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Shuttle  =  The Space Shuttle
Factor  =  One Mistake that Produced A Thousand Problems and Ruined the Space Program


"Dynamic Overshoot" In "Space Systems"

The following 4 documents can also be found on www.nasa.gov / Human Space Flight Committee (Augustine Committee)/Related Documents.

Bridging Knowledge Gaps in Space Systems (PDF 16KB)
Letter to Augustine Committee (7/30/2009): 

"The National Academies, NSF, GAO and others agree today that “knowledge gaps” and shortcomings in science, technology, engineering and mathematics (STEM) subjects have undermined modern systems, especially, space systems. The shortcomings produced cost overruns, schedule slippages, problematic operations, expensive maintenance, short life and random failures. Bridging the knowledge gaps is vital to reinvigorate our space program, economy, education and world leadership."

The Problem with the Space Shuttle and Space Program (PDF 975KB)
Report (1992, 2000, 2003) submitted to Augustine Committee: 

"My transient “dynamic overshoot” studies caused controversies since 1986. The Report I submit for the Committee’s consideration on this subject is rather lengthy. To counter detractors, I found it necessary to discuss the ontological reality and epistemological foundation of the phenomenon, include overwhelming empirical evidence, straightforward mathematical analysis, sobering line of reasoning, and many relevant and, perhaps, irrelevant, opinions to shore up my case. It remains my opinion that the transient dynamic overshoot phenomenon has been the primary problem with the Space Shuttle and the Space Program."

Wave Modulations in Space Systems (PDF 21KB)
Letter to Physics Today (6/29/2009) Submitted to Augustine Committee: 

"According to Heraclitus, the advocate of change, nature loves to hide, for example, 30m waves. The study of huge sudden rogue waves by Chris Garrett and Johannes Gemmrich (physics today, June 2009, page 62) describes a phenomenon that is difficult to reproduce in the laboratory and resistant to mathematical analysis. Relevant to this subject, I did extensive research in the 1980s-90s, which resulted in the Patent, “Method for Producing Natural Motion.” In many tests, I produced sudden extra-large waves by straightforward modulation of waves, as described below. This has not been done before."

Transformative STEM Subjects and More  (PDF 17KB)
Letter to National Science Foundation (5/12/2009) Submitted to Augustine Committee: 

"There is a conspicuous “knowledge gap” between the Galilean-Newtonian mechanics and modern energetics. This is the sudden jump taken from the concept of force to the energy conservation principle, which should be familiar to all physicists and engineers. According to the textbooks, the sudden jump is taken to simplify problem solving. But failing to bridge the “gap,” 20th century classical physics remained incomplete and modern physics lacked a vital cornerstone in its development. The last serious attempts to bridge the gap were taken by Hertz, Mach and Boltzmann at the end of the 19th century, but as noted by Einstein, Poincare and others, the central problems were not resolved."


The Problem with the Space Shuttle and the Space Program [Shuttlefactor]
Detailed explanation of the transient dynamic overshoot effect
1992, 2000, 2003 (PDF 970KB)

Postscript August 25, 2009

The Obama Administration is facing another daunting task – the space program – not unlike the overwhelming tasks that it has undertaken with the economy, health care, education, etc. Some advocates of human space flight want the President to commit the Nation to go to Mars right away. Build the Ares-I rocket. Build the big Ares-V rocket. Pack it up, and let’s go. Some want us to go back to the Moon soon. Only a few sober voices seem to realize the stark fact that we can hardly send humans to Low Earth Orbit (LEO) reliably and economically. And the “gap” is staring us down, i.e., we will buy seats on Russian rockets to visit one of our big investments, the International Space Station. The problems are many and deep-rooted. The space Initiative of only 20 years ago promised to return us to the Moon in 2004, which didn’t happen, go to Mars in 2014, which will not happen, and have a thriving space program by now (2009), which it isn’t. The 5-year old space Vision is already in trouble. What’s going on? How did all of this come about? What’s the way out?

For those of us who worked in the space program in the 1960s and 70s, something seems farcical about the present situation. Back then, we did not have space textbooks or handbooks, we didn’t have desktops or laptops, we didn’t even have hand held calculators. Similar hi-tech tools were not available to the economists, but the economy prospered. Yet, with all the modern tools, the economy nearly collapsed last year. Is our space program on a down turn that can be quickly turned around? Or, is it near, or in, a meltdown condition?

I don’t think anyone could have predicted the economic crisis of 2008 twenty years ago. But, engineering is a precise art, and one can predict the consequences of major mistakes, or outright blunders. This lengthy Report describes such a blunder; I call the dynamic overshoot, or dynamic transient, effect. Get a cheap slinky, put a weight on one end, hold part of the slinky in your hand and release the weight: Watch carefully and think about it; you will recognize the “dynamic overshoot.” This Report describes with ample evidence how one mistake undermined the whole space program.

In a meeting with a large group of engineers at the Kennedy Space Center in October 1986, I discussed the “dynamic overshoot” mistake in detail. The Director of Shuttle Engineering asked for a copy of my written notes. In those notes, I asked in writing, “Are there instruments to measure transient response to step-input?” (See Figure 67). The transient behavior of the Shuttle was completely messed up from the start. I subsequently mounted a massive and expensive effort from 1986 to 92 to describe the mistake and its consequences to the White House, the Congress, the Aerospace Contractors, the Professional Organizations, the Universities and the media, as you will read about in this Report.

Later this week, the new Ares-I rocket will be tested. I ask my above 1986 question again, “Are there instruments to measure transient response to step-input?” The magnitude of the “dynamic overshoot” effect, particularly for solid rocket motors, is so massive that the White House, the Congress and the American public must know the exact “dynamic overshoot” measured for the Ares-I. Will the “dynamic overshoot” be measured? Will it be measured correctly? How will the measurements of Ares-I differ from the hodgepodge guesses used with the Space Shuttle? Was the “dynamic overshoot” calculated, and computer simulated, correctly before the test? How will the test results compare with the calculated and computer-generated values?"


"Have you ever had your car repaired for the same problem 3, 5, or 7 times? The mechanic explains the reasons for changing a part under the hood; you understand and pay the bill. Then another part, another bill, yet the problem persists. You go to a shop with ultra-modern equipment, they change other parts, more bills, but the problem lives on. Finally, you pull into a simple shop on a country road and a friendly fellow makes a simple adjustment, explains the reason for the adjustment, a small bill; to your unexpected delight, the problem is gone. The same scenario happens to people with the heating, electrical, water or other systems in their homes. The aerospace-structural-dynamics experts will shout that the analogy is not fair. It is. If you do not know the cause of a problem, you will run around in circles fixing the wrong things, while the causal problem lives on. The devastating dynamic overshoot 100% mistake lives on."


"The deep roots of the “dynamic overshoot” mistake are discussed in this Report. The discussion includes scientific, technical, educational, historical, philosophical, psychological and political elements of the design blunder. The Report shows (1) how some engineers are completely unaware of the “surge” effect in physical systems, (2) how some engineers miscalculated and mishandled the effect in Shuttle design, (3) how the engineers actually measured the correct “surge forces” in the Shuttle in 1982, but did not even realize the meaning of the correct measurement, (4) how Newton’s Action-Reaction Law is at the root of the problem, (5) how scientists and engineers mistakenly and regularly equate the cause and effect, input and output, action and reaction, and forcing function and transient response in mechanical start-up transient situations, and (6) how relying nearly exclusively on pressure measurements (which do not show the “surge” effect), physicists and rocket engineers repeatedly fell into the tricky “dynamic overshoot” trap, with drastic results."

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From "Space Systems" to "Nuclear Reactors"

The Correct Way to Handle Transient Loads
May 19, 1993

Early in the century, the explosion of temperamental boilers killed people and destroyed industrial and residential centers. Halfway through the century, jet powered aircraft crashed unexpectedly, killing people and causing considerable losses. In the beginning of the space program, the hallmark of rockets was the huge explosions soon after ignition and the destruction of valuable payloads and launch facilities. Then there were the nuclear reactor incidents: Three Mile Island (TMI) which frightened a large community and a nation, and Chernobyl which devastated communities and shocked the world. What these systems have in common is that they are pressure-activated, and the mechanical engineer plays the central role in their design, construction, operation, safety, and reliability. Where are we today?

Have we (mechanical engineers) overlooked something fundamental in our work? The answer is a resounding yes. One basic error has undermined the safety, reliability and economy of important systems throughout the century.

…The nature of the error can be appreciated from the observation that the pressure does not overshoot, nor should it be expected to overshoot.

…The boosters were repeatedly strengthened, particularly, after the Challenger accident; and the number of uses should have gone up, and not down. Yet in 1990, three segments failed irreparably after only one (1) mission. At this rate, we are not going to Mars; we are not going back to the Moon; and we will hardly make it to low earth orbit; which is where we are today (May 19, 1993). Something is fundamentally wrong in mechanical engineering. Something is fundamentally wrong in the mechanical curricula and textbooks. A radical change in mechanical engineering education and practice must take place to remedy the fundamental oversight.

Transient Loads in Nuclear Power Reactors
Letter to ASME, May 20, 1993 (PDF 650KB)

…to find some 20 pages that will highlight the problem, particularly, in pressure vessels, including, nuclear reactors as we discussed yesterday. Most of the papers are lengthy, with greater emphasis on the same problem in aerospace systems, and include specific numerical examples from real systems. I believe the enclosures and the following commentary will provide a glimpse of how the transient loads have been [mis]handled in nuclear reactor pressure vessels and related hardware. I will be glad to answer your, or other experts’, questions.

There is no indication whatsoever that the pressure-time profiles are the forcing function in transient conditions.

This is fine if the transient is measured separately and directly. But, the transient parameters are not even included. The pressure measurement is strictly the “forcing function” and it must be used to derive the transient response analytically, which then requires interpretation.

While most other papers that I have reviewed show simple conversion of pressure to stress, this paper shows that the “transient” concept is very seriously muddled.

Similar curves are very popular in aerospace systems. Actually, they are the only kind available for rocket engines and motors, jet engines, etc. The measured pressure very nearly tracks some computer predictions. Well of course they should. The two are the same parameter!

I recommend that you do not accept the common clichés: We know about transients; We always take the forcing function and derive the response, etc. If the forcing function and the response look like the curves shown in the enclosures, then the transient is not understood, let alone derived.

Yet, not one single paper presented a true “transient response.” I emphasize again that a pressure measurement shown to be similar to some computer code, or vice versa, is not a transient analysis. It is the same parameter shown to equal itself, which it should.

See also, “Radiation Embrittlement and Surveillance of Nuclear Reactor Pressure Vessels: An International Study,” Conference sponsored by IAEA, ASTM Committee E-10, 1981; and similar references.

Safety of Nuclear Power Reactors In Transient Conditions
Letter to Dr. Stanislav Fabic, June 3, 1993 (PDF 925KB)

Reference to your letter of May 29, 1993, it concerns me a great deal that you could not recognize the enormity of the widespread error described in my write-ups. The safety, reliability and economy of important systems, including nuclear reactors, have been (and continue to be) severely compromised by the lack of understanding of transient loading conditions. This is not simply a matter of “a different opinion about causes-and-effects;” it is about a clear understanding of the causes and the effects, as they are. Since your views will be persuasive to the NRC, ASME, and others, I will clarify some matters and I hope that you reconsider your earlier conclusion.

…a clear distinction must be made between the pressure (cause) in a vessel, and the stress (effect) in the materials that make up the vessel.

…that the force magnification I propose is like “getting something for nothing.” I am including a couple of pages from Machine Design and Vibration textbooks, which show the doubling effect. In two simple steps, the equations simplify to: F = 2F!!

It just happens that in all the technical papers and the panel discussions, in which you participated, on the safety of nuclear reactors in transient conditions, the stress is derived directly from the pressure readouts. The stress simply follows the pressure. There is no overshoot in the stress. This means that there was no transient analysis whatsoever, correct or otherwise; even though the word “transient” was widely used. The practice was done even when the pressure build-up occurred in less than 10 milliseconds. At this rate, Sir, the “forcing function” is nearly a unit-step-function; and correct transient analysis will show that the effect of the load on some parts of the system is nearly doubled… The pressure-time curve is not the transient response.

The problem is trivial, but it is not obvious, though it is very important.

You are thinking in terms of pressure fluctuations, which you call in your letter “pressure overshoot.” This is a central part of the problem. The pressure does not overshoot. My weight does not magnify when I step suddenly on a weight scale… there is a distinct difference between the pressure fluctuation and the force overshoot. These differences have not been taught at the undergraduate or other levels.

Other transient experts recently dismissed my assertions out of hand because they say that modern pressure transducers are extremely sensitive and, hence, must pick up the transient response. Please refer to my enclosed figures (6a). The pressure transducers do not, and cannot, measure nor detect the overshoot! These experts consider my assertions idiotic. I repeat, the pressure transducers do not, and cannot, measure nor detect the overshoot!

Shock Absorbers and Damping Isolators for Space Systems
September 1993

A conspicuous dynamic effect exists when a car is driven over a speed bump, such as found in parking lots. Once the speed bump is safely cleared, the car encounters lesser dynamic conditions in a typical journey. Without the shock absorbers, vehicles and cargo must be stronger, thus heavier, to avoid damage.

At liftoff, rockets experience a shock effect similar to driving over a speed bump… This is when most rockets have exploded or failed.

To offset the loss of payload capacity, major programs have been initiated, e.g., increase thrust with the Advanced Solid Rocket Motor (ASRM), or develop exotic aluminum-lithium alloy for the External Tank. But, these measures do not eliminate the detrimental start-up overshoot effect.

Instead of strengthening all the parts of a system, it is more effective to use shock absorbers, isolators or other dampers. A properly designed collapsible and locking device or material can isolate the parts of a vehicle and the payload from the transitory effect… Expandable dampers can be used for expendable vehicles, upper stages, and payloads. Reusable dampers, such as dashpots, will be worth the effort of development for reusable hardware.

It is more effective to absorb the excess loads with one device than to design all the parts to withstand the transient loads.

Transient Conditions in Wind Tunnels
February 1994

Measuring the true maximum transient loads in every part of a system is formidable. It requires the instrumentation of every part, which is not practical for systems that are made up of thousands, or tens of thousands, of parts. In the proposed work, critical parts that experience the maximum transient effects will be identified, the actual maximum transient parameters will be measured, and methods of extrapolation of the calculated loads for the other parts will be established, or confirmed.

To achieve the goal, modifications to the wind tunnel, or additions, will be required.

For example, the entry or exit of aircraft into wind shear pockets of definite size and speed. The tests will determine the pointing accuracy of directional systems subjected to sudden wind gusts. Other examples include the start-up, throttle-up, throttle-down, and shut-down of pressure-activated systems, such as, jet or rocket engines, reactors, etc.

A 1972 Counter for the Space Shuttle
Article submitted to The Space Review, 2/26/2009 

"Here is my 1972 Shuttle-Counter. After fuming over it, take a deep breath and contemplate it again. The first Columbia flight in April 1981 should have been roughly flight STS-200. The Challenger 51L in 1986, the 25th flight, should have been STS-500. The Columbia 107 in 2003 should have been STS-1,500 (yes, one thousand five hundred), and so on. We should have had some 2,000 Shuttle flights by now, and not only 120-plus “problematic” flights

 - - - At 65,000 lb per mission, we would have had over 100 million pounds launched into LEO, enough hardware, fuel and provisions to do the many things that only seem a dream today."

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From "Dynamic Overshoot" to "Pulsing Thrust "

In June 1986, after the official Challenger investigation was finished, AbuTaha discovered from the Report of the Presidential Commission that a first-order effect, known as the start-up transient “dynamic overshoot” effect, was neglected in Shuttle design and the investigations.

The “dynamic overshoot” mistake was described to a large NASA team of engineers behind closed-doors in October 1986. The Director of Shuttle Engineering at the Kennedy Space Center (KSC) recommended  immediate study of the subject by AbuTaha under Purchase Order (PO) Agreement with NASA.

NASA then canceled the PO agreement. Apparently, anonymous engineers from the Marshall Space Flight Center (MSFC) were furious that AbuTaha discussed the liftoff loads with the KSC experts.

In response to questions from Senator John Kerry of Massachusetts about excess forces and excess stresses in the Space Shuttle, NASA told the Senate that it was taking those issues seriously. AbuTaha stepped aside to let the agency deal with the “excess forces” and other issues, and he did not write publicly about the dynamic overshoot mistake.

Three years later, AbuTaha discovered that the NASA experts did not correctly address the “dynamic overshoot” issue, and he began to write about it.

By 1990, AbuTaha discovered that the “dynamic overshoot” effect was not considered in some important systems on the Hubble Space Telescope (HST), and he took his findings to NASA, the Administration, the Congress, and the HST office.

The initial launch of the HST was delayed for 2 weeks while AbuTaha’s assertions were investigated. At the time, Vice President Dan Quayle, White House Chief of Staff John Sonunu and NASA Administrator Richard Truly traveled to the Johnson Space Center (JSC) to check out the HST situation, as described on local DC television news.

The leaders returned from JSC in Texas. AbuTaha’s concerns were apparently refuted. He did not hear from anyone about it. The Hubble was launched. We almost lost the HST, a national treasure. The news concentrated on a problem with a mirror. There were other problems with Hubble, including solar panels, gyroscopes, and other important systems. NASA would later reveal that “fuses” on the Hubble were changed because of the transient “dynamic overshoot” effect.

For months, AbuTaha tried to find out what was the NASA rebuttal that allowed the launch of the HST. He was asserting “dynamic overshoot” of 70 to 100%. NASA was asserting that “dynamic overshoot” was only 1 to 3%. The difference between the two assertions exceeded the built-in safety margins for the Space Shuttle. The astronauts were potentially flying with a vehicle that had zero or negative safety margins.

AbuTaha was unyielding in his position. NASA was unyielding in its position.

Finally, a Congressional Staff member, who attended briefings about the JSC-HST rebuttal, told AbuTaha that NASA had shown the officials actual test results that showed “overshoots” of 1-3%. Impossible. How could that be? Discussing it further, the Staffer “casually” said that NASA used the most sophisticated “pressure transducers” in their measurements. Finally, light at the end of the long tunnel. He was talking about "force dynamic overshoots," which are real. NASA was talking about "pressure dynamic overshoots," which don't exist.

Paul J. Weitz, Acting Director, Johnson Space Center, confirmed the Congressional Staffer's input. Weitz sent AbuTaha a letter on the subject on October 13, 1992. The following letters explain how the massive difference of opinion on the "dynamic overshoot" mistake was explained. The start-up transient studies led AbuTaha to a novel invention, to double the specific impulse of rockets and engines, which is also discussed in the letters.

Letters on Dynamic Overshoot and Pulsing Thrust - 1992

AbuTaha to Daniel S. Goldin, Administrator, NASA, September 21, 1992

We informed your office last month of our "pulsing-thrust" technique for rocket engines and motors. The process provides superior performance for space systems, and it should be of particular interest to NASA.

Paul J. Weitz, Acting Director, Johnson Space Center, to AbuTaha, October 13, 1992

"Thank you for your proposal of September 22, 1992. It has been reviewed by technical personnel in our propulsion department. Their analysis indicates that using a pulsing thrust technique for rocket engines and motors could not be used for improving propulsion systems presently required by the Johnson Space Center… Therefore, the specific impulse increase predicted for engines using the “pulsing-thrust” technique will, in fact, not occur. (my emphasis)

The dynamic overshoot “near-doubling” you state on page 2 of your proposal does not occur in Space Shuttle main engine startups. Chamber pressure is intentionally controlled to prevent overshoots greater than 2 percent above rated thrust level during the approximate 5-second Space Shuttle main engine start transient. "

AbuTaha's Response to Paul J. Weitz, November 23, 1992

"Your letter reveals that serious misconceptions about the overshoot effect prevail. A clear understanding of the effect is requisite to see how to achieve the pulsing-thrust advantage. I will give a concise description of the confusion. I will also share this clarification with other Centers to avoid repeating the same points.

Either the overshoot is less than 2 (two) percent, as you assert, or it is greater than 70%, as I have stated. The difference is so enormous and consequential that it must be resolved. The significant disparity in our positions is the result of confusion, which I will explain.

This sentence reveals the extent of the confusion. It is correct to say that the “thrust” overshoots at start-up, but it is absolutely incorrect to say that the “chamber pressure” also overshoots. The pressure does not overshoot during start-up transients. It merely fluctuates! Let me explain.

By mistakenly believing that the “chamber pressure,” which does not overshoot, is the measure of the overshoot, your experts have mixed up the input and the output, or the cause and the effect.

Notwithstanding that the technical personnel in your propulsion department had dismissed my proposed pulsing-thrust advantage, I am available to give the specific details of the technique in a NASA sponsored Seminar, or Colloquium.

AbuTaha to Aaron Cohen, Acting Deputy Administrator, NASA, November 23, 1992

...The enclosed letter to Mr. Paul J. Weitz at JSC explains the serious mix-up by the other experts, as best as I can describe it... then, perhaps, my persistence, and not the irritation, will be remembered.

Reference to the pulsing-thrust technique, which I brought to your attention before, some experts have already dismissed the process before even seeing the detailed analysis and specific steps required to achieve the proposed thrust advantage...

AbuTaha to R. J. Lee, Director, MSFC, NASA, November 23, 1992

Thank you for your kind letter of September 24, 1992. Due to personal circumstances, I have not been able to prepare a detailed unsolicited proposal on the pulsing-thrust technique. My patent application requires considerable amendments, which when completed will show the applicability of the method to a variety of systems, in addition to rocket engines and motors.  

AbuTaha to Pierre J. Madon, Vice President E&R, INTELSAT, November 9, 1992

...The first equation in your mathematical analysis clearly shows the dynamic overshoot doubled-response. The advantage is there, and the question is how to harness it.

As to my shuttle-related study, the Institution of Mechanical Engineers in the UK had reviewed my 1992 paper and described it as "an excellent piece of work with far-reaching consequences." There have been other favorable reviews by other competent experts... As a citizen of the United States, I take exception to your criticism of my conduct in that case. Strictly, out of consideration to NASA and to the (U.S.) national security, I had shared the specifics of my results ONLY with NASA in 1986 in closed-door meetings. I might add that the near-doubling dynamic-overshoot effect was also overlooked in the design of other systems, including the INTELSAT systems. The dynamic overshoot effect is generally not even discussed in engineering textbooks on spacecraft design and propulsion.

[Note: "Pulsing Thrust" is AbuTaha's Invention to double the thrust of rocket engines and motors. Several leaders in the aerospace industry expressed interest in the Invention, e.g., a Rocketdyne executive told AbuTaha, "If it is what you say, we're interested," and Norman Augustine, then Chairman of Martin Marietta, referred the Invention to top engineering  officers at the Company for evaluation. But, the senior  engineers from NASA, the aerospace industry, aerospace professional organizations and universities dismissed AbuTaha's invention out of hand. Some senior engineers went as far as to submit to AbuTaha mathematical analysis to show that the Invention was impossible. Today, in 2009, "doubling the thrust" Invention is a reality and there are hundreds of technical papers about it on the Internet. The Weitz' above letter was one of the few polite dismissals of the Invention [See "Pulsing Thrust" webpage for more details].

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