always to be.

Then, as Conrad and Bean streaked across the face of the moon under powered descent, the three of them began figuring out the value for Noun 69—by hand. The Control Center’s computers didn’t know how to do something as simple as multiply two numbers, Schiesser said, and they hadn’t bothered to bring in a mechanical calculator. They scratched out their calculations, passed the number to the Trench, who gave it to Flight, who told CapCom to transmit it to the crew.

When Apollo 13 lifted off on April 11, 1970, manned space flight was one day shy of the ninth anniversary of Gagarin’s flight. In the intervening years, the actual flights had been unexpectedly safe. Thirty-seven times, men had sat atop rockets and been blasted off into space; thirty-six times, they had returned safely. Only once—if one discounted rumors of unacknowledged Russian catastrophes—had a flight resulted in a fatality: In April 1967, Vladimir Komarov of the Soviet Union had perished after his parachutes failed to deploy properly during an emergency entry. Of the thirty-six crews that had returned safely, the Americans had launched twenty-two—six in Mercury, ten in Gemini, six in Apollo.

The crisis on Thirteen began on the third evening of the flight. The command module Odyssey and the lunar module Aquarius were outward bound, 205,000 miles away from the earth. Jim Lovell, veteran of two Gemini flights and Apollo 8, at that time the most experienced American astronaut, was commanding the flight. Fred Haise, the lunar module pilot, was making his first space flight, as was Jack Swigert, the command module pilot.

At nine o’clock that night, Houston time, Lovell and the rest of the crew completed a television broadcast. None of the three networks had carried the show—by April 1970, flights to the moon were old hat, as were ill-lit pictures of whiskery astronauts floating around in their spacecraft. The main audience had been the people at M.S.C., watching on the television monitors scattered around the Center. In the MOCR, flight director Gene Kranz had permitted the O&P officer to throw the television image onto one of the screens on the front wall. With the spacecraft safely on course, the LEM docked with the command module, and nothing much to do for twenty hours until L.O.I., this was one of the laziest shifts during a lunar flight.

Seymour (Sy) Liebergot, a Californian, almost elderly by MOCR standards at the age of thirty-four, was the White Team’s EECOM for Thirteen. As the television show ended, he got onto the loop to Flight to ask for a cryo stir. “Cryo” referred to the cryogenics: two tanks each of liquid oxygen and liquid hydrogen that produced the spacecraft’s electricity, oxygen supplies, and water. Chilled to their liquid state because that was the only way to store a sufficient amount for the lunar journey, the O2 and the H2 (as the controllers referred to them) were fed into three fuel cells, which converted them to electricity and, as a by-product, drinking water. The electricity passed into two main electrical buses, A and B, from which the equipment on the spacecraft drew power.

At 9:08, the conversation on the EECOM loop, which until then had been quiet and desultory, suddenly changed. In the background, on the air-to-ground loop, Swigert could be heard saying, “Okay, Houston, we’ve had a problem.” Immediately thereafter, Larry Sheaks cried out indignantly, “What’s the matter with the data, EECOM?!” “We got more ’n a problem,” chimed in Dick Brown. Liebergot himself was now looking at a second screen on his console, called “CSM EPS HIGH DENSITY,” which showed the status of the electrical system. “Okay, listen you guys,” Liebergot said to his back room, “we’ve lost Fuel Cell 1 and 2 pressure.” George Bliss ran his eyes over the cryo screen, and then reported the rest of it: “We lost O2 Tank 2 pressure. And temperature.” The crisis had begun.

“Okay,” said Kranz. “G.N.C., you want to look at it and see if you see any problems?” A hardware restart indicated some unusual event that the computer had detected and was checking. Then Lovell’s voice stopped Kranz short: “Houston, we’ve had a problem. We’ve had a Main B Bus undervolt.” An “undervolt” meant a substantial reduction of power into Bus B, jeopardizing the equipment running off it.