Jean kranz had a prolific career as a nasa flight and Missions Operation director. He was acting flight director when the apollo 11 astronauts landed on the moon, and as lead flight director of the apollo 13 mission, he had a significant role in guiding three astronauts back to earth after an explosion on the spacecraft. This is part one of a oral history interview landing flight director, werent you. You were in charge of that. You took part in the whole thing. lets go over apollo n unidentified speaker 11. A big project. Theres many things that stand out. A person says where were you when . I sure had an awful lot of great breaks in my life. I mean, whether they be in college, whether they be in flying airplanes, but one of the ones that i remember that is related to apollo 11 in a very direct fashion is the day i got the assignment to do the landing phase. Cliff charlesworth was the lead flight director and one of the responsibilities of the lead flight director is to identify which flight director is going to cover which phase of the mission. And moving in there, this was the First Mission where in apollo now where loni, charlesworth and myself who had been flight directors on gemini were actually coming back together again. So, you had probably the three most experienced people at the console. And it was a question of who was going to get to do what . And loni had been to the moon a couple of times. Charlesworth had launched saturn. I had the lunar module experience. You had no particular driver that says this person ought to be doing this phase of the mission. And i was division chief at that time and kraft had been really on top of us to nail down who is going to do what until finally the apollo 9 mission we all managed to get together and charlesworth had to make the calls. And i called him and i said, cliff, we got to make a decision on which flight director is going to cover which phase of the mission. And this is probably the most anticlimateic meeting i ever had in my life. He looked me straight in the face and said ill launch it and ill do the eva. So that only leaves the landing and the lunar liftoff. I think glen is going to do the lunar liftoff so you got the landing. It was all over in about 60 seconds. And, you know, each flight director i dont think theres any question everybody wanted to do something for the first time. And the beauty of the Apollo Program was is there were enough firsts to go around for everybody but when it came time for the first Lunar Landing mission, i really got to respect cliff for saying, hey, you take the job instead of me. And i think he gave me the job principlely because i had spent most of my time with the lunar module people and i happened to have a little more experience in the lunar module than any other guy and it was a totally unselfish decision and i think this is the way the flight directors always try to work. We always try to figure out whats the best chemistry between flight director, team and mission to make sure the job gets done. And it worked. It had to work. There was no question, every mission in apollo had a large number of firsts. and every mission had a very visible profile from the standpoint of media. If you missed the slightest thing there was always this question somebody asked you at a press conference is the Lunar Landing in jeopardy . And fortunately, as we went through these Early Missions and we only had a single shot at each one of these so they all had to work. You can look at them straight in the eye and say no, were on track, well get the job done. By the time you got to apollo 11, the media coverage, the external pressures were high. This is one area where cliff charlesworth, again, as lead flight director, one of their roles was to try to provide the external focus. So he covered the majority of the Mission Briefings of a technical sense. Even covered many of the media briefings. So basically he kept the pressure off myself and loni so we could get ready for the jobs that we needed to do. There was no doubt as we were approaching july 20th that we were doing something no one had ever done before. Did you feel a lot of pressure . Did it worry you . Again, in retrospect i would say yes, but when you when you start feeling the pressure what you do is you find some way to keep your focus so that basically the pressure moves into the background. There was so much to do to get ready for this first Lunar Landing that you just immersed yourself in the job and the pressure faded into the only time i felt pressure during the time i felt intense pressure and maybe i can say this, we had it was as a result of our training and the consoles here at Mission Control there used to be a phone directly behind the flight directors. And routinely during training runs the Program Manager and chris Kraft Division chiefs throughout the center had squawk boxes in their offices and if they ever wanted to hear what was going on in Mission Control they turned on their squawk box and they could hear everything. You would turn even these squawk boxes and its going along in the background while having your meetings or making telephone calls or whatever. In training, the first month of preparing for the Lunar Landing really went pretty well. It seemed we had a hot hand. We come off the apollo 9 mission. We had achieved all of our objectives tlunar module people had done well on apollo 10. And we proceeded into the training process and it seemed that want, boy, every time the training folks threw us a curve we came up with the right solution. Then the training boss, dick cous must have looked at us and said that team is too cocky. That team needs to get a few lessons. He called his team up and put the screws to these guys. We ended up now in our second month of training and really only training roughly about one day a week. Second month of training we had a particularly bad day where we couldnt seem to do anything right. Learning to land on the moon you have a time delay of about three seconds. So anything you see and by the time you can respond and voice up instructions to the crew youre three seconds behind on whats happening aboard the spacecraft. As you get down to the surface of the moon theres what you call a dead mans box. Every airplane landing theres some point no matter what you do, pit the throttle to the engines, youll still touch down before you come back off the ground again. We really had not defined very well this dead mans box as youre coming down to the surface of the moon because its a very complex geometry you have to define. What kind of attitude are you. Basically many parameters. On top of that add the lunar delay it can get bad quick. We went through a bad, bad day. We crashed and crashed and then to avoid crashing we would become unnecessarily conservative and abort when we could have landed and by the end of the day we felt pretty bad and about that time chris kraft calls up on the phone and from his initial comments i knew he had been listening to the simulations and i knew he was watching us struggle. And he said is there anything i can do to help you . Well, there wasnt anything he could do to help me. I mean my team had to find the right answers, we had to find the right timing, right chemistry, right on down the line. And for the first time in this entire process i felt the pressure that hey, maybe our bosses were starting to lose confidence in this team that they had signed to do the mission. Thats when i felt the pressure. My response was very straightforward. I put a switch on his phone so it wouldnt ring any more. He could call all day and just get a busy signal. But we proceeded to dig ourselves out of the pit that we somehow dug for ourselves. We set a different set of parameters in defining this dead mans box. We bought us time. Piece by piece we started putting it back together again until we felt not only we were going to get the job, hell yes, well get the job done. There was no question we would get this crew down to the surface of the moon. And the training process then, i mean we just seemed to be on top of everything until the last day of training and this is, again, i think a very fateful exercise that to this day i thank couse for giving it to us. We have a game plan that we call the mission rules. The mission rules are basically preplanned set of decisions where the controllers in the cold light of day will sit down and take a look at all of the things that can happen in the spacecraft or in the trajectory on a phrase by phase basis throughout the mission. Theres a lot of phases so you end up with a look thats literally four inches thick. The controllers have come to the point where weve exercised these. Weve proved them right. The training people looked and they saw one entire area that wasnt treated in the rules. And it was associated with various alarms that were transmitted from the spacecraft computer down to the ground. And in the final day of training, which i had expected would sort of be like the graduation ceremony, they would give us some problems, give us tough problems but not give us anything that would kill us. Well that wasnt their approach to doing the job. In the final training exercise, they gave us a set of problems on board the spacecraft. We started off high and on the way down we started seeing a series of alarms coming from the spacecraft and there are two types of alarps. One of the alarms said hey im too busy to get all of the jobs done so ill revert to an internal priority scheme and ill work off as many things as i can in this priority scheme until the clock runs out and then ill go back and recycle to the top of this priority listing. Its going to get the job done. May not be updating displays. Then if these type of alarms continue for a sustained period of time it goes now to a much more critical alarm where the computer halts. They gave us the series of alarms, never seen them before. My guidance officer was flustered, it seemed. He calls the abort. I feel we executed the right decisions. And then the training debriefing, it was said no, we dont think you exercised the right decisions we think you could have land. We think you should have looked beyond that alarm to see if you could have figured out what happened. You acted prematurely. We didnt believe it. But the guidance officer, you never leave anything untested. He says, hey, flight, im going to look at this overnight, ill call together a bunch of people from mit, and well find out what we should have done here. Well i got a call about 10 00 that evening that said the training people were right, we had made the wrong decision, they wanted to do some more training the next day. So, these were two episodes associated with the training for the mission. One where management got involved when we were having we were struggling. When i felt pressure. The second time is when i found out hey we didnt have everything wrapped up as well as we should have, we had some loose ends and now the crew was going down the cape, we were weeks from launch. These are the two times i really felt pressure during the course of this mission. But i didnt feel anything. Finally they launched. They were coasting out towards the moon. Your crew were still operating. Getting ready for the big event. During that time . Several interesting things. This is my First Experience with the translunar phase of the mission because i had worked 7 and 9 but never had this continuous communication. It was absolutely marvelous to sit in Mission Control now and see the spacecraft on a 24 hours a day throughout this entire transit period. So, from my standpoint we used this to continue binding ourselves together as a team. I would go over through every one of the telemetry measurement italked the trans lunar phase of the mission was that final period to pull all the pieces together to go over any of the little items that maybe didnt close out as well as you should have, to maybe go through the final discussion on the mission rules, would we really do this if this happens kind of thing. But its a time to continue to build this chemistry that must exist between flight director and team and crew when you have to make a very short term rapid Time Critical irrevocable type decisions. Because once we got to the surface of the moon, i mean once we got to the point we were getting ready to land on the moon, theres only three options. Abort, crash or land. Those options are pretty awesome when you think about it. Hey, were not only in this particular mode of operation now, were going to be doing it in front of the entire world, and its now to the point where you look to each other for this confidence you need to work through any times when you might have just the slightest tinge of doubt. Generally the slightest tinge of doubt comes when youre tired. Thats the magic of this Flight Control team that we have here. It is so selfsupporting you know in Mission Control when a person needs a little bit of help, a little bit more time to make a decision and this team is so totally focused, its marvelous. Well, all of this paid off eventually because that landing was not a piece of cake. No. The landing, i dont think, there was anything that really prepared us for the intensity of the landing. If i can back up a little bit. One of the mission roles, im talking about game plan, that was given to me exclusively where i had to make a decision is in the preparation for the mission. Headquarters people, the Program Managers as well as chris kraft was concerned that if we would crash and not have enough data to figure out why we crashed, we would be in jeopardy of the, not only losing the lunar probe but the entire program. So, everybody wanted to make sure that there was some formula that would be used by the team to say, okay, we got enough data to continue. I fought this particular rule because they wanted some numbers. I fought this rule all the way through the process of building the rules, going through the review, the mission reviews, et cetera and i want ad very simple one that says the flight director will determine whether sufficient data exists to continue the mission. And thats i just wanted it that simple, it was a subjective call by the flight director. This was batted back and forth until very close to the mission and it was not resolved so i wrote into the mission rules that exact statement the flight director will determine if theres sufficient data to continue. Going back to the landing, this information means voice information and telemetry. As soon as the spacecraft cracked the hill and we were now silently coasting down to the 50,000foot mark below the moon the voice was broken, we couldnt communicate. Nothing was going right. And, immediately, that rule came to mind, do i have sufficient information to continue . But then we would get a bit and i would say ahha we can look at the spacecraft. There were a couple of times where i would make calls for the gono go point. Okay Flight Controllers gono go point. Use the last valid data points you saw. This might be 30 seconds old. So they are making decisions based on stale data. We kept working, trying to figure out what was the problem with the communications, and this turned out to be a Bad Information on the attitudes used in the spacecraft because we were getting some reflections off the kin of the lunar module. But, again, this is too late. We had to try to solve the problem in realtime and again going back to the teamwork. Charlie duke who is myspace craft communicator was looking at the signal strengths. He saw them varying. He also worked the apollo 10 mission. He suggested to don putty, he had the responsibility for the communications and life support on the lunar module, he said don, do you think we could have changed, make an attitude change would that help any . So then we tried that. Fortunately in training we had also worked in relaying voice information from the ground to mining columns back down to the lunar model. We were using every conceivable way to communicate. In the mean time time is marching down to my gono go points. Then buzz aldren is not seeing what hes expecting to see. Again, this is very critical from the standpoint of gyros. Controllers looked up, okay, its looking good. By this time my guidance officer has some packing information and the spacecraft isnt where it should be. I mean its that straightforward. I didnt know whether the data he was getting was bad or it was just bad navigation, or we had some kind of a problem with targeting in the spacecraft but the problem is he really got my attention. He says flight, were out on the radio velocity which is the vertical velocity and halfway to our abort limit. Boy, when you havent started down to the moon and some guy says hey were halfway down to our abort limit it gets your attention. But i said ill keep watching it. Now you got communications problem, navigation problems and youre still trying to struggle into meet all of these windows for making your decisions as youre now saying hey were ready to ignite the engine. We got down to the gono go for start up power dissent, about four minutes prior to the landing point. And, again no reason i had to wave off. The team was working well. We made the go to continue and as soon as we did that we lost communications. So we couldnt tell the crew. Charlie duke relay that the go to continue. Here were getting ready to go to the moon and we cant talk to the crew directly. We keep working through this problem until its time for engine start. Weve had data intermittently. Engine start. Again at the time of engine start we need to capture the telemetry at that point so we know the exact quantity of propellents in the tanks because its being of a bektaffected by the acceleration. So we miss this very valuable point and continue on down and now, from the time we start until the time we land on the moon, it should take about between eight and nine minutes. And this becomes a very intense period where again steve bales, the guidance officer has been trying to figure out whats with this navigation problem that were halfway to our abort limit. He comes back and gives, me a call that really is now a bit more confident, he says were still halfway to abort limit but not growing. He tends to believe that something happened upstream. It might have been a maneuver execution where the engine didnt shut down perfectly. On retrospect we found out after the mission, that the crew had not fully depressurized the tunnel between the two spacecrafts and when they separated the spacecrafts it was like a champagne cork popping out of the bottle. It gave the spacecraft a little bit more speed than it should have, like performing an extremely small maneuver. Over the period of time of the lunar orbit this maneuver placed the spacecraft in a different position than it should have been to start the descent. We didnt know that at the time. We had to figure this out. So now were in the process of going down and were making the calls, everything seems to be gringt going right for a change. We learned to work around the broken communications but it seems to be getting better. Were now at the point where were evaluating the landing radar data. This is an important junction. The lunar module is using the altitude we gave it based on tracking data and our knowledge of the position of the moon. We now have to update that altitude by the real altitude measured by the landing radar. If theres a very large difference between the altitude weve given it and what the radar is seeing they have to smooth it out. You cant make that correction instantaneously. Were in the process of determining whether the landing radar is acceptable to enter into the computer. When we get a call from the crew that theyve had a Computer Program alarm and for a few seconds its just total silence. Nobody has commented on this thing. Weve all heard it. And then the crew comes down and gives a reading on the alarm. Well, its sort of like coming to a fork in the road. Half of my team, in fact most of my team is trying to decide whether to accept this radar and steve bales, my guidance officer is an important part of that decision. But now he has to answer to this Program Alarm kind of thing. For a period of time half the team was moving in this direction tother half starting to move in this direction. I have to pull these guys back. Charlie duke makes a call, can we get a reading on the alarm . Again, steve bales now has studied the alarms as a result of this training exercise. So, now he goes back to this back room controller, tommy gibson says are these the ones we basically reviewed during training i dont see any problems. Do you see any problems . Very rapidly we got to go to continue. Now were working through this. Were accepting the radar lunar data. These alarms are continuing intermittently through the descent. One of the things that steve comes up with that he says hey, it might be related to some of the displays the cruise are using. We tell the crew to back off the very high utilization on boards on altitude and altitude rate and tell them well provide the read ups for them during this period. So this team now is faced with were going to the moon for real. This is not a simulation any more. Its faced with incredible problems that nobody ever really anticipated, we thought whatever happened will be clear cut but far from clear cut and yet this team seems to be getting tighter. The more problems they got, the more effectively they are working. And this almost makes me happy because a Flight Control team is always best when they are working problems. All of a sudden they are now focused on something. From a back room loop and we can identify who said it, a voice came across and said this is almost like a simulation. I started to snicker. Its sort of a point where you mentally back off, now. The intensity is still there but all of a sudden you say hey we licked these problems before well lick them again. We continue down the process. Now communication, were down to the point where were in power pitch forward. Were five minutes off the surface. Communications has improved dramatically. So this worry that was in the background festering and i may have to make a call because we didnt have good data is now out of the back of my mind and all were doing is working these very focused activities. Again, the communications gets very tight. You can now feel the crew has got their landing point identified. They can see it. They can see that if we continue this automatic guidance well land in the boulder field. So we see neil take over Manual Control an he uses an input with his hand controller that redesignates the landing point. And throughout the mission its basically oriented that if i dont do anything different right now this is where im going land. So basically hes redesignated. So we see now as a result of this error in separation of spacecraft were going to land actually about 2 1 2 miles, i believe, from our designated landing site and this is a rocky boulder crater field area. Now neil is working in this area. And all of a sudden you start becoming intensely aware of the clock that says in most of the training runs, we would have landed by now and we havent landed. And uh, oh, it is going to get tight. This is reinforced moments later when my propulsion guy says low level. Well, we dont have a fuel gauge aboard the spacecraft. Once you get to the point when youre in the round part of the tank down at the bottom theres a sensor that says, okay, if the crew is at a hover throttle setting hell have two minutes to go but now in the back room, this is where some of the magic in Mission Control comes in. The crew, when they are actually flying or hovering is above the hover throttle setting. So the crew is throttling up and down here as they are scooting forward across the surface of the moon much faster than we ever execute and i have a controller in the back room that was looking at the squiggles. Hes mentally trying to think, to investigate how many seconds we have remaining of fuel. He got pretty good at this during training. He got to the point where he could nail it within ten seconds. We put a number of a tensecond uncertainty. So whatever number he gave us we were on the safe side. Then carlton calls 60 seconds and the crew still is not on surface of the moon. We have 60 seconds to either land or abort. Charlie duke at this time says we better be pretty quiet in here right now and this has been a mutually agreed on point that our job is to get the job close enough to effect a landing and from then on the only calls well make fuel remaining. We told them 60 seconds and still not down there. Between 60 and 30 seconds we get a call that the crew says kicking up the dust. Then we get the call 30 seconds. Were down to 30 second remaining. Were all watching the clock counting down. About the time the clock hits 17 seconds and it took a few seconds for me to recognize this, we heard lunar contact and this is theres a probe underneath each one of the feet on the lem. When it touches the surface the crew will hit engine stop and fall in the last few feet. You hear that lunar contact and then i hear the crew going through it takes seconds to recognize they are going through the engine shut down, we must be on the surface. And then the only thing that was out of normal throughout this entire process that we had never seen in training was that the people behind me in the viewing room started cheering and clapping and their instructors were to the right of the room, again behind the glass wall and theyre all cheering. And you get this weird feeling, its chilling that it soaks in through the room and i get it, my god, were actually on the moon. And i cant even relish that thought because i got to get back to work. Because we have to make sure, almost instantaneously whether the spacecraft is safe to leave on the surface of the moon or should we immediately lift off. We go through our t1 stayno stay decision. So within 60 second of guesting on the moon i have to tell the crew its safe to stay on the moon for the next eight minutes. And i dont have any voice. Im clanked up. About this time charlie duke is saying, we hear tranqility. Then charlie duke says you have a bunch of us about to turn blue. Im trying to get started. This all happens in seconds. And finally i rap my arm on the console and break my pen and finally get going, get back on track again and in a very cracked voice okay Flight Controllers stand by for p1 stayno stay. We go through this. Make the stayno stay decision. Then a t2 stayno decision. Were focused to make sure its safe to stay here. Then we have to go through a t3 stayno stay. After two hours were safe to be on the moon for an extended period of time. In the mean time the helium has had some, again, something we didnt anticipate from the design, we got some heat soaked back from the engine so the tank of very cold gas is warming up very rapidly. We dont know if it will explode or the release valves will fire but we know we got to stay on our toes throughout this whole process and were in a crisis mode down here while everybody else is still celebrating until finally we see the pressure start to decrease very rapidly. We believe the thing has vented. The relief valves by design have done what they have should have done. For the first time we can power down. Its only after that we can pat each other on the back, but we said today we just landed on the moon. Walking over, i walk over to the press conference with doug ward, and all i really wanted to do was get back to Mission Control because we had made sort of a silly Mission Design decision and nobody believed it that once we get down in the surface well put the crew to sleep. Well we knew and the crew knew and i think the world knew that the crew wasnt going to go to sleep they wanted to get out on the surface and start the exploration. At the time i was doing my stayno stay i had two complete flight crews. The adrenaline in the control room is building up, you can feel it. It was almost like a heavy fog it was so real. And the controllers, and when they came back in the room these guys were going to be here and there was only three options. Either going to land or crash or going to abort. The room goes through almost a ritual. We go through battle short condition where we physically block the Circuit Breakers in this building because now we would prefer to burn up the building rather than let a circuit building open inadvertently. I didnt realize until after the mission when a couple of the controllers really talked about how all of a sudden it was really sinking in that they were now not going to get out of this room until we had gotten our job done. Steve bales was one of the most folk vocal about it, saying you dont really know what youre doing when youve got a 26yearold kid in this room and basically youre going to write in the history books whatever happened today. Then you lock those doors and i realize, i cant leave anymore. I felt i had to talk to my people. I called them on the assistant flight director loop. This is a secret loop that we use only for debriefings. People in the viewing room cant hear it. Its just tied into the people in this room. We use it only when we debrief and weve got real heavyduty talking, somebody didnt do the right thing or somebody has to be chewed out. Its veryp private and personal. I called the controllers and told them how proud i was of this team and the job that we were chosen to do. I indicated that i believed that from the day we were all born, we were destined to meet in this room this day and at this moment and that from now on, whatever happened, we would remember this day forever. We then proceeded to give a few coaching tips. I said whatever happens, i will never secondguess any of your calls. Now, lets go out, lets go land on the moon. Terminated the loop. All of the people in the viewing room were probably wondering what the hell we were talking about. And thats a blank on the tapes. But, again, steve bales, the guidance officer, came up and he said how how important this settlingdown process was. Not only to him but actually to his people in the back room. Since he was such an intense part of the job, steve was a very interesting guy. He was what i would say the prototype of the nerds or the geeks that work in the computer world today. He was the first guy working with the state of making absolutely irreverseable, timecritical decisions. About four years out of college, he had grown up in the business. Steve, you could feel his emotion. When we would pull the room and go through his go, gonoesnogoes, you could feel this go and it ricochetted. There was a time as we were actually almost to the surface when we did our final go, nogo, he was so go that i almost chuckled. He was so intense in doing the job. But this is a group of young people who had signed up to do a job. It was generally the first generation in their entire family who had ever gone to college. Most of these people were midwesterners. Their work ethic was absolutely specktacular spectacular. I had no doubt this team was able to do this job. They were young . Yeah, they were young. Average age was 26. I have a picture. It looks like kids you saw flying the bombers in world war ii where theyd have the these troops outside. There would be 17s, b24s. You feel so intensely proud of these people. In the after we had completed the the t3 stain, nostay, i made one final trip to the training area, which is right in the corner of the room, because i wanted to thank all of your instructors for the job they did in getting us ready. I was concerned because the one before we started shift, i had gone in and kuze wasnt there. This time, he was in there and i found out that in his haste to get into Mission Control, the day of the Lunar Landing, my lead trainer had rolled his car. He had fortunately emerged unscathed and without Second Thought about the car. He continued to get a ride in here. And reported to his consul in Mission Control. Walking over to the press conference with doug, doug and i talked about the fact that not only had we landed on the moon but i almost felt cheated of the emotional content of that landing. Where everybody else was out celebrating. To this day, i just sit down there in Mission Control, you have to stay so intensely focused that other than just a very brief cheer, sort of a whoop from the team at the time of landing, and the and the realizing how close this thing was, we immediately had to get back to work. And it was i would have liked to have found some way to get some of the feelings, the emotions of the other people. I know chris and dr. Gillrith were behind us. It was a marvelous time. It was a time of pride within the nation. It was a time of turning young people loose, giving them their head, seeing what they can do. And for a very short period of time, i think we united not only our country but the world. And its marvelous what could be done by such an event. I just wish we could recreate it, do it again today. Perhaps at some time in the future, maybe on a mission to mars or something similar, there might be such a moment again. Do you think that might ever happen . I sure hope that my children and the youth of america can find this this kind of a dream that we were given my president kennedy because it was a dream we lived. We were so fortunate and proud to be americans and living and to be challenged by such a magnificent set of goals. I dont think anyone ever considered themselves overworked or underpaid. The pay was the job that we were doing. And it was a it was an unbelievable time. We were privileged and proud to be born and a part of that very violent decade, however