After reading the 248-page Columbia Accident Investigation Board report in its entirety, it is now time to comment on its contents and to recommend a space program for the future that we should all be able to agree upon. As the Board noted in its report, the lack of a unified vision for the future was a key ingredient in the Shuttle disaster, as NASA tried and failed to be all things to all people.
The Columbia Accident Investigation Board (CAIB) released its report on August 26
th, 2003. Within hours, TV and radio commentators were talking authoritatively about its contents. Newspapers did the same the next day, and this continued through a 48-hour news cycle, which wasn't even enough time to read the report. It is little wonder that Americans are ill-informed about its contents.
According to the mainstream media, the CAIB report blasted NASA and firmly affixed the cause of the
Columbia disaster as the foam insulation which broke free from the external fuel tank. This is a gross oversimplification of the report's conclusions. In fact, the report blames several White House administrations for failing to develop a coherent policy for the space program, and then blames Congress for continuous changes in its requirements on NASA. Only then does the report blame NASA for trying to be all things to all Congressmen, for failing to fully implement the recommendations of the Rogers Commission after the
Challenger disaster and for requiring NASA engineers to prove that
Challenger and
Columbia were unsafe to fly, rather than requiring engineers to prove that they were safe to fly. Even this statement is necessarily a simplification of the 10 Mb report, which everyone should be encouraged to read from cover-to-cover
[1].
The Board's rigorous use of sound engineering principles in their investigation and their firm resolve to exclude from their investigation any tactics or bureaucratic tendencies that conflicted with these principles is impressive. The result is a document which will serve as an authoritative reference for the top-down overhaul of the space program in America. The Board only left out one requirement that would further serve to facilitate its recommendations: Every president, every Congressman and every NASA employee from this moment forward should be required to take and pass an exam written by the CAIB on the report's contents.
One point in the report which cannot be emphasized enough, is that despite best intentions, unpredictable events will occur in man's adventure into outer space. Some excerpts from the report will serve to clarify just how unpredictable these events can be:
It is our view that complex systems almost always fail in complex ways… — page 6
Aircraft seldom crash these days, but rockets still fail between two and five percent of the time. This is true of just about any launch vehicle — Atlas, Delta, Soyuz, Shuttle — regardless of what nation builds it or what basic configuration is used; they all fail about the same amount of the time. — page 19
It is the Board's view that, in retrospect, the increased complexity of a Shuttle designed to be all things to all people created inherently greater risks than if more realistic technical goals had been set at the start. — page 23
Conditions in certain combinations during ascent may also have contributed to the loss of the foam ramp, even if individually they were well within design certification limits. These include wind shear, associated Solid Rocket Booster and Space Shuttle Main Engine responses, and liquid oxygen sloshing in the External Tank. Each of these conditions, alone, does not appear to have caused the foam loss, but their contribution to the event in combination is unknown. — page 53
Localized penetrations of the protective coating on RCC [Reinforced Carbon-Carbon wing leading edge] components (pinholes) were first discovered on Columbia in 1992, after STS-50, Columbia's 12th flight. Pinholes were later found on all Orbiters, and their quantity and size have increased as flights continue. Tests showed that pinholes were caused by zinc oxide contamination from a primer used on the launch pad. — page 56
Every bolt catcher [a device designed to catch the head of the explosive bolts used to separate the External Tank from the Shuttle] tested failed well below the expected load range of 68,000 pounds. In one test, a bolt catcher failed at 44,000 pounds, which was two percent below the 46,000 pounds generated by a fired separation bolt. This means that the force at which a separation bolt is predicted to come apart during flight could exceed the bolt catcher's ability to safely capture the bolt. If these results are consistent with further tests, the factor of safety for the bolt catcher system would be 0.956 — far below the design requirement of 1.4 (that is, able to withstand 1.4 times the maximum load ever expected in operation). … In addition, STS-107 [Columbia] radar data from the U.S. Air Force Eastern Range tracking system identified an object with a radar cross-section consistent with a bolt-catcher departing the Shuttle stack at the time of Solid Rocket Booster separation. The resolution of the radar return was not sufficient to definitively identify the object. However, an object that has about the same radar signature as a bolt catcher was seen on at least five other Shuttle missions. … The size of this object indicated that it could be a potential threat if it came close to the Orbiter after coming off the stack. — page 87
This examination revealed a strong correlation between [electrical] wire damage and the Orbiter areas that had experienced the most foot traffic during maintenance and modification. — page 88
Laboratory tests on Kapton [electrical wiring insulation] also confirm that on-orbit ultraviolet radiation can cause delamination, shrinkage and wrinkling. — page 89
The Board considers this probability of a critical penetration [from micrometeoroids and orbital debris] to be unacceptably high. — page 94
Maintaining infrastructure has been particularly difficult at Kennedy Space Center, where it is constantly exposed to a salt water environment. — page 114
Organizations cannot put blind faith into redundant warning systems because they inherently create more complexity, and this complexity in turn often produces unintended system interactions that can lead to failure. — page 181
So ingrained was the agency's [NASA's] belief that foam debris was not a threat to flight safety that in press briefings after the Columbia accident, the Space Shuttle Program Manager still discounted the foam as a probable cause, saying that Shuttle managers were "comfortable" with their previous risk assessments. — page 196
The [Rogers] Commission recommended many changes to remedy these problems, and NASA made many of them. However, the Board found that those post-Challenger changes were undone over time by management actions. — page 198
Team analysts at Johnson were asked by managers to demonstrate a "mandatory need" for their [Department of Defense satellite] imagery request, but were not told how to do that. Both Challenger and Columbia engineering teams were held to the usual quantitative standard of proof. But it was a reverse of the usual circumstance: instead of having to prove it was safe to fly, they were asked to prove that it was unsafe to fly. — page 201
The one item we don't want to forget after all of the inevitable finger-pointing between the White House, Congress and NASA, and after the recommendations of the CAIB report have hopefully been codified into law, is that space flight will still be an inherently risky business due to unforeseen and unintended consequences. This points up the importance of Section 10.2 in the report, which talks about crew escape and survival. It is unfortunate that the Board did not see fit to classify perhaps its most important finding as a "recommendation" rather than simply an "observation", but Congress should change the classification, thus ensuring that this requirement is burned into the heart and soul of everyone who designs future space vehicles:
Observation 10.2-1
Future crewed-vehicle requirements should incorporate the knowledge gained from the Challenger and Columbia accidents in assessing the feasibility of vehicles that could ensure crew survival even if the vehicle is destroyed. — page 217
In a previous article, I made the point that it is almost inconceivable that our space vehicles do not incorporate an escape pod, since such pods are now used in sports like Unlimited Hydroplane Racing and many other forms of boat racing
[2]. Our astronauts simply deserve better, especially when the CAIB report found the following:
The Armed Forces Institute of Pathology and the Federal Bureau of Investigation concluded forensic analyses on the remains of the crew of Columbia after they were recovered. It was determined that the acceleration levels the crew module experienced prior to its catastrophic failure were not lethal. The death of the crew members was due to blunt trauma and hypoxia. — page 77
This, combined with the following remarkable statements by the Board, should seal the deal for an escape pod requirement in the future:
Based on NASA's history of ignoring external recommendations, or making improvements that atrophy with time, the Board has no confidence that the Space Shuttle can be safely operated for more than a few years based solely on renewed post-accident vigilance. — page 13
And since NASA believed that the Space Shuttle would be far safer than any other spacecraft, the agency accepted a design with no crew escape system. — page 22
As mentioned in my previous article, NASA did implement a ridiculous bail-out system for astronauts after the
Challenger disaster, where astronauts must blow a hatch and exit their protective surroundings. But during a mission, the shuttle rarely travels at less than 10,000 miles per hour. The wind will rip you apart at such speeds, and the altitudes involved will deprive you of oxygen. NASA's bail-out system is laughable and was only implemented to show that NASA had done something. NASA's position? Flying is inherently dangerous and astronauts accept those risks. Although the first half of NASA's position is true, astronauts should not be required to accept the risks associated with an intentionally deficient design. Enough said on this issue.
As was made very clear in the CAIB report, America also needs a clear vision of its space program for the future, and there is no better place to start on this subject than in contemplating the responsibilities of the public and private sectors in space. It is difficult for anyone who was not around in the late 1950s to understand the fear generated in America by the
Sputnik flight. A little, basketball-size satellite was orbiting above the country, beeping as it went. Why was it beeping? Was the beeping a communication of some sort back to the U.S.S.R.? If so, what was being communicated? Did the satellite contain a camera? What might it be taking pictures of? The questions were endless and the answers were scarce indeed. Only one thing was clear: America needed to be in space for its own self-defense.
No one in the private sector had any commercial reason to be interested in space at the time, nor did the technology exist to get them there if they wanted to go. The federal government was the only entity with the resources to develop the technology, and it had a Constitutional duty to do so since national defense was at stake. Fast-forward 40 years. Space Shuttles are being launched and an entire Space Station is being built to study such things as the flight habits of butterflies in zero gravity. The mission for which the
Columbia crew gave its life concerned itself with investigating an ultra-low energy flame — some 50 times lower in energy than a birthday candle — and a water-mist fire suppression system, among other things. These are proper undertakings for the private sector, not our federal government.
Upon review, it is obvious that the private sector is extremely capable of producing space vehicles at the beginning of the 21st century. A typical example is a company by the name of Spectrum Astro in Arizona, which designed and built
Deep Space I, a spacecraft that exhibited flawless performance over an operating period that exceeded its intended mission lifetime by nearly a factor of three
[3]. Such space vehicles are not only available, they are cost-effective. The price tag for
Deep Space I was $18.7 million.
Companies which have a commercial need to perform research and development in outer space can now do so on their own, and these activities should be properly devolved to the private sector so that NASA does not have a continuing need to be all things to all people.
What, then, should be NASA's role? Constitutionally, there are only four areas with which NASA is allowed to concern itself, and these are defense (upon DoD request), survival, the removal of orbiting debris and Space Traffic Control. These are areas which are either part of our national infrastructure or have a Constitutionally mandated federal role. Of these, we can eliminate defense from the list except in unusual circumstances (such as satellite repair), since the Pentagon no longer uses the Shuttle to launch military satellites. This leaves survival, Space Traffic Control and the removal of orbiting debris. The latter two are self explanatory. The former needs some definition.
By "survival" we are specifically referring to activities which will ensure the long-term survival of the human race in general, and Americans in particular. There are two missions with which NASA can Constitutionally concern itself under this heading. The first is space-based solar power generation. America will definitely need a system to provide power when fuel eventually becomes prohibitively expensive or when environmental factors demand it. The idea for collecting solar power in space where it is strongest and then transmitting it to Earth using ultra-low-intensity microwaves (with an energy density approximately equal to that of a cell phone) was first proposed after the Apollo program. The idea is still viable, and Japan plans to have a 1 gigawatt solar power station in space by the year 2040
[4]. America could put a 15 megawatt pilot plant — expandable to 1 gigawatt — into orbit within 10 years, and it should.
The second mission involves the search for other habitable planets. Like it or not, circumstances beyond our control will eventually require us to at least partially evacuate this rock we call Earth, or face extinction. These circumstances include the impact of near-Earth objects like asteroids. NASA is currently tracking approximately 40 such objects, two of which have been elevated to 1 on the Torino scale (a Torino scale of 10 indicates a 100% impact probability)
[5]. Other possibilities include environmental disasters, regardless of cause, and one certain event that we can count on.
Our sun is continuously using huge amounts of fuel and is converting mass into energy as it does so. This loss of mass decreases the force of gravity which the sun exerts upon the remaining fuel, and the result is an infinitesimal increase in the sun's diameter every day. This, of course, results in an infinitesimal increase in the amount of solar energy reaching the Earth every day. Scientists have been unable to accurately measure the sun's increasing diameter from as far away as the Earth, just as they have been unable to determine what level of solar radiation might present significant dangers to life on Earth. Only three things are certain: someday it will be time to leave, we will then need a place to go, so we need to start looking now.
This points up the futility of NASA's preoccupation with Mars. If the private sector wants to send a probe to Mars to investigate its mineral worth or the possibility that it once contained biological life, let it, but Mars cannot now support human life, and should therefore be relegated to an area outside NASA's mandate.
The search for habitable planets on a reasonable time scale will require NASA to come up with a propulsion system which can attain at least 80% of the speed of light using a one-year acceleration period. This is not as difficult as it might seem. The technology to do so exists, although the challenge is still a daunting one. Neglecting relativistic effects, we know that an acceleration of 1g for one year will allow a space vehicle to obtain the speed of light. Current technology does not actually allow us to obtain light speed for reasons that are beyond the scope of this article, but we can obtain a significant percentage of light speed. A group of equations known as the Lorentz transformations even tells us how much energy is required to do so. The bottom line is that — including relativistic effects — an engine capable of producing a 1.67g thrust at takeoff is required to achieve 80% of light speed in one year (the engine would be throttled to a 1g acceleration rate, making this an expression of the energy required to achieve a 1g acceleration at 80% of light speed). At this speed, a probe can make a one-way trip to Alpha Centauri — the closest star system to our sun, and one which contains the same type of star as our sun — in approximately 6.5 years. That's not bad, but it will also take 4.4 years for the radio communication from the probe to get back to Earth, and if a habitable planet is found, we will then need to launch a manned mission to explore further, which will involve an additional 13-year round trip.
The amount of time required for these missions is skewed slightly by the famous Einstein time dilation phenomenon, which says that the mathematical amount of time noted above for these missions will not be observed by either the space travelers or their friends back on Earth. For a mission profile to Alpha Centauri incorporating a 1-year acceleration to 80% of light speed, a 4.5 year cruise at 80% of light speed and a 1-year deceleration period — which mathematically takes a total of 6.5 years — space travelers would perceive the total amount of elapsed time as 4.5 years whereas the rest of us back on Earth would note that it had taken them 9.7 years to get there, or 19.4 years for the round trip. Knowing all these facts, it is obvious that we can't wait until the last minute, or even the last decade, to start looking for other habitable planets. We must start now. There are 40 stars within 16 light-years of the Earth.
This also means that NASA must stop messing around with investigating the effects of weightlessness in space and start designing space vehicles that provide a 1g environment for space travelers during the cruise flight phase. Humans cannot tolerate calcium and bone loss for such a long period. Since we already know that calcium and bone loss occur in zero gravity, the course for future space vehicle development is well charted and NASA should start working the issue. Further measurements of calcium and bone loss in zero gravity are a waste of time, effort and money.
Moreover, NASA needs to design a "fire and forget" control system for its probes. Control signals from Earth would have a hard time indeed catching up with any probe traveling at 80% of light speed.
Suffice it to say that NASA has plenty to do without getting involved in projects that rightly belong in the private sector. What we need now is a president who will articulate these responsibilities for NASA, a Congress that will back him up, and a NASA organization as good as the one that put a man on the moon.
