I always think that system engineering is about the people who work together having really good communication. And it’s that kind of communication that does good system engineering, tools or not!
A little more on solid versus liquid. Solids could be shipped by rail. To say it another way, the diameter of the solids is set by rail shipment. The American rails were forced by the British, we brought the British rail system to the United States which was set by the width of the wheels on the cart and the cart’s width was set by the Roman chariots that used to be on the roads in England because they made grooves in the pavement. That set the diameter of the Shuttle. Roman chariots wheel width was set by two horses in front of it. So there are some who say that the diameter of the Shuttle rocket engine was designed by two horses’ asses.
I have concluded that spacecraft are not like airplanes.
The following is a transcript from the first lecture Engineering the Space Shuttle by MIT and edX, presented by Dale Myers.
The talk was made in 2005.
Links to the lectures:
- Origins of the Space Shuttle or The Making of a new Program
- Development of the Space Shuttle
- Bureaucratic Space War
- Political History of the Space Shuttle
- Space Shuttle Orbiter Subsystems
Mr. Dale Myers is, what you might say, a true aerospace engineer. He had a very distinguished career in both industry and government and aircraft and space. Dale, or Mr. Myers, was Deputy Administrator of NASA from October 1986 to 1989, and that’s when President Reagan called Dale Myers back to be Deputy Administrator after the Challenger accident. Mr. Myers was Corporate Vice President of Rockwell International, President of the North American Aircraft Group, where he was responsible for the B-1 and various military and commercial aircraft. 1970, he had been associated with Rockwell International, and Vice President and manager for the Apollo Command and Service module. So, he was Apollo and Shuttle.
The key thing that Mr. Myers is going to talk to you about today, he was the NASA Associate Administrator for manned space flight in 1970, when the Space Shuttle began. And Mr. Myers is going to talk to you about the beginning of the Space Shuttle and how the external environment helped create or generate requirements that really forced, you might say, the configuration of the Shuttle. I think it’s very important for you to understand that, because many times when you get out and go to work, the requirements become generated by external environments.
Introduction by Jeff Hoffman
Dale Myers played a critical role in the early phases of the Space Shuttle program.
I want to emphasize two critical messages from his lecture that I hope you’ll take away with you.
First, the influence of politics and budgets on technical decisions, and the willingness of many technically competent people to believe in what they could do with reusability, despite never having built and tested a reusable spaceship.
Second, the important part in his lecture regarding flight rates, is the clear relationship of flight rate to the value and cost of reusability. The more often you fly, the lower the cost of each flight and hence the greater the value of reusability.
As you’re going to hear many times during this course, a critical element in systems engineering is getting the requirements right, and Dale emphasizes the importance of requirements and discusses how the requirements for the Space Shuttle were developed. He emphasizes that requirement drivers were not just technical, but political, economic and military. From an astronaut’s point of view, I would say that the lack of a crew escape system was critical. The requirement placed on the Shuttle was that it would have enough redundancy to be able to return safely to a landing field even after multiple malfunctions. Well, as it turned out there were failures that went beyond the Shuttle’s capacity for safe return. Dale ends his talk with recommendations for the design of future spacecraft, which is extremely relevant for the systems engineering aspect of this course.
Two other important aspects of systems engineering are discussed in the lecture. First, Dale mentions the problem of accurate cost estimation. In Aaron Combs’ final lecture on systems engineering, he discusses in a lot more detail the problems of cost estimation. Second, in my comments following Dale’s lecture, I refer for the first time to the so-called iron triangle of systems engineering, the intimate relationship of cost, performance and schedule. You’re going to hear a lot about this iron triangle in future lectures, because it’s one of the basic principles of systems engineering.
Let’s go back now with Dale Myers to the early 1970s, when the very existence of the Space Shuttle was still a matter of debate, and we’ll hear from someone who played a critical role in determining what NASA had to do to make the Space Shuttle a reality.
The Making of a new Program
Thanks for the opportunity to talk to you guys about a very interesting historical element.
I was asked to talk about the origin of the Shuttle. And I was there in 1970. That’s one of the prettiest pictures I’ve ever seen of the Shuttle. That’s a picture of the additional photography that they brought into the system after the Columbia accident, and this was used on this last flight. First time I’d ever seen the rear view of all the connections for the transfer of fuel from the tank into the Shuttle, the connections to the tank, the forward bipod where the foam was that came off on the Columbia accident. Just a terrific picture of all the tiles up under the wing that Aaron was so involved with.
Here’s another one that’s really a first for me. This is the Mach-1.1 shock on the Shuttle about 20,000 feet altitude. That big envelope of condensation, not as pretty as it looks on a F-18 or some really slick airplane, but it’s there.
I’m going to talk about what happened leading up to the Shuttle and describe the specific interests and personalities of the people who are involved.
Jim Webb was the administrator of NASA from 1961 to 1968, and he was a terrific interactor with the rest of the administration and with the President directly, and did a great job of administering NASA through the Apollo program up through 1968. It turned out in 1968, things were kind of going sour for President Johnson, and Webb’s big tie was with President Johnson, and he ended up leaving in 1968 after he suggested to President Johnson that he might want to leave some time soon. He was probably thinking he was going to stay through the lunar landing, but Johnson said, “Why don’t you leave now?” I don’t really understand the interaction that was involved there.
Webb didn’t want to make future plans. He really never paid much attention to the work that was being done inside the system on new ideas, new things beyond Apollo. And of course, the Apollo was an immense program, 400,000 people, well, 300,000 on the Apollo, another 100,000 on other activities in NASA, like the Aeronautics Program and the Science Programs. But Webb didn’t want to talk about things that were going to happen beyond that time period.
In the meantime in the back rooms, a lot of people were doing a lot of thinking about where does NASA go after the Apollo program. Apollo, at that time that Webb was there, had planned to go through Apollo 20. It was going to go on until 1973 or so and Webb probably took the attitude that we don’t need to think about the future yet.
When he left in 1968, he brought in a fellow named Tom Paine, who had been at a General Electric company doing advanced planning for General Electric. Very bright, very aggressively forward-thinking guy. A guy that I always felt never saw a future plan he didn’t like. NASA was doing a fantastic amount of future planning at that time, because in the 1968 time period, we’d just done the Apollo 7, gotten it back into flight again. At the end of 68, we did Apollo 8, which went around the moon. NASA could do no wrong at that time, they were just on a step. With Tom coming in in early 69, all the work that was being done by NASA at that time, the idea was that the NASA programs were going to continue to grow and that you could really begin to do some expansive thinking about going out into space.
There had been work going on since 1964 on lifting bodies and on different configurations that people imagined could be used for traveling in space and returning to the ground in a more sophisticated manner than coming down on parachutes in the water. The water landings were extremely expensive, having a whole Navy out there to support them. People were beginning to think about land landing. By 1969 enough pressure came on the administration that Nixon appointed his Vice President Spiro Agnew to run a program reviewing the future of NASA. He got a really good group of people together.
He got Bob Seamans, who I’m sure you all know. Tom Paine, the administrator at NASA. Lee DuBridge had been head of Caltech and was the science advisor to the President. They had a guy that was the head of the Atomics Energy Commission and the head of the Bureau of the Budget.
They did about a six-month study, supported by NASA. NASA’s dreams were that there should be a space transportation system that would include the Moon and finally Mars. And it started with a 30 foot diameter 12-man space station, two of them in Earth orbit, possibly reaching 100 people in Earth orbit; another space station the same size around the Moon with 12 men; a lunar base; a nuclear stage to transfer data or resources from Earth Orbit Space Stations to the Lunar Orbit Space Station; a two-stage fully recoverable Shuttle with 100 to 150 flights a year, because of this massive program that was being developed; a Skylab with five visits by the command module.
This, by the way, was a second Skylab. Skylab was in our program and a second Skylab was under construction at that time, in this time period. And of course to do all of this we would continue the Saturn 1B and the Saturn V production. Those are the big rockets who are involved in the Apollo program. And a space tug to go to higher than low Earth orbit, to geosynchronous. And as I mentioned the nuclear stage and the Mars program on 1983.
Supported by NASA’s ideas
- 30 ft. Diameter, 12 man Space Station
- 2 in earth orbit, one in Lunar orbit
- Lunar Base
- Two stage fully recoverable Shuttle
- 100 – 150 flights per year
- SkyLab with 5 visits by Command Modules
- Continue Saturn 1b and Saturn V production
- Space tug for higher orbits than LEO
- Nuclear stage for Moon and Mars
- Mars program by 1983
That was all presented to this group, and they ended setting up three different programs. One was this massive all-inclusive program. The second one was a program where the Space Shuttle would be built, and the plans to go to Mars. I never found the report, so I don’t know exactly how they described that, but to go to Mars the NASA program said you had to have a space station to first develop medical information about man’s long duration in space. In other words, how long a guy could last in space to go out to Mars. And it became a fuel transfer operation where low Earth orbit rendezvous, and docking, and transfer of fuel would be made for a device to go on to Mars. That second case, the one of, “Build the Shuttle and go to Mars,” was the one that Agnew and Paine recommended. Paine, in his mind, said, “There’s gotta be a space station with that.” And so he left in place the studies that NASA had out with industry on building a space station.
NASA then started a program on a fully recoverable two-stage Shuttle. Been a lot of studies of how to do that and we’re going to get into some of the system dynamics that were involved in that program as we go along here. Meanwhile, the budget crashed. NASA had a budget of about $6 billion in 1968. And by 1970 it was down to about $3.7 billion. Actually, at the same time, the manned space flight budget had gone from about $3 billion down to $1.7 billion. So, it got hit even harder than the rest of NASA during this time period. The reasons, we were in the middle of the Vietnam War, the budget deficit was going up dramatically, President Johnson had started The Great Society program for the poor in the country and that was a big load on the budget, and Nixon just wasn’t a big supporter of the space program, and so the budget was going down. The question was, was there going to be a human space flight program at all? And that was a really big question, because in a time period about a year after this period one of the senators put a bill before the Senate to cancel the Shuttle.
The Shuttle Phase B Program was underway by that time. We did studies Phase A, a small amount of money to industry. Phase B was enough to get a definition to where you could decide that you were ready to go into detailed design, and Phase CD was actually the design and development and testing. We were into Phase B on the Shuttle at that time. He brought forward to the Senate, “Let’s cancel the Shuttle.” And the vote was 50-50. And so the Vice President had to go in and vote to keep the Shuttle program going. That’s how close to cancellation it was.
A really important guy in all of this is a guy named George Miller. He had been head of the Manned Space Flight Program. He had been the stimulus within NASA for this broad systems study of going out to lunar bases and then to Mars. And he left in 1969, late 69. He had done his job, he got man to the Moon and home safely, and he saw this cut in budgets was going on. I don’t know whether that really influenced him to leave, but I think his general pattern had been that whatever he wanted to do, he wanted to complete it successfully, and then he would move on, and he did that with the Apollo program, so he moved on. George was a guy that really supported this tremendous set of future dreams for NASA.
Tom Paine left in late 1970. The reason he left is he kept pushing for a space station and the people in the administration had seen the studies that had been done by this Space Task Group where Agnew had said, “Let’s do the Shuttle, and then let’s go to Mars.” Paine knowing in his view, that you had to have a space station to be able to go to Mars, kept pushing the space station, a 12-man space station that would require a Saturn V for launch. It was a big expense and it was a program that really called for NASA’s budget to go up instead of down. He accepted the idea that it had been pushed down to the $3.7 billion level but he expected it to be $6 billion or $8 billion by 1974, and nobody in the administration was buying that. So he left in 1970 and I think he was sort of asked to leave. I don’t know that for a fact but all the evidence would seem to be that he wasn’t really making it with the administration.
I think this turns out to be kind of an important part here. Because when Tom Paine left there was kind of a bad feeling, a bad taste in the administration about NASA being too aggressive and wanting more and more big programs.
Paine left in 1970, George Low became the acting administrator, and he became a very important part of the Shuttle system background. His background, by the way, started way early in NASA, and he had been the program manager for the command and service module for a period of time before he went up to NASA headquarters. And I guess, Aaron, you became the program manager after George left. I came in in January of 1970, I had been in charge of the command and service module at Rockwell and George Low asked me to come back. And I had worked so closely with George that I felt a kind of a commitment to help in that area. I went back in 1970.
Jim Fletcher came in in April of 1971. And we saw where we stood as far as the budget is concerned. In 1970 with this new cast of characters we kind of accepted the idea that we were in trouble to the place where we could lose manned space flight completely and our real strategy had to be to get something that would be important to the future of NASA with respect to the programs. And our view was that the most important part of the game was to build a Shuttle that would reduce the cost of getting into orbit. And that was the whole idea of the Shuttle. There was a general consensus that if you had a Shuttle that would be recoverable and reusable it would reduce the cost of the operations. As they used to say in those days, I think I have it on another chart, you wouldn’t think of flying from San Diego to Boston on an airplane and then throwing away the airplane which is of course what we were doing with the ballistic systems. But we thought if we could get a low-cost transportation system to a low Earth orbit, the rest of the systems would then follow naturally.
But because of the budget picture and because of where we stood with the Shuttle in Phase B, recognizing it was going to be an expensive program, things started to fall out of the program. They canceled the Apollo 18 and 19, I guess 20 had already been cancelled. We cancelled Saturn 1B and the Saturn V which were our big heavy-lift capabilities. Canceled the second Skylab that was already essentially complete. That’s the one that’s in the Smithsonian Museum in Washington. Cancelled the command and service modules. Cancelled the 30-foot diameter space stations, and that was a big hit against the group, because we were in Phase B there getting ready to go into detailed design on a 30-foot diameter space station. We didn’t start the space tug, we didn’t start the nuclear stage, and we deferred the Mars program. Industry went down from 400,000 people working for all of NASA programs, down to about 140,000, 150,000. I’ve seen numbers lower than that.
Concept for the Shuttle
Re-usability equals low cost. That was fundamental. Everybody believed that. We had studies done by all sorts of outside groups: IDA, the Aerospace Corporation, and others that did studies that essentially agreed with us that there would be a terrific reduction in the cost of getting stuff into orbit if we would build a recoverable vehicle. It was clear that since the R&D, RDT&E costs are higher, that you need a whole bunch of flights. In other words, if they had a few flights, the extra R&D on the Shuttle wouldn’t pay off because you could build cheap ballistic launch vehicles that would pay off before the Shuttle went, so you need a lot of flights for a recoverable vehicle to be economical. The lower the R&D, the less flights needed to be better than the ballistic launch vehicles. And if you got a lot of flights, because the flight costs are so low, then a two-stage fully recoverable system would be the right way to go; that was our concepts of what we were dealing with in the Shuttle.
There had been a lot of technology. The early lifting body was done by a guy named Burnelli. Burnelli was in Long Island, and he built a first lifting body.
That’s an airfoil section, and that’s a broad piece of fuselage, wide enough that the two engines could be involved in it, big windows for a transport. It was really quite an interesting beginning of a cargo airplane in 1921. He built one of them, and that was the end of that. But there were a lot of other things going on. After Sputnik, the United States just kind of went wild with ideas for a while and then settled down on having NASA put in place, decided that the military dinosaurs and more programs wouldn’t be done, that NASA would take over that kind of activity. But we got some really interesting stuff going: HL-10 lifting body, the X24A lifting body, the X-15, although that was not considered a space device, really did end up. By the time they put external tanks on it, it got up to Mach 6 and 300,000 feet, really some terrific performance out of that airplane.
And then I added the Navaho, which I worked on for many years, because it had a parallel tank separation at Mach 3. The booster was under the vehicle, the vehicle was a ramjet vehicle, and it separated the Mach 3 at about 40,000 feet, so it was a high-dynamic pressure separation. But it showed us a parallel separation would work, and that gets into this picture later.
Next step was in that 69-71 time period, there was a guy named Max Faget, who is a really important, almost a genius in my mind, in design, that did the original Mercury and Gemini capsules, physically designed the shape of the Apollo command module, and then came up with this first sort of practical view of a two-stage fully recoverable system. It had straight wings like an X-15. In fact, if you looked at the plan for them, it looked quite a lot like an X-15, but it had two of them. They had pilots in each of the two stages and had internal fuel. It had metal shingles, what I used to call unobtanium, but there was like molybdenum, and Rene 41, and some really interesting materials which were really difficult to handle, stress-corrosion problems and all kinds of things that were tough to handle, and that’s why I talked about unobtanium or some ablative.
Max expected to have to use ablative on the leading edge of the wings. It had varying payloads. The highest one I saw in any of the history was 20,000 pounds, but 14,000, 20,000, that kind of thing. A payload bay of about 12 x 40, and 400 miles max cross-range; this gets important in requirements. At that time, because we were going to have all these space stations and go to the moon and all this sort of stuff, we were going to have 100-150 flights a year, and if you have a lot of flights it overcomes the base cost of the RDT&E, and he was getting down into the $5 million a flight in his estimates. Meanwhile, because we had lost the space station, we had lost the lunar base, all this grand plan had disappeared, we needed more payloads; we needed to get up to the 40-50 payloads a year to be able to make the Shuttle look economic at the levels of cost effectiveness that the Office of Management and Budget was demanding of us.
After this vote in the Senate, George Low decided that we had to be responsive to the OMB, so we had to get some more flights, and this is where our requirements began to come into the picture. We spent about a year working with the military where they finally agreed they’d put all their payloads, and I mean all their payloads on the Shuttle, if we increased payload and designed for 1500 miles of crossrange, and met our cost/flight estimates.
The commercial people were eager to get on the Shuttle if our costs would be this low because they were beginning to see launch cost equal to or more than the cost of the satellites that they were putting up (assumed we would develop a low cost upper stage and meet cost/flight estimates).
And the science people bought into the idea of space servicing and a low cost reusable platform. This really got important because they agreed to design the Hubble Space Telescope so that it could be serviced in space and that turned out to be, of course, the key to the Hubble because of the mistake that was made in the mirror. The re-servicing of the Hubble Space Telescope is what, by bringing another optics in front of this distorted mirror, brought the Hubble back to the fantastic performance that it has today. The science community, as they thought it through, they could see that they could later chain sensors and add additional stuff. The head of the science group enthusiastically supported it and got the system out there to support that idea. They worked very closely with us on how to design it so that you could get access to the thing in space with all the difficulty we have with gloves and so on. They worked to help us understand how to remove and replace systems, and so they did.
Because of the military requirements we had to change our specifications. This became another one of the elements that drove the final design. The military wanted a 60-foot long payload bay, it had been 40 in the designs that we had been doing so far, they wanted 40,000 pounds Polar Orbit, and that made our due east payload up to about 65,000. That was a big change from 20,000 to 65,000. They needed 1,500 miles crossrange. They wanted to be able to go around the Earth, while the Earth turned, and land at the same spot, so they had to have 1,500 miles of crossrange. You could do it a lot of different ways. You could carry turbojets, and you came back in and fly it back to the 1,500 miles, or you could do it without turbojets, which means you have to have air dynamic crossrange while you’re coming in.
The payload bay increased to 15 ft. x 60 ft. 15 was an increase by NASA because they saw that they didn’t have a Saturn V anymore to do the space station, so the best they could do is increase the diameter in the Shuttle to where they had a 15 foot diameter to where they could carry the sections of the space station that we now have in our program. We thought anything less than that was just too cramped for the guys. We decided we would find a non-ablative reusable thermal protection system; technology had moved far enough by that time that we were beginning to see these ceramic tiles developed to the place where they looked feasible. They had been able to find a hardening for the surface that made them less penetratable than they had been, and carbon-carbon came in that we could use for a leading edge for 3,000 degree leading edge temperatures.
We followed the tradition that said, “If it’s fully recoverable, it’s going to be cheaper, so let’s go for a two-stage fully recoverable system,” and with all the other things that we were developing at that time to reduce the cost of operations with automatic check-out and so on.
I wasn’t able to get that slide down far enough to show where the Saturn V was, but Saturn V is only about 50% longer than the upper stage there. So this thing had gotten big. The booster was larger than a 747, had to operate up to about Mach 6. The orbiter was about the size of a MD80, MD90, the twin engine small transport. They were big, and these things had 12 big high-pressure engines in them. We in management and I think the guys in design were getting pretty worried about whether an airplane that large at that Mach number was going to be a practical thing in terms of a system.
That’s not a system engineering approach, that’s sort of a gut feeling that you get after being in the airplane business for a lot of years and watching the development problems that were involved on the X-15, for example. How long it took the X-15 to get to where it could go to Mach 6. But that was the direction we were going.
By the way, one of the companies had the wings on the orbiter turned up. I don’t know why but they had them turned up.
The reason you see two different configurations here is in our Phase B studies in the industry we said, design us one that only has 400 miles crossrange, and design us one that has 1,500 miles crossrange. The upper ones had 1,500 miles cross-range. The delta wing will do that, the straight wings won’t. As we developed these requirements it became clear that we were not going to go with a straight-wing system.
These Phase B studies that we had showed that we were going to have a development cost of two stage fully recoverable Shuttle would be between $12 billion and $15 billion for R&D. And about that time, Nixon had a meeting with Fletcher and said, “You can build any kind of Shuttle you want as long it’ll only cost $5 billion dollars.” Well, that was a big shock to the system. And OMB (Office of Management and Budget) having heard that said, “Make it cost-effective.” And that was a real tremendous driver in the system because we had never been asked to do that before and we had a whole new set of requirements to try to deal with.
We’d had this Phase B program, it was almost complete, it had all these big beautiful configuration studies, and we had to look again. So we went out and said, “Let’s get imaginative, guys. Let’s see if there’s any way that we can reduce the cost.” There’d been enough going on where one of the companies had been looking at the possibility of putting external tanks, like drop tanks, on the top of the wing on each side. There were two of them, one on each side of the orbiter. And it made the orbiter itself, of course, much smaller. Remember, we’re carrying hydrogen and oxygen, and we were doing it inside the vehicles in those studies you saw in the Phase B, and so it grew the outside dimensions tremendously. And by going external with the fuels it really shrank down the system to where the diameter of the payload compartment was essentially the diameter of the orbiter. People began to look at other ways to do it. We had guys coming in and talking about single-staged orbit and that was one that I rejected without study because I knew that the mass fractions required for that were just out of the world of reality.
There was a thing called a TRIMESE, where the theory was that you had three vehicles: two of them were deltas, they fit together in a nice little teepee and would be used for boosters going up and the third one would go on into orbit. And that was kind of a dumb idea because it turns out boosters and orbiters have entirely different requirements and so they might look the same on paper but they would not be the same when you build them.
Lockheed came in with an X-24B which had tanks mounted up forward of the delta wing and the idea would be that they would peel off after fuel was fed to the main engines in the orbiter itself. And then we began to see these external orbiter tank studies. When the tanks began to look good externally then the question is, do you boost from under the tank or do you boost with two boosters parallel to the tank itself? When the tanks went external it finally ended up obvious that you’d want one tank instead of two, so that one tank went underneath the orbiter. Then the question is, do you boost through the tank or do you boost in parallel to the tank with two attached boosters?
We had all these different studies and what was happening in the administration was they were kind of locked up with reducing manned space flight budget down to like $1.5 billion to $1.7 billion. We needed to do this cost-effectiveness study for OMB. We hired an outfit called Mathematica which had a senior well-known economist named Morgenstern and a bright young guy named Klaus Heiss who did a study for us on the cost-effectiveness of the Shuttle. To make a very long story short, the results were that the present configuration that we have for the Shuttle today is the one that looked the best. The present configuration being an orbiter with a tank under it with the hydrogen and oxygen in that tank fed separately into the orbiter and to the main engines which were so expensive that we wanted to recover them and boosters being solid rockets attached to the tank so that the total vehicle was a little shorter. And important point: at that time the solids were recoverable. Their wall thickness was enough that you could use the solid rockets, drop them off by parachute into the ocean, pick them up, bring them back, clean them out, and use them again. And that was going to be a cost saving in the program.
By doing all this, we had lift-off thrust augmentation of the engines of the orbiter. These engines were 12,000 pounds per square inch internal pressure engines, staged combustion, the most advanced technology you could imagine, and they were started a year before the Shuttle was started to give them more time to develop. They almost became the long pull of the 10, but I think maybe, when it finally boiled down, the thermal protection was the longest pull. He was down there trying to fix them. I think he was almost down there gluing them on, but, down at the Cape, when we were getting ready to launch, we were still having trouble getting the thermal protection system working right.
A lot of other things that happened at the time. In 1971 the supersonic transport was cancelled and that was a big technology blow to this country. There was a major program that would have absorbed a lot of the high-tech engineers that were involved in the Apollo program and I think some of the administration thought the supersonic transports a better place to have our technology capability than would be space shuttle. The supersonic transport was cancelled by Boeing and I think that probably helped the atmosphere that was involved.
The other thing that happened is the Congress and the administration finally got the idea that we really weren’t going to build a space station immediately, that we were just interested in getting the Shuttle started, and so we didn’t have this massive budget increase that Tom Paine wanted. And Fletcher kept working on trying to get budget spread so that it wouldn’t be a major peak in budgets close in. He did that by starting a main engine early, starting the tanks late, starting with solids late, and putting obvious emphasis on the orbiter itself. That spread the budget out and helped a lot in giving the administration the feeling that we weren’t going to kill them with budget requirements.
Nixon started the program on January 5 1972. George Low and Jim Fletcher went over and had about a 40 minute talk with The President Nixon and he announced the same day that we are going to start building the shuttle. It’s going to be a reusable orbiter and engines, reusable solid cases, expendable fuel tank, 40 to 50 flights a year, 10 to 15 million dollars per flight in 1970$. Our internal calculations worked more like 10 million but we wanted to have some pad in it. And 5.2 billion (1970’s) dollars plus a 20% reserve for the administrator (R&D) for what we call unknos, unknown unknowns, the things you get into trouble during a development program where you need some more money to do some more testing.
Nixon agreed to that, the Bureau of the Budget (OMB) was in the meeting with him, and as soon as Nixon left office, Office of Management Budget (OMB) forgot the 20% reserve. So there was now 5.2 billion dollars in 1970 dollars. To make it worse, the NASA Comptroller, pressed I’m sure by OMB, didn’t agree that we would use 1970 as the base. He took the 5.2 billion dollars in 1972. We lost two years to inflation. It may sound like not a to you but it was a lot to the guys working on the program because it was clear that we were going to have a tough time meeting that budget.
Here I am, explaining to the press. I think that was about two days after Nixon’s announcement. One of the studies was to use the first stage of the Saturn V, the S-1C. This one is the winged version. There are all the engines in the back here. In this design we were using the first stage of Saturn V boosting directly into the tank which was attached to the orbiter. The other one was parallel, that was liquid. They look like they’re bigger diameter than the orbiter. A lot of people were just pushing a pressure-fed liquid engine, so it should be sure you had the capability to cut them off, and the idea was, because they were pressure fed, the thickness of the walls was enough that they too could be recovered in the ocean and brought back. Final decision by the people that were in the propulsion business in NASA was that the technology looked tough. It was new, we didn’t have a background of pressure-fed boosters, and the solids looked like they were a better deal.
Design issues as I saw them as a head of Man Space flight where that the Delta Wing was required for crossrange, the external tanks were much lighter, the system got to about half the weight because of all the reduction in external configuration when you took all the fuel out and put it separately in the tank, and thermal insulation – we bought off on the ceramic tiles, carbon-carbon insulation and fiber blankets, same as we have today. Solid or liquid boosters – solids looked more reliable at that time and cheaper R&D. There had been a history of solids on many of the large military boosters and they looked better. At that time I thought that we were going to have a way to terminate the thrust of the solids. Engine location and type started on the ground for safer, better performance, and the stage combustion for the better performance. We had studied retractable turbojets. Once you got into the atmosphere, you pop these turbojets out and flew home. And we decided we couldn’t handle it, thank God. We had all this lifting body experience where the guys that landed these very low L/D (L over D) devices and actually the orbiter had a little better L/D than some of the HL10s and X24s. So we dropped turbojets out of the system. Series versus parallel boosters – series was heavier and had less performance, a lot more bending loads in the system. When we go up, we go max Q and with cross winds we get big loads on that wing, and so this turned out to be a heavier way to do it.
A little more on solid versus liquid. Solids could be shipped by rail. To say it another way, the diameter of the solids is set by rail shipment. The American rails were forced by the British, we brought the British rail system to the United States which was set by the width of the wheels on the cart and the cart’s width was set by the Roman chariots that used to be on the roads in England because they made grooves in the pavement. That set the diameter of the Shuttle. Roman chariots wheel width was set by two horses in front of it. So there are some who say that the diameter of the Shuttle rocket engine was designed by two horses’ asses. Those are the guys who wanted to use liquid.
Solids could be shipped by rail, they had better reliability record at the time, they could be recovered, industry studied pressure fed to recover them, designers thought they could turn off solids but later they found they could not turn them off uniformly – the thrust variance that would be between the two would be totally beyond capability of the vehicle to sustain it. So we dropped it.
Thermal insulation was also a new development that had been experimentally tested. Ceramic tiles, carbon-carbon, and external insulation blankets – all looked like they were going to work but we had a lot of work to do and the ceramic tiles really turned out to be one of the toughest new technologies that we got into.
High pressure staged combustion engine was a big new development and so that was started early.
Design of the crew escape – the idea was we’re going to be able to terminate the thrust on the rocket engines. We looked at these rockets to pull away the cabin and none of them had a broad application. You had the question of safety. If you took the whole front end of the vehicle at the launch site that raised big questions of the reliability of the system. We went through a lot of studies to try to find a way to capture the crew in case of a problem and never found a system that fit into the program. We ended with crew escape only with a complete structure and that of course was the problem with Challenger where we ended up wrecking structure to where we did not have a recovery capability. But we put in a system where, if the vehicle were complete and structurally sound and was gliding, the guys could get out. But that’s the only escape system that we have.
I wanted to touch operation costs a little bit. We had built enormous confidence from the Apollo program. In spite of the Apollo 13 problem the rest of the vehicles worked beautifully. I used to say that every flight always had man in the loop some place during the flight that was important to the success of the program. Many times it was a minor thing like when Apollo 12 got struck by lightning when it was launched, the guys were able to reconfigure switches to get the power back on and get everything back to normal and it had a nice flight to the moon. Alan Shepard launched on Apollo 14 hit a few golf balls.
Every flight had man involved and every flight was a tremendous success except Apollo 13 which was launched in April 1970 and that gave us enormous confidence and we thought that we had tremendous support from the industry and the public.
We still were concerned about the operational cost, so we hired American Airlines for one to work with us on what the cost would be and how would you design the system to give you the least operational cost. The military, because they were committing to put their payloads on the Shuttle, had studies done by the Aerospace Corporation about the operational cost. There was a study done by IDA (Institute of Defense Analysis).
All three of them agreed that we were going to have tremendous reductions in the cost of operations. They didn’t quite come down to the same level that NASA had estimated but they were close. It was interesting that we all thought it could be done, we all thought there would be enormous reductions in the cost of operations with the Shuttle. We thought we had enough space-based hardware that we could do quick turn-arounds and handle it more like an airplane.
But NASA and these groups didn’t really properly account for the costs associated with post flight maintenance of the rocket engine. When IDA and the Aerospace Corporation did their studies we told them that the rocket engine is going to be reusable for at least 20 flights. It turned out it wasn’t. It was such an enormous new development that in the early flights of the Shuttle it took a lot of time and a lot of effort to replace and refurbish engines. Costs with assuring safety of flight in a hostile environment, and space is hostile. We’re dealing here with what amounts to a short amount of R&D, development testing, when you get into these flights. Costs with difficult cutting edge technologies, both engine and thermal program. The tiles worked, but often there were chips out of the tiles, so we had to replace tiles between flights. Costs with FO/FO/FS – this is fail operation, fail operation, fail safe. The airplanes have fail operation/fail safe. They took the attitude that if you had three computers that was plenty and if one went bad during check out you launched anyway. You don’t know that but that’s what’s happening to you on commercial airplanes today. We went one more: fail operation/fail operation/fail safe. We have four computers in the Shuttle and we can’t fly it without all four in perfect condition. So those things add costs when you do that. And then cost tradeoffs between R&D and operations. People have argued with me many times that our decision to put the tank externally was a bad deal. It turns out that it was certainly a bad deal on Columbia. The foam on that tank came off and hit the carbon-carbon leading edge of the wing, broke a hole in it and caused thermal excesses in re-entry. So you could argue, yeah we should have had a two-stage fully recoverable system. But those were the cost trade-offs in getting a system that would be accepted and bought off by the administration.
Operation costs have been the big miss that we made in this program, they have never got down to what it should have been. They never got down for a couple of reasons. We were never able to get to a flight rate that would favor a reusable vehicle.
We got up to nine flights back in 1985, the year before the Challenger disaster. We were not far enough to offset the research and development costs and to get the operational costs down low. The following chart is an interesting little summary. It’s not an exact thing at all but it gives you a feeling for what I have seen out of this program.
In 1970, $10M/flight price was based on same accounting system used for Apollo-hands on only, with a separate account for overhead.
With $400M/year overhead, and inflation according to the consumers’ price index, cost per flight would be:
|40 flights/year, no overhead||$10M||$23M||$50M|
|40 flights/year, include overhead||$20M||$45M||$101M|
|8 flights/year, include overhead||$60M||$135M||$302M|
In the Cape Canaveral we had a lot of other things going on besides Apollo, and we had the common support activities like the medical department in the male system as a common separate account, and all the costs for the Apollo were those that we called hands-on, things associated with buying parts, bringing in spares, putting on spares, checking out the vehicle and launching it. We had two different pieces of money involved in the Apollo program and one of them never was charged to the Apollo program. We uses that same accounting system for the shuttle as we used for the Apollo. It turned out that these separate items were a pretty big chunk of money, and I’ve assumed that it was about 400 million dollars a year.
Remember we said we’d do this job using 1970 dollars and we said that the cost would be 10 million dollars in 1970 dollars. 400 million dollars overhead with inflation, according to the consumer price index, 40 fights a year with no overhead or like Apollo a 10 million price in 1970 would be 23 million in 1981 and would be 50 million in 2005.
Same 40 flights, but including overhead would make a flight cost 20 million in 1970, 45 in 1981, and 101 per flight in 2005. Huge increase in price because of the inflation that occurred in the 1980-1982 time period.
8 flights per year, including overhead, runs it up to 60 million in 1970 dollars, and eight flights per year is what we’ve been running out recently.
Now, the cost per flight on the shuttle I don’t know, I know that it’s up in that 400 or 500 million dollar price. I use this only to give you a kind of a rough feeling that although we missed operational costs badly, we didn’t really just be totally out of them.
- The Shuttle has done everything it was designed to do. It has delivered Military, commercial, and scientific payloads to LEO and GEO, retrieved and replaced satellites, repaired spacecraft, and launched elements of the Space Station
- In the 80’s, shuttle had 4% of launches, 41% of mass launched
- Shuttle R&D was within what Nixon and Fletcher agreed. ($5.2B + 20% reserve in 1970$)
- Missed two key design issues (cold O rings and foam shedding)
- Missed operations costs. A two stage reusable system would have missed worse. Spacecraft are not “like an airplane”.
General shuttle performance was great, it did everything it was designed to do and probably a few more things we didn’t think of at the time. It has put military devices in orbit, commercial devices in orbit, scientific payloads all the LEO with solids, it has taken us to the geosynchronous orbits, it’s retrieved and replaced satellites, it’s retrieved satellites and brought them down to the ground to repair them, brought them back into orbit, it’s repaired satellites in orbit, and it’s launched elements to the Space Station.
In the 1980s, the Shuttle had only 4% of all the launches in the country, but it carried 41% of the mass launched.
Shuttle R&D was well within what Nixon and Fletcher agreed to, the 5.2 billion plus 20% in 1970s dollars. Probably only about five to ten percent of that was actually used. In that sense, they overran what the OMB said we were to develop it for, where they didn’t give us the 20% reserve. We overran it by five or ten percent.
We missed two key design issues: foam system engineering issues and cold O rings. In Challenger we had O rings which when they were cold, they lost their flexibility, and when they were cold in a design that was opened a little bit when the pressure came on internally – that was a disaster waiting to happen. That was a bad design. The way the O rings were designed into the vehicle was bad.
Second one is the foam shedding. We knew that we were going to have ice and/or foam on that tank, and we really pressed the industry to make sure that that foam was going to stay on. We had enough foam that we didn’t get a lot of icing, but we had that foam to stay on. We didn’t think so much of the carbon-carbon as the tiles, these brittle tiles that we had on the bottom of the shuttle. Foam shedding was known to be a problem all the way through development, but just has not been able to be solved. And after the Columbia accident, Martin Company, I assume, worked for two years trying to make that foam stick better, and it did stick better, but pieces still came off. So, fleet has been grounded and they got to get that fixed.
And of course, we missed the operations costs. Two stage reusable vehicle would have missed worse. I’m sure of that because of the size of that first stage booster and the lock numbers it had to go to.
I have concluded that spacecraft are not like airplanes. Every flight is a structural dive demonstration. You know, you develop an airplane and you fly it many times before you fly it to the corner the VG diagram, which explains where your aircraft can be damaged and example of which is shown below.
I can only think of only one exception. A guy named George Welch, one of the greatest test pilots North America ever had, flew the first fight of the F86 which was the fancy new jet that we brought in just before the Korean War, and on its first flight it flew so well that he took it in to a little dive and the Mach meter went up to one, and actually the ground data showed that he probably went to 1.04. Some say they heard a sonic boom. I’m not sure of that. But that was about a month before the X-1 went supersonic.
Test pilots in those days were kind of innovative and they did things that they were told not to do, but he did it.
Every space flight is a structural dive demonstration. We go right up to max q every time we fly (the point when an aerospace vehicle’s atmospheric flight reaches maximum dynamic pressure), we go through wind shears to take it up to high G’s, we go to high G’s on the way up, we go to high G’s on the way down, we go max thermal every flight. We’re dealing with a tough set of activities when we do this.
No reusable space system gets millions of hours of stressed operation that airplane gets. Once an airplane gets through development it starts getting millions of hours of test data or information where if you have a problem, you fix it. And you just don’t get that in these systems.
No reusable space system develops decades of evolutionary model improvement. The airplane business has been so dramatically economical that you could build new airplanes every 10 years or so and each new airplane took advantage of all the things known from the past airplanes and designed into it.
And as I said, every reusable system is exposed to enormous environmental variations every time: thermal, vibration, pressure, Mach Number. All these things happen every time.
And so I look at the Shuttle as being an amazing piece of machinery which has done extremely well in what I consider a continuing R&D environment. We just don’t have yet an operational system.
So, for the next program
- Keep it simple.
- Don’t stretch the technology
- Use good margins of safety
- Keep it as small as possible
- Carry as few passengers as possible
- Carry people or cargo, not both
- Keep requirements to a minimum
- Use as many past components and systems as have been proven reliable
- Design for operations
- Easy access, one man can replace boxes, etc.
- Keep a program design reserve to reduce Ops. costs
My view of the next program: keep it simple. It’s sort of been a prime view that I’ve had of design ever since I’ve been in the airplane business.
Don’t stretch the technology. Use really good margins of safety, because we’re dealing here with maximum conditions on every flight. Better play it safe.
Keep it small. Carry as few passengers as possible; carry people or cargo but not both; keep the requirements to a minimum.
Use as many past components and systems as have been proven to be reliable.
Design for operations. Very important! Design for operations. Easy access, one man can replace a black box where you do not need to run a big pick-up machine to take something out of it. And keep the design reserve while you’re designing it so that when operational issues come up you can design for the operational issues. And keep reducing the cost of operations.
If we had had it to do over again, it would have been great to be able to contain the requirements within NASA, probably build a much smaller system that you could get many more test flights at lower cost, but we didn’t have that opportunity.
We have the Shuttle disappearing into the distance. Decision had been made that the Shuttle be phased out in 2010.
It’s going to be a tough issue because now the Shuttle is down in between flights. Because we lost foam on the last flight they grounded the fleet so we can figure out what to do about that foam problem.
And then the hurricane Katrina knocked off the top of the VAB (Vehicle Assembly Building), which isn’t a big deal, but it really messed up some of the tank facilities and tank access, and people’s lives have been affected with losses of homes, and so there’s a whole bunch of new issues involved in the Shuttle that I read in the paper this morning, may mean another delay in the next launch of the Shuttle and that means a compression of the time between now and 2010, when they’re trying to use the Shuttle to meet the commitments that we have with the Europeans and the Japanese about putting pieces of space station up in the space. So, an interesting new problem for the shallow.
What went into the design of the shuttle and I think what Dale alluded to at the end is very much to the point and we all will be talking about this later when we describe individual systems. We have gotten out of the shuttle good performance despite the fact that we have had two catastrophic accidents which happened because of the design but also because of the way we operated the shuttle.
Had we not made the decision to launch Challenger on that cold day, who knows what would have happened? Similarly, we accepted the fact that foam was continually falling off of the tank even though that was incompatible with the design specifications on the thermal insulation for the shuttle. So we had basically two parts of the shuttle system, and we had design incompatibilities, but we chose to keep on flying.
But as a whole, the shuttle has been remarkably successful from the technical point of view. What we have been able to do in near earth space, compared to what you could do working out of an Apollo capsule, was absolutely phenomenal. And in fact, in terms of near earth operations the shuttle will be sorely missed when we retire it and there will be a lot of capabilities that we will be giving up. But on the other hand, where we really got it wrong by orders of magnitude was in the cost and re-usability of the shuttle. Perhaps that goes back to the requirements because again, we were trying to do an awful lot of things for the very first time, and yet we were being told by the Office of Management and Budget that it had to be cost-effective. In a sense, NASA was being asked to operate the shuttle almost as a commercial enterprise and to make money on it. This is like you build a test vehicle for the first time and you’re being asked at the same time to operate it at a profit.
And as you know, one of the systems engineering principles is you have this triangle: performance, cost, schedule – and you can’t specify all three. They are not all independent parameters. If you specify the performance, and then you’re limiting the cost, you can’t control the schedule. All three of those we in a sense got specified when we accepted the requirements to build the shuttle and something has to give, and in the end it was the schedule and the cost.
Q. I was intrigued by the different phases of development. You called these phase A, phase B, C and D. In those phases, when did you develop the high-level requirements, when did you develop low-level requirements, how much industry was involved in different levels, what percent was industry engineers, and what percent was NASA engineers?
A. The theory is that you do phase A as conceptual activity, and when you’ve gotten your requirements nailed down you then do a phase B. And that’s what we thought we had done. It turned out that the military requirements came in after phase B had been started, so we actually had to change the contracts with the industry to take into consideration those military requirements and they were a big change to the requirements. In that sense we had some inefficiency in the phase B and it was after we began to get the results of phase B that we realized that we didn’t have a system that was going to sell, that was going to meet the requirements. Instead of canceling phase B we finished the phase B because we needed that basic understanding of all of the systems and all the elements that made up the system. We finished phase B, but we started some additional phase A’s conceptual activities to try to find a solution. We had phase B extension to bring new configuration. By the time we finished that phase B extension we had all the requirements in place, we had all of the design understood well enough to start phases C and D. It’s pretty amazing that a device that was going to do what we wanted to do with the shuttle, to go into orbit and come back and land, the configuration really stayed the same from that point on. It’s just amazing that we did that well in definition, so that when we really started the C and D phase, which is the detailed design, things stayed in place. And that meant all the aerodynamic work have been done which is by the way the most wind tunnel testing ever done on a new system because we were working through the whole MAC number range, and all of the other elemental testing that was going on allowed us to keep the configuration identical from that point on.
Q. There’s been a lot of talk but seems obvious now in hindsight that the capsule of the orbiter should be on the top of the launcher to clear it from debris from a fuel tank or what else. At the time in the early stages was there ever any talk about safety issues and putting in orbiter so low on the wall?
A. Yeah, there was a lot of talk with Martin about foam shedding at that time. During the initial decision process for putting it on the side we had done the studies of stacking it in series and it was a weight problem. It was literally an issue of the structural weight of the orbiter mounted vertically because of terrific loads that you get separately on that system and so we recognized that the side-mounted tank was going to be a much more economical system. So we had to worry about ice and foam. And so we had a lot of discussion with Martin Company at that time. We did a lot of work done at Marshall too.
The key point to make is the following, is that should we have challenged the requirements? Making the orbiter so big with the payload bay so big, it was very difficult to put that on top. If you made it smaller, you could. The real question, should NASA, once OMB and the White House gave a cost constraint, and once we had the change in the Air Force requirements, should NASA head said: No, we don’t want to do it?
And that is a very fundamental issue in terms of understanding your requirements because the requirements drove the 14-day turnaround time, the fact that you wanted large payloads, that you wanted to get to the payloads, put the orbiter where it was. The fact that you needed a high performance engine and a lot of payload in orbit, said that you needed liquid oxygen/liquid hydrogen engine to get the specific impulse and the engine performance. All that added together with thermal protection system was basically a glass house which was incompatible with material coming off the tank. There was some you might say incompatibilities in the requirements and the question is, should we have challenged those requirements more strongly? That’s the very fundamental question. I don’t think we should have, but let me ask Dale what you would have done with the orbiter.
I did. I challenged the requirements inside NASA. I never challenged it with the military. I challenged them inside NASA with George Low and with Jim Fletcher and their conclusion was that we would not have a manned spaceflight program if we challenged the military requirements. And the rest of it followed.
It’s a very key question in today’s environment, because you’re infinitely smarter after it happens.
Q. Do we have better systems engineering tools now than we did in seventies?
A. Systems engineering is better. Cost estimation – I’m not so sure. We had the best guys in the country doing cost estimations on the shuttle but we missed it probably as much as anything else by just not having those people understand the complexities of operating in space. A lot more is known generally now about the cost of operating the space. The next attempt at a reduction in cost for getting into space will be a much more significant activity. I consider cost estimation to be a part of system engineering. A lot of it is much better, some of it is not.
When we designed the orbiter we didn’t have CAD/CAM systems. If you look at the Aft of the orbiter, it’s the hardest thing you’ve ever seen because we didn’t have a computer aided design.
If we had had that, we probably would have done a much easier job in the Aft of the orbiter and in the Midfuselage and in the Cockpit. And that is systems engineering. So, you today have much more valuable tools than we had in the Apollo program and during the shuttle program, but there still is a lot of education you need in systems engineering where you need to have a very good understanding of the Iron Triangle principles: the cost, schedule, and performance. And that is a continually evolving work in the systems engineering.
And I always think that system engineering is about the people who work together having really good communication. And it’s that kind of communication that does good system engineering, tools or not!
Q. Could you talk about the astronautic office and what they thought during those conversations, were they in favor of the recoverable fully piloted booster and what were their input on the risk?
A. They were aware of it. We kept in touch with the astronauts all the way through the development program, including the decisions not to have a launch abort system, and they all recognized there was risk in the program. No question about it.
Astronauts we involved, they were part of the design and development team and the requirements team, so they were very much in favor of it. Of course, the big issue, which we’ll talk more about, was escape system. We’ll go into that a little bit, why don’t we have an escape system. When Chris Craft comes you can ask him a lot of questions about that. The astronauts were very much a part of the design, the development, and the requirements of this phase of the program.
They weren’t too much in favor of an automatic landing a system.
Q. If I understood well, the initial goal for the shuttle was low cost of access to space. When did it become clear that the space shuttle will not be a low cost solution? Was it already too late to change the program requirements?
A. The problem was that we never got up to flight rate. There were payloads waiting for us, but we never got to fight rate. If we had gotten to a higher flight rate, the operational costs would have been lower. Not enough lower, because no matter what we would do, we never would have met our original estimates on operational costs, but as you saw by that inflation story that I had, cost today would be enormously higher than that 10 million estimate that we had in 1970, just because of inflation. But we never got flight rate, so we didn’t ever get to the lower cost. In the early days there was a lot of pressure to get that flight rate up so that the cost per flight would come down and that pressure got to be instilled into the people in NASA and in the industry to where the decision made on that cold day in January, or whatever it was, on the Challenger, even though there was evidence that those O-rings had leaked in previous fights, the decision was made to launch. That’s a management/policy issue associated with trying to reduce the cost of flight. So that was a bad decision.
One other thing on cost per flight, you have to realize when you’re dealing with the reusable system it’s hard to specify exactly what you even mean by the cost per flight. You can take the total amount of money you spend on the shuttle program every year and divide that by the number of flights. For this year we only had one flight, and of course it gave a pretty high cost and last year the cost was infinite. On the other hand, you can you can look at what’s the cost of having six flights a year versus what’s the cost of having seven flights a year and that’s what you would call an economics of the incremental cost of a flight. Also, you have to realize that in the cost of a flight there’s an awful lot of things that were wrapped up, not just the cost of the shuttle itself, but all of the mission operations, the flight planning that has to be carried out. There was one flight, it was a space lab flight back in the 80s, where they launched the Space Lab mission. It was supposed to be a two-week mission but they had a fuel cell problem, so they had to come back after four days, and in order to get the scientists the opportunity to get their flight data they rescheduled the flight for a few months later. So they had the same crew, they had the same flight plan. They didn’t have all of the expenses, the paperwork expenses, the training, all of the re-planning, the experiments were the same. It was the least expensive flight that we possibly could have run and at the time the estimates were that that actually cost NASA probably about 120 million dollars. That was kind of the bare bones estimate of the incremental cost of the shuttle flight. And then it can go from there all the way up to billions of dollars if you just take one flight a year like we had this year.
The other thought too, I remember going to see Dale Myers when he was Associate Administrator for a space flight and I was the orbiter project manager. As he pointed out, we had four computers. The original thought was that if one computer went out on the ground we had lift-off with three computers, and that’s what we talked about. But of course, that never happened. Not only that, we now have five computers. We actually have the fifth computer which acts as a back-up. Things change, environments change. And we were going to do very routine payloads, we were going to take up, launch a payload and come back down. Just very routine payloads. Almost every payload today is different and it does take that large amount of infrastructure to get there.
One of the cost elements in our cost-effectiveness study was a reduction in the cost of scientific payloads because we were going to have a sort of a boiler plate bus, heavy rugged bus that had power and communications. And the scientists would bring their experiments to this bus, put it on this standard vehicle, take it into orbit, launch it or keep it depending on what the experiment was, and bring it back. And we were going to have this standard bus that was going to be one of the big improvements in cost of the science payloads. So we showed a reduction in the cost of scientific activity in our cost effectiveness studies – that never happened. Since guys never could accept the idea of an independent bus.