First Man

by James R. Hansen

  Late in the afternoon of July 5, eleven days prior to launch, Koos had told his technicians to load “Case No. 26” into the simulators. The exercise was not done to educate the astronauts, because the crew sitting inside the LM simulator that afternoon was Dave Scott and Jim Irwin, the backup crew for Apollo 12. The purpose of the simulation was to throw Flight Director Gene Kranz’s White Team a wicked curveball. The White Team was the unit that was to be at the consoles inside Mission Control during the landing of Apollo 11, and Koos knew that the only way to train its members for their high-pressure duties was to put them through the wringer. A sly grin on his face, SimSup told his team, “Okay, everyone on your toes. We have never run this case, so it is going to take a helluva lot of precise timing on our part. This one must go by the numbers, so stand by for my call-outs. If we screw it up, I hope you got a bunch of change ’cause we’ll end up buying the beer!”

  Three minutes into the landing sequence, the devilish SimSup played his wild card: “Okay, gang, let’s sock it to them and see what they know about computer program alarms.”

  The first alarm put to Kranz’s team was code 1201, one of the very ones Apollo 11 would ultimately face. Steve Bales, the LM computer system expert, had no idea what it was. Hurriedly paging through a quarter-inch-thick handbook containing a glossary of LM software, Bales read out “1201—Executive Overflow—no vacant areas.” What this meant, Bales knew, was that the onboard computer was overloaded with data, but the ramifications of the overload were unknown.

  Gene Kranz vividly recalls the thought process that led Mission Control to abort the simulated landing: “Bales had no mission rules on program alarms. Everything still seemed to be working; the alarm did not make sense. As he watched, another series of alarms were displayed. Punching up his backroom loop, Bales called Jack Garman, his software expert. ‘Jack, what the hell is going on with those program alarms? Do you see anything wrong?’ Steve was counting the seconds, waiting for Garman’s response, happy that the crew had not called for an answer. Garman’s response did not help. ‘It’s a BAILOUT alarm. The computer is busier than hell for some reason, it has run out of time to get all the work done.’ Bales did not need to consult the rules; he had written every computer rule. But there were no rules on computer program alarms. Where in the hell had the alarm come from? Bales felt naked, vulnerable, rapidly moving into uncharted territory. The computer on the LM was designed to operate within certain well-defined limits—it could do only so much, and bad things could happen if it were pushed to do things it didn’t have the time or capacity to do.

  “Staring at the displays and plot boards, Steve desperately sought a way out of the dilemma. The computer was telling him something was not getting done, and he wondered what in the hell it was. After another burst of alarms, Steve called, ‘Jack, I’m getting behind the power curve, whatever is happening ain’t any good. I can’t find a damn thing wrong, but the computer keeps going through software restarts and sending alarms. I think it’s time to abort!’”

  Seconds later, Kranz called the abort. Charlie Duke, who was serving as the CapCom for the simulation just as he would be serving as the CapCom for the actual landing, told astronauts Scott and Irwin inside the LM to carry out the abort, which they accomplished successfully.

  The exercise over, SimSup strongly expressed his unhappiness with the outcome in the debrief: “THIS WAS NOT AN ABORT. YOU SHOULD HAVE CONTINUED THE LANDING. The 1201 computer alarm said the computer was operating to an internal priority scheme. If the guidance was working, the control jets firing, and the crew displays updating, then all the mission-critical tasks were getting done.” Turning to Bales, Koos told GUIDO in a more fatherly tone, “Steve, I was listening to you talk to your back room and I thought you had it nailed. I thought you were going to keep going, but then for some reason you went off on a tangent and decided to abort. You sure shocked the hell out of me!” Then, addressing Kranz, Koos made his last stinging point. “You violated the most fundamental rule of Mission Control. You must have two cues before aborting. You called for an abort with only one!”

  Immediately after the debrief Bales pulled his team together in order to figure out where they had gone wrong. Later that evening, he telephoned Kranz at home: “Koos was right, Gene, and I’m damn glad he gave us the run.”

  The next day, July 6, Koos put them through four additional hours of training exclusively on program alarms. At the end of a thorough analysis of computer performance and response times during a host of different alarm conditions, an enterprise that took until July 11, Bales added a new rule to what was already a long list of reasons to abort the lunar landing. The rule, numbered “5–90, Item 11,” read: “Powered descent will be terminated for the following primary guidance system program alarms—105, 214, 402 (continuing), 430, 607, 1103, 1107, 1204, 1206, 1302, 1501, and 1502.”

  Program alarms 1201 and 1202 did not make Bales’s list. In the unlikely event that one or the other popped up during the main event, the lesson from SimSup would not be forgotten.

  When Armstrong and Aldrin reported the first program alarm at 4:10 P.M. EST, Bales and his team of LM computer experts were busy in a back room of the control center studying the data just coming in from the landing radar. It took a few seconds before Jack Garman brought the alarm call to Bales’s attention. “Stand by, Flight,” GUIDO told Kranz over the flight director’s communication loop. Charlie Duke quickly echoed that the alarm was a 1202. Then musing aloud, Duke said almost incredulously, “It’s the same one we had in training.” Instantaneously, the coincidence dawned on Kranz: “These were the same exact alarms that brought us to the wrong conclusion, an abort command, in the final training run when SimSup won the last round. This time we won’t be stampeded.”

  Mission Control knew that each alarm had to be accounted for, because if an alarm stayed on, the onboard computer could grind to a halt, possibly forcing an abort. But in and of themselves, without additional trouble, neither alarm 1202 nor the later-occurring 1201 required an abort. “We’re Go on that alarm,” Bales told Kranz as quickly but clearly as he could from the back room after the alarm came up the first time. “He’s taking in the radar data.” When 1202 came up again, Bales responded even more quickly. “We are Go. Tell him we will monitor his altitude data. I think that is why he is getting the alarm.” When the new 1201 alarm popped up, it brought the same speedy response from Bales: “Go…same type…We’re Go.”

  Despite Mission Control’s decisiveness in keeping the landing going, it would have been helpful to Armstrong and Aldrin if they had experienced the program alarm simulation themselves, as part of their own training. “We did have some computer alarms in the simulations we were put through, but not these particular ones,” Armstrong notes. “I can’t tell you how many alarms there were, but there were quite a number—maybe a hundred. I didn’t have all those program alarms committed to memory, and I’m glad I didn’t.” Knowledge of so many alarms would have just cluttered his brain with a type of information he did not absolutely need to know—as long as the guys at Mission Control knew what to do if any of the myriad program alarms sounded.

  Still, one would imagine that someone would have thought to brief the Apollo 11 crew about any important results from simulations that occurred after they left Houston for the Cape, or at least have mentioned them informally to both Neil and Buzz. But the astronauts’ recollection is that this never happened.

  “Neil, in the days before launch, did anyone, perhaps Charlie Duke, tell you about a simulation back in Houston involving LM computer overloads that might happen during the last minutes of the descent?”

  “I had heard or remembered somewhere that such failures had been put into the simulator.”

  “But had you been told that Mission Control in this case had unnecessarily aborted the simulated landing and then figured out afterwards that an abort was not commanded if such-and-such a computer program alarm went off but there was no other problem? You don’t recall hea
ring about that?”

  “I don’t.”

  “Would that have made a difference in how you reacted to the alarms when they actually occurred in Apollo 11?”

  “Well, it would have been helpful to have known that.”

  Aldrin categorically does not remember hearing anything at all about the last-minute simulation: “I didn’t know anything about it until I heard about it a year or two after the flight. That was the first I knew that anyone had experienced that in any training.” On the other hand, Buzz feels that Neil must have heard something about it before the launch: “I believe that people briefed Neil on that, so Neil knew that there was something like that that could come up.”

  “So, Buzz, when the program alarms hit the two of you during the landing,Neil had some recognition that this was a possibility and that it had been worked on in a simulation, but you didn’t know anything about it?”

  “That’s right. I didn’t know anything about it. And that was not a good situation. I should have known where the flag was on that. I should have known a few other things. But that’s the communication reticence that existed with Neil, and I didn’t know how to change that.”

  “But wouldn’t it have been good if you had both known the results of that simulation, so you could both react the most reasonably if such a program alarm actually occurred?”

  “I agree, but I didn’t find out about it until a year or so after. Then, it was too late to make an issue of it, because it would have brought up things in somebody’s methods that were not enhancing, and I sure didn’t want to do that.”

  As it was, the principal effect of the actual computer alarms on Armstrong was that he gave more of his time and attention to the alarms than he would have liked: “I had the obligation to make sure that I understood what was happening and that we weren’t overlooking something that was important; so in that sense, yes, sure, it was a distraction, and it did take some time. The alarms as they came prevented me from concentrating on focusing on the landmarks. Had I been able to spend more time looking out the window and identifying landmarks, I might have had a better position on just precisely where our landing location was.” But never during the alarms did Neil think he might have to abort, because he knew instinctively as an experienced test pilot and well-trained astronaut that such alarms did not command an abort if everything else about his flying machine was in order. “In my mind, the operative indicator was how the airplane was flying and the information that was on the panel. If everything was going well, going how you expected it to go…I wasn’t going to be intimidated by one computer yellow light.”

  As Neil shifted his focus to the lunar surface they were fast approaching, he didn’t see craters or patterns of craters that he recognized, but, under the circumstances, it wasn’t a big concern. For hours on end during training, Neil had studied different maps of the Moon, pored over dozens of Lunar Orbiter pictures of the surface, and scrutinized a score of high-resolution photographs taken by Apollo 10 marking the way, landmark by landmark, down to the Sea of Tranquility. “The landmarks that I was looking at out there were not ones that I had studied or remembered well enough to know just where we were, but I was pragmatic about it. I didn’t find it surprising or worrisome that we ended up some other place. Anyway, it would have been surprising on the first try for a lunar landing if we had ended up anywhere very close to where we wanted to be. I didn’t count on that at all. From an objective point of view, I didn’t particularly care where we landed as long as it was a decent area that wasn’t dangerous. It didn’t make a lot of difference where it was. I thought we might just have to find somebody’s backyard to land in.”

  Because his attention had been directed toward clearing the program alarms, not until the LM got below 2,000 feet was Armstrong actually able to look outside without interruption at the landing area. What he saw as they dropped the next 1,500 feet was not good:

  The onboard computer was taking them right toward the near slope of a crater the size of a football field. Later designated West Crater, it was surrounded by a large boulder field. Some of the hefty rocks in it were the size of Volkswagens.

  “Initially, I felt that it might be a good landing area if we could stop just short of that crater, because it would have more scientific value to be close to a large crater. The slope on the side of the big crater was substantial, however, and I didn’t think we should be trying to land on a steep slope.

  “Then I thought that I could probably avoid the big rocks in the boulder field but, never having landed this craft before, I didn’t know how well I’d be able to maneuver in and between them to a particular landing point. Trying to get into a pretty tight spot probably wouldn’t be fun. Also the area was coming up quickly, and it soon became obvious that I could not stop short enough to find a safe landing spot; it was not the place where I wanted to be landing. Better to have a larger, more open area without the imminent dangers on all sides.”

  Approaching 500 feet, Armstrong took over manually. The first thing he did was tip the vehicle over to approximately zero pitch, thereby slowing the descent. By pitching nearly upright, he also maintained his forward speed—some 50 to 60 feet per second—so that, like a helicopter pilot, he could fly beyond the crater.

  Now that Armstrong was headed beyond the crater, he needed to pick a good spot to land, a potentially difficult enterprise given the very peculiar lighting conditions affecting the Moon’s surface, which there had been no way on Earth to simulate. “It was a great concern,” Neil recalls, “that as we got close to the Moon, the reflected light off the surface would be so strong, no matter what angle we came in on, that a lot of our vision would be wiped out, seriously affecting our depth perception.”

  Fortunately, NASA’s mission planners had given plenty of forethought to the photometrics involved. They had concluded that, for optimum depth perception, Eagle needed to land at a time of “day” and at an angle that produced the longest possible shadows. Where there were no shadows, the Moon looked flat, but where shadows were long, the Moon looked fully three-dimensional. An astronaut could then perceive depth on the lunar surface very well: he could detect differences in elevation; he could easily identify the accented shapes and forms of peaks, valleys, craters, ridges, and rims. The ideal condition occurred for the trajectory of the LM when the Sun was 12.5 degrees above the horizon. That was the time when Armstrong and Aldrin would have adequate light over the area and still strong depth-of-field definition: “We could pick out bumps and craters and things like that so you could pick out a level landing area.”

  With Armstrong able to see quite well out into the area beyond the crater, bringing the LM down became a matter of Neil’s piloting abilities, pure and simple. It was here that Neil’s time in the LLTV really paid off, for he needed to bring the Eagle to a touchdown point not simply by hovering and dropping vertically but by sweeping down for another 1,500 feet at a relatively fast speed. “In the Lunar Lander Training Vehicle I had done some of that sort of maneuvering. It was a matter of using those types of techniques and traversing over the ground. If I had had a little more experience in the machine, I might have been a little more aggressive with how fast I tried to get over the crater, but it didn’t seem prudent to be making any very large moves in terms of attitude. I just didn’t have enough flying experience in the machine in those conditions to know how well it was going to react and how comfortable I would be with it. Fortunately the LM flew better than I expected. So I certainly could have gotten away with being a little more aggressive to moving more smartly over and away from the bad area into the better area, which might of saved us a little fuel.”

  Normally in flying, “landing long” was not a bad idea, especially when the landing was to take place on a runway where the condition ahead was known for a substantial distance. But when the landing was to occur on the rocky, pitted surface of the Moon, landing long brought in more unknowns than landing “short” in an area where the pilot had already seen the hazards involved
. “If you don’t like what you see,” Aldrin explains, “there are four classes of alternatives: left, right, down or short, or go over. Overwhelmingly, the less traumatic one is to go over, even though there may be some question, ‘Well, if I go over, then I don’t know where it is. Whereas if I land short, then I know where it is. I’m not on it, I’m in front of it.’ As I try to reconstruct it, going right is a hairy thing; going left is a hairy thing; and coming down and stopping short…You might drive yourself into a…You know, it’s just a bad deal.” Armstrong concurs: “You might get down there and find, ‘Jesus, I’ve got a terrible situation.’” “So the natural thing to do,” Aldrin continues, “is to fly over.” “Extend it,” adds Neil. “We had to pick a spot, and we didn’t know how much visibility we would lose as we got closer down to the surface. We wanted to pick a spot that was pretty good while we still had about a hundred and fifty feet of altitude.”

  Seeing the LM’s shadow was helpful because it was an added visual cue of how high they were. Buzz estimates today that he first saw the shadow at around 260 feet: “I would have thought that, at two hundred sixty feet, the shadow would have been way the hell out there, quite long, but it wasn’t. I could tell that we had our gear down and that we had an ascent and a descent stage. Had I looked sooner, I’m sure I could have something identified as a shadow at four hundred feet, maybe higher. Anyway, at the lower altitude, it was a cue that was useful but, of course, you had to have it out your window,” which Neil did not. During the final stages of the approach, Armstrong was flying with the LM rotated to the left. As a result, the spacecraft structure over the hatch was blocking his view of the LM’s shadow.