Have a Backup Plan

The quickest way to separate the rocket scientists from the non-rocket scientists is to check out their backup plan. All you have to do is ask, "So what's Plan B?"

Space travel is so difficult and dangerous that there have to be doubly and triply redundant systems to beat back catastrophic errors and to maintain a level of safety. Rockets have a nasty habit of exploding—after all, 90 percent of their weight is composed of highly combustible propellant. They are for all practical purposes flying bombs. (But that's what makes rocket science so interesting.)

In the beginning, our flying bombs did what you'd expect them to do—they exploded half the time. Then, after some experience, our rocket scientists got them to explode only 10 percent of the time, which was cause for great celebration and jubilant merrymaking. Today, after a half century, even our best rockets still blow up about 2 percent of the time. That's one out of every fifty flights.

The average launch vehicle costs about $500 million and the average communication satellite is worth nearly a billion dollars. If it were possible to keep our rockets from exploding 2 percent of the time, we would have figured that out a long time ago because the economic incentive is tremendous. (We might even say "astronomical.")

Rocket scientists realized in the beginning that for human missions, we would have to employ escape systems to save the lives of the astronauts in the event of a launch mishap. An escape tower was attached to the top of the Mercury capsule that would pluck the capsule off the top of the launch vehicle, carry the astronaut thousands of feet above the exploding rocket, and then deploy parachutes to ensure a safe landing. A similar system was used on the three-man Apollo capsule; an ejection system was used on the two-man Gemini.

Unfortunately, many of these lessons were forgotten or ignored in the shuttle program, which is why seven astronauts were killed in 1986 in the Challenger launch. The booster exploded seventy-three seconds after launch and the astronauts did not eject nor did they use an escape tower—because they didn't have ejection seats or an escape tower. These backup systems were deemed too heavy to include in the shuttle, which was supposed to, according to NASA, have a 1 in 100,000 chance of failing during launch.

Nobel laureate Richard Feynman compared shuttle flights to "playing Russian roulette . . . you pull the trigger and the gun doesn't go off, so it must be safe to pull the trigger again. . . ." (For a detailed account, see Feynman's brilliant book What Do You Care What Other People Think?In Part 2, "Mr. Feynman Goes to Washington: Investigating the Space Shuttle Challenger Disaster," he tells the story as no one else can.)

The bottom line is that after performing the greatest technological feat in the history of the human race—landing men on the moon—NASA stopped thinking like rocket scientists and built the shuttle.

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