Reflections on Saturn All-Up Flight Testing: George Mueller

George Mueller, shortly after being named NASA Deputy Associate Administrator for Manned Space Flight, introduced the concept of "all-up testing" to the Saturn/Apollo program. Rather than traditional method of testing rockets, which called for a slow, methodical program, testing one stage before adding another live stage, "all-up" called for a rocket comprised entirely of live stages from the very first launch.

It may seem strange to present "reflections" on "all-up" from the man who proposed it, but he made a number of comments regarding the concept, both during and after the Apollo era.

The first two comments were made shortly after the decision was announced, in Congressional testimony.

This first quote is from testimony prepared by Mueller for the 1965 NASA Authorization, Hearings before the Committee on Science and Astronautics U. S. House of Representatives, Eighty-eighth Congress, Second Session on H. R. 9641 (Superseded by H. R. 10456), February 4, 5, 6, and 7, 1964 No. 1 Part 1, testifying on Thursday, February 6, 1964:

All-up testing philosophy—A major decision was made in 1963 to adopt the "all-up" testing concept as a basic approach to our flight verification test program. "All-up" testing means all flights will be scheduled with complete space vehicles using live stages and flight-type spacecraft.

I would like to discuss for a moment the philosophy behind "all-up" testing.

In any program the nature of the tests performed are dependent upon the technological know-how at the time tests are planned. In 1958 when the Saturn I booster was conceived, technology dictated that a gradual buildup of the test program was the most prudent approach. This is a step-by-step procedure which is shown on this chart:

all up test philosophy

Scan by Google. Reconstruction by heroicrelics.

First we clustered tanks to form the S-I booster stage of the Saturn I vehicle and we successfully launched four of these with dummy nose cones. The second phase of the program was to place a second stage on top of the tested booster with a dummy nose cone and thoroughly flight test the live second stage. This was the configuration of the fifth Saturn I (SA-5) successfully launched at the Kennedy Space Center on January 29, 1964. The final phase would be to launch a completely assembled launch vehicle and spacecraft in manned Earth-orbital flight. The line down through the middle of the chart can represent manned space flight plans up to fiscal year 1964. The events during the past year such as four successful S-I stage launches; successful ground tests of the liquid-hydrogen second stage for Saturn I; the successful launching of the Centaur with its hydrogen upper stage and the results of the Minuteman program (which used "all-up" testing), have brought us to the point where the technology and experience is such that we can now drop this step-by-step procedure.

There are several advantages to the "all-up" approach. It will permit us to land an American astronaut on the Moon, and return him safely to Earth, in accordance with our schedule even though we are operating this year on a reduced budget. It will permit us to capitalize on successful flights. It will also allow us to gather a very large amount of data early in the flight program and thereby provide much needed information to our design organizations. It is planned in the Saturn IB and Saturn V programs to launch a complete un-manned space vehicle on the first flight in an Earth orbital trajectory.

Mueller was back in front of Congress a month later, this time in front of Senate Committee on Aeronautical and Space Sciences (NASA authorization for fiscal year 1965: Hearings before the Committee on Aeronautical and Space Sciences, United States Senate, Eighty-eighth Congress, second session, on S. 2446, a bill to authorize appropriations to the National Aeronautics and Space Administration for research and development, construction of facilities, and administration operations, and for other purposes), testifying on Wednesday, March 4, 1964. Mueller discusses "all-up" in a question and answer session with Frank DiLuzio, staff director of the Senate Space Committee:


Mr. Di Luzio. One of the most significant changes, I believe, to the NASA philosophy, has been the introduction of this "all systems up" concept which I believe you are the sponsor of, or at least you have been given credit for, raises some question in the minds of the committee members as to what it means. What is your definition of "all systems up"?

Dr. Mueller. It is flying on each vehicle those systems that will eventually be used in landing on the moon. That does not mean that each vehicle has all of the systems involved that are going to be used in landing on the moon. But insofar as possible, there will be as many of them as is economically justified.

Mr. Di Luzio. In terms of programmatic performance and cost and time what does it mean to your agency?

Dr. Mueller. It has enabled us to design a program that is the most economic program. I cannot provide you with exact numbers, but it has saved us some four, five, six, seven launches in reaching a given point in the program. There is a tradeoff. There is some increased risk associated with delaying all of the elements at the same time. But there has been a considerable acceleration in terms of the time at which we could anticipate carrying out the Lunar landing itself.

Mr. Di Luzio. As I interpret it, you say that the agency feels very confident technically that it is not an unreasonable gamble. There is always a gamble but it is not an unreasonable gamble. You think the chances of such are rather substantial?

Dr. Mueller. On the contrary, the ballistic missiles program indicates it is a very good gamble. In fact, we have learned more once we adopted the all-up testing concept in ballistic missiles per flight than we did prior to that time. We feel it is a very good gamble and one that we should take.

Mr. Di Luzio. I notice in your presentation you talked about ordering 15 vehicles. You are asking that they all be funded this particular year. Is this because you have to place contracts to order these for the long leadtime required?

Dr. Mueller. There are long leadtime items involved that require us to purchase now for the first of the SATURN flights. Of course, once you have contracted for those flights in the timespan you are talking about, it will be necessary.

The topic of "all-up" inevitably was raised during various interviews. Here is an excerpt from an oral history in NASA's Johnson Space Center Oral History Project, conducted on August 27, 1998. He discusses how the first flight (SA-501, Apollo 4) worked "very well" but that problems were encountered on SA-502 (Apollo 6), the second Saturn V launch:

Bergen: You were the one responsible for deciding on the all-up testing procedure.

Mueller: Correct.

Bergen: Can you tell us a little bit about how you came to that decision?

Mueller: Oh, it was easy. You just looked at the schedule, and you could see that if you went through the test program that Marshall [Space Flight Center] had laid out for the launch vehicle, that you weren't going to be landing on the moon in the decade. I don't think that anyone really who had been involved in the program disagreed with that. I don't know that that time they were all that convinced that we they were going to be able to land on the moon in the decade.

Bergen: Did you convince Dr. von Braun and his associates that that was a good idea?

Mueller: That was an interesting move, I must say, and it was also necessary to convince Bob Gilruth and his associates that it was a reasonable idea, because they weren't used to doing that either. But Werner probably had the more vocal opposition.

It was easy. You laid out the program and then—well, we started with what we had, and then we spent some time working with the centers, because by now I had the program offices in place, or at least beginning to be in place, and so we laid out a schedule that made sense. Looking, from my experience in flying these things, it was clear that you're much more likely to have a failure on the second stage than you are on the first stage, because you spend more time on the first stage than you do on the second stage, and so on and on and on.

We were in production on these things, so we were bringing everything together as rapidly as we could and in a sequence that would get them all together at the same time. So it didn't make much sense to fly the first stage and then fly it with the second stage, or fly the second stage separately, which was also proposed, and so on. By the time you had to do all of the work necessary to fly a single stage by itself, you hadn't really done the work you needed to fly the whole stack. If you lost a vehicle, you were likely to lose it at any stage so you might as well go as far as you can and find out where the problems are. At least that was my philosophy at the time. Still is.

So we went around talking to the centers, and the first time through they looked askance, and said, "You couldn't possibly think of anything so silly." They didn't quite say it that way, but made it real clear. It turns out that Kurt [H.] Debus was a strong supporter of the idea as soon as he thought about it, because he'd seen the same things I had, things blowing up all over the place, and indiscriminately stage-wise. So we had a major meeting at Marshall when he had all of his troops together and we talked about it. I finally said, "Well, the only way I can see to get to the moon in this decade is through this program." Werner finally said, "Well, it's risky, but I agree. I support that idea."

I must say we had a precursor to that. We had an offsite where we had all of the center directors together, and we talked through the program and what the alternatives were so that everybody was on the same baseline at the time. But it was a decision that I did make, and it wasn't unanimous by any measure or means.

Bergen: Did you watch the Apollo 4, the first all-up test launch?

Mueller: Apollo 4?

Bergen: AS-501?

Mueller: Oh, yes. Yes, of course.

Bergen: What were you thinking? Were you a little anxious when you did that first test?

Mueller: Actually, I was deeply enough involved in the program so that at that time I was more interested in making sure that everything that I could think of, or anybody else could think of, was done so it was going to work right. Of course, it worked very well. The 505 [heroicrelics: apparent typo; actually referring to AS-502 or Apollo 6] didn't work quite so well.

Bergen: Can you tell us a little bit about that?

Mueller: It was a great learning experience. One of the things that our organization, the organization we had set up with the program offices and the technical groups supporting and so on, worked exceedingly well in terms of identifying the problems and curing them, and identifying them clearly enough so that we certainly knew what the problem was, because that's always a problem when you're dealing with things at a distance.

We produced the problem on the ground and made the corrections necessary, and then we went through the entire history of those two flights, to be sure there weren't other anomalies in them, in as much depth as I've ever seen programs reviewed, and on the basis of that we felt confident enough that this thing was going to fly, that we flew the next one to the moon.