Jul 29, 2011

American Roulette

It is summer time. School's out and high schoolers are looking to gain some real-life experience while making some money. Interns, they are called. My company interviews a few kids most summers, and picks one or two, depending on our needs. They are put through an inquis..., er, interview, and the most enthusiastic ones get the gig. A question this year was on Russian roulette.

The person before you squeezes the trigger, survives, and hands the gun to you, the next player. You should:

  1. Spin the cylinder before you squeeze
  2. Squeeze without spinning
  3. Spin or squeeze, it doesn't matter

Our intern chose Option 3. We hired him anyway, and the kid's doing fine. He'll learn. Also, no guns were used for the above thought experiment.
Earlier this month, the Space Shuttle program finally came to a close, after nearly three decades, and I wondered if the interview question should instead have been 
The Space Shuttle program was:

  1. A failure
  2. A disaster
  3. All of the above

I bet our intern would have gotten it right. Well, that would make him smarter than half our population since a poll indicates that half the country thinks that ending the program was "bad for the country!"
I told you the kid's doing fine!
So how do we measure that the program was a failure? Well, it turns out to be not that difficult. You look at the criteria the program defined for its success, and evaluate them against its actual accomplishments.
The shuttle was to be a cheap reusable vehicle, frequently carrying people, satellites and similar payload to low orbits round the Earth. Safely.
How cheap? $50 million to $60 million per flight, give or take a few million. Over its lifetime, it ended up averaging closer to half a billion per flight.
Not cheap.
How frequent? 60 to 70 flights a year. The most it did in any single year was nine. 135 flights in all over three decades.
Not frequent.
OK, so how safe?
That's a little harder to answer, because when asked how safe something should be, most of us instinctively react with "zero fatalities, of course". After all, who wants to lose even a single life? But then, amateur philosophers like me point out that if zero fatalities was the bar, no one would fly or drive. After much bludgeoning by my club of reason, people grudgingly concede that some number of fatalities are to be expected.
It still does not answer the question. 
[Cue the flashback booth]
In 1986, following the tragic explosion of Challenger, an investigation followed. Many of you may remember the O-ring flaws that were highlighted in the media. Turns out that a famous scientist, Richard Feynman, in the report by the Rogers Commission concluded that the problems were far more serious. It appeared that NASA administration officials were playing--wait for it--a facsimile of Russian roulette. Feynman noted (see Appendix F)
NASA officials argue [that] "the probability of mission success is necessarily very close to 1.0." It is not very clear what this phrase means. Does it mean it is close to 1 or that it ought to be close to 1?"
NASA administration officials miscalculated or misrepresented the odds of failure. They boasted 1 in 100,000 failure rates. Which roughly meant that if the space shuttle flew every business day of the year for about half a millenium, you might expect a solitary mishap. Certainly most people would accept that, if those odds were realistically possible.
But were they? No, said the engineers and scientists actually working on the project. They quoted a much grimmer figure: 1 in 100. Even that was a tad optimistic according to Feynman, but he added that it was an achievable goal.

Ultimately, there were two catastrophic failures in the 135 flights. In fact, NASA recently reported that the early risk figures were about one in nine. Which means that the flights preceding Challenger were not safe by design, but by luck! Those odds are only slightly better than you'd have at Russian roulette.

Not safe.
An intern with some training could discern what a famous Nobel laureate concluded way back in 1986. That the Space Shuttle program was a failure. So why did NASA officials disregard their own engineers? My guess points to political pressure brought on by misplaced nationalism. We succumbed to our own propaganda. We trusted (and still trust) politicians, laymen, and shills more than scientists. We were and are No. 1, after all.
So why should you trust me? If you have been paying attention, you shouldn't. But I'd wager that if everyone verified for themselves, fewer than half of us would say ending the space shuttle program was a mistake.
Maybe one in six, or fewer.

1 comment:

Bretta said...

I was sorry to see it end but it was time for those particular vehicles to be retired.