Feynman’s Challenger appendix

In the aftermath of the Space Shuttle Challenger disaster of 1986, a Presidential Commission was established to determine what went wrong. The most unusual member of the panel was almost certainly the physicist Richard Feynman, some of who’s books I have reviewed. Ultimately, his contribution proved to be controversial and was shifted into an annex of the official report. To me, it seems like a remarkably clear-sighted piece of analysis, with wide-ranging importance for complex organizations in which important things might go wrong.

The full text is available online: Appendix F – Personal observations on the reliability of the Shuttle

He makes some important points about dealing with models and statistics, as well as about the bureaucratic pressures that exist in large organizations. For instance, he repeatedly points out how the fact that something didn’t fail last time isn’t necessarily good evidence that it won’t fail again. Specifically, he points this out with reference to the eroded O-ring that was determined to be the cause of the fatal accident:

But erosion and blow-by are not what the design expected. They are warnings that something is wrong. The equipment is not operating as expected, and therefore there is a danger that it can operate with even wider deviations in this unexpected and not thoroughly understood way. The fact that this danger did not lead to a catastrophe before is no guarantee that it will not the next time, unless it is completely understood. When playing Russian roulette the fact that the first shot got off safely is little comfort for the next. The origin and consequences of the erosion and blow-by were not understood. They did not occur equally on all flights and all joints; sometimes more, and sometimes less. Why not sometime, when whatever conditions determined it were right, still more leading to catastrophe?

In his overall analysis, Feynman certainly doesn’t pull his punches, saying:

Since 1 part in 100,000 would imply that one could put a Shuttle up each day for 300 years expecting to lose only one, we could properly ask “What is the cause of management’s fantastic faith in the machinery?”


It would appear that, for whatever purpose, be it for internal or external consumption, the management of NASA exaggerates the reliability of its product, to the point of fantasy.

It certainly seems plausible that similar exaggerations have been made by the managers in charge of other complex systems, on the basis of similar dubious analysis.

Feynman also singles out one thing NASA was doing especially well – computer hardware and software design and testing – to highlight the differences between a cautious approach where objectives are set within capabilities and a reckless one where capabilities are stretched to try to reach over-ambitious cost or time goals.

Of course, the fact that the Space Shuttle was more dangerous than advertised doesn’t mean it wasn’t worth the risk to launch them. Surely, astronauts were especially well equipped to understand and accept the risks they were facing. Still, if NASA had had a few people like Feyman in positions of influence in the organization, the Shuttle and the program surrounding it would probably have included fewer major risks.

Obama and manned spaceflight

Apparently, Barack Obama is thinking of curtailing NASA’s future manned spaceflight activities. Specifically, there has been talk of canceling the Ares 1 rocket and scaling back the Orion Crew Exploration Vehicle. If true, the news is welcome. There is very little evidence that ongoing manned programs – including the Space Shuttle and International Space Station – are generating useful science or providing other benefits. There is even greater doubt about the usefulness of returning to the moon.

Space exploration is an activity best undertaken by robots. They are cheaper to send up than humans and more capable. Given the very limited value provided by sending live people into space, it is something the United States should discontinue. At the very least, it is something that should be sharply scaled back while the government works to address America’s severe debts and other problems.

What Do You Care What Other People Think

This sequel to Richard Feynman’s Surely You’re Joking covers some of the same ground as the prior book, though it is focused on the inquiry conducted after the Challenger space shuttle disaster. The book includes an appendix to that report, written by Feynman exclusively. Apparently, he was going to remove his name from the findings on account of his section being censored. Eventually, they printed something largely identical to his final copy.

As he explains it, the solid rocket booster failure that destroyed Challenger was largely the result of disjointed and poor communication between layers of administration at NASA and its supplier companies. The statistical modeling of the behaviour of the O-rings in the boosters was very poorly done. Information on the vulnerabilities of the shuttle either did not reach the most senior levels or was paid insufficient heed there. In any case, it seems likely that even if cold weather and design problems hadn’t caused this specific failure, something would have eventually gone wrong anyhow. For example, Feynman describes in detail some technical and procedural issues associated with the main engines. Such problems are not really surprising, given the overall complexity of the vehicle, the ‘top-down’ manner in which it was constructed (designing whole systems before testing individual components), and its fundamentally experimental nature. That being said, Feynman’s assessment probably has continuing relevance for other projects with similar associated risks and management structures. In particular, the contrast he draws between the strong protocols used in programming the shuttle’s computer – as compared with the protocols for sensors and engines – demonstrates that it is possible to do things well, provided sufficient attention and resources are devoted to the task.

Overall, the previous book is more entertaining and shows more of Feynman’s character. Aside from a section on Feynman’s first marriage, as well as the illness and death of his first wife, this book focuses on the details of Feynman’s investigation, including his famous demonstration with the O-ring and glass of ice water. All told, I found the earlier book more diverse and interesting. This book may be more useful for those whose professional work involves dangerous machines.

Space-related fatalities

I never appreciated just how hazardous spaceflight really was. Everyone knows about the Challenger, Columbia, and Apollo 13 disasters. Many people know about Apollo 1. I doubt anyone reading this is aware of all of these. Soyuz 23, for instance, crashed through the ice of Lake Tengiz and had the crew saved only through an elaborate underwater rescue. Apollo 12 was struck by lightning during launch and would have been destroyed if disabled computers in the crew compartment hadn’t had backups in the rocket itself.

Of the 439 people who have been strapped into a vehicle intended to eventually go into space, 22 (5%) have died as a result. American astronauts were statistically about four times as likely to die as their Soviet counterparts, though that is partly a result of how the large crew of the Space Shuttle means a catastrophic accident kills seven people. The Space Mirror Memorial in Florida commemorates Americans who have died in the space program; their cosmonaut contemporaries are buried in the Kremlin Wall Necropolis. No Russian has died in relation to space travel since the fall of the Soviet Union, so it is unclear how they would be memorialized now.

The Shuttle shows you its belly

In order to permit an inspection of the thermal tiles that protect the vehicle from the heat of reentry, the Space Shuttle did a backflip for the cameras while orbiting at abouty 7,700 metres per second. This was done using the dual hypergolic engines of the Orbital Maneuvering System, burning monomethylhydrazine with a nitrogen tetroxide oxidizer. The BBC has a relatively low resolution video of the event.

The foolishness of the International Space Station

Montreal courthouse

On Tuesday, the space shuttle launched once again on a mission to add another piece to the International Space Station (ISS). As I have said before, it is a needlessly dangerous, unjustifiably expensive, and rather pointless venture. The science could be equally well done by robots, without risking human lives, and without spending about $1.3 billion per launch (plus emitting all the greenhouse gasses from the solid rocket boosters and related activities).

More and more, the ISS looks like a hopeless boondoggle. The lifetime cost is being estimated at $130 billion, all to serve a self-fulfilling mandate: we need to put people into space to scientifically assess what happens when we put people into space. Furthermore, the window between the completion of the ISS in about 2012 and the potential abandonment of the station as soon as 2016 is quite narrow. Robert Park may have summed up the whole enterprise best when he remarked that:

“NASA must complete the ISS so it can be dropped into the ocean on schedule in finished form.”

Normally, I am a big supporter of science. I think funding the International Thermonuclear Experimental Reactor and Large Hadron Collider is wise; these machines will perform valuable scientific research. Likewise, I support the robotic work NASA does – especially when it comes to scientists looking down on Earth from orbit and providing valuable research and services. I support the James Webb telescope. I also support the idea that NASA should have some decent plans for dealing with an anticipated asteroid or comet impact. The ISS, by contrast, is a combination between technical fascination lacking strategic purpose and pointless subsidies to aerospace contractors.

Of course, the Bush plan to send people to Mars is an even worse idea with higher costs, more risk, and even less value.

Contemplating the future

Shadows of me and Emily Paddon

The Stardust Mission

One piece of exciting news today is the safe return of the NASA Stardust capsule, after a seven-year mission intended to collect dust from the tail of a comet. If the aerogel-filled compartments are, as expected, saturated with this material, it will be the first time such a thing has ever been collected and it may contribute important information to understanding the early solar system.

This is also the first mission since 1976 to return solid material from an extraterrestrial body: a measure both of diminished interest in the moon and the exceptionally longer distances involved in reaching other planets and asteroids.

Whereas there is a great deal of controversy about the usefulness and safety of manned space travel – especially the Shuttle Program – there are few people who contest the scientific usefulness of robotic exploratory missions. Indeed, there is a very satisfying record in the past few years of improved understanding of cosmic phenomena, both within and outside our solar system.

The really exciting prospect is the possibility of seeing new developments in particle and theoretical physics start to match up better with improved cosmological models. The biggest questions in physics today are probably the questions related to dark matter and energy, the explanation behind the profusion of subatomic particles that have been discovered, and the generation of a theory that is able to deal with the contradictions between quantum mechanics and relativity. While this mission doesn’t necessarily speak directly to any of those goals, it’s part of a process of improved data collection that feeds the development and testing of explanations. It seems likely that interesting times are ahead.

The second term schedule

On Tuesday, the second core seminar begins: Contemporary Debates in International Relations Theory. While the subject matter is inherently somewhat less interesting than the historical analysis of the first and third term, I am excited about the course. Partly, that is because of the instructors: David Williams and Jennifer Welsh. Partly, that is because of my fellow seminar members. If I recall correctly, I am in the same group as Roham, Sheena, Andy Kim, Bryony, Claire, Robert Moore, Emily, Matt Pennycook, Shohei, Alex, and Robert Wood. Collectively, I think this will make for interesting discussions.

Just like last term, I have a one in seven chance of being called upon to give a fifteen minute presentation on one of the week’s two topics. This week, mine would be:

‘For classical realists conflict stems from human nature, while for neo-realists conflict stems from the nature of the international system’. Is this an accurate assessment of the differences between classical and neo-realists?

Thankfully, I have some recollection of Robert Crawford’s IR Theory course at UBC to fall back upon. The sensible approach seems to be to quickly summarize and contrast some of the biggest names in realist theory: E.H. Carr, Hans Morgenthau, and Kenneth Waltz, in particular. Tomorrow, I will be in the SSL formulating some speaking notes.

Aside from the core seminar and qualitative methods, I am not entirely certain what we are meant to be attending this term. I’m not sure if the ‘Advanced Study of IR’ course is persisting into the second term; nor am I certain about whether the ‘Philosophy of the Social Sciences’ course that was delayed in Michaelmas will be happening now. Then there are things like the undergrad IR lecture and the ‘Professional Training in the Social Sciences’ course that were poorly attended and never discussed last term. I am sure it will all become clear in the first week or so, and I can ask Dr. Hurrell about it in our first supervision.

One thing I am scrambling over is the ORS application. For some reason, I thought it was due months from now. As such, I am having a real struggle coming up with two letters of reference before the due date on the 20th. That is particularly true since Dr. Hurrell is not supposed to provide one, since the department will be making the selection of which ORS applicants in the program get passed along to the university. It’s frustrating to have to do all of this for a scholarship we’ve told we have almost no chance of actually receiving. I am personally more hopeful about the Chevening, for which all applications were due in Ottawa today, and a few others that are coming up in the next few months. Suffice it to say that having some funding for next year would be exceedingly welcome.

Housing for next year and a job for the summer

Both at the back of my mind for the whole break, neither of these problems has found a solution yet. I am increasingly inclined to staying in Oxford: partly because of the availability of research materials for my thesis and partly due to the lower cost of living and the correspondingly increased probability that I will be able to find a job that will at least cover them. I would be happiest with a job doing academic research or working as a writer or editor in an academic, journalistic, or publishing context. Anyone with ideas is very much encouraged to contact me.

I have preferences but no possibilities regarding housing as well. I’d like to have a room in a house shared among some of my friends (ideally, at least a few of them members of the M.Phil in IR program). The Jericho and the Cowley Road areas seem to be the desirable ones for students. Jericho is closer to university stuff, but is less of a low-cost residential environment. The existence of the Tesco on Cowley Road could single-handedly account for a somewhat lower cost of living there. As for the building itself, my critical requirements are:

  1. High speed internet access.
  2. Decent security – I really can’t afford to have my laptop stolen
  3. A clean and effective kitchen
  4. Tolerable proximity to classes and services
  5. Affordability

Of course, a big part of the quality of any living arrangement has to do with the people with whom you are living. My thuggish former roommates from my first year in Fairview may be the ultimate example of how bad roommates can ruin a residence experience. While I don’t think I could possibly do that badly again, I’d really like for my first experience in private accommodation to be with people whose company I enjoy. This will be the first time I’ve ever rented a private room. At UBC, at L’Universite de Montreal, and at Oxford, so far, I have always lived in university housing.

I may well apply for a space in Merifield, just so that the option of living there remains open.