Reliability? It was the early mantra of the Space Agency that
components and systems must be not merely 99 percent reliable, but
99.999999999 percent. In other words, “out to nine nines,” as the
saying went. As we have learned, such approaches to perfection
reflect the earnestness of a program but are in many cases
impossible to reach and unprovable.
If something can go wrong, eventually it will. An inexorable
entropy beckons the very universe we live in. Whatever Einstein
thought about it, something is throwing dice somewhere.
The efficient cause of the Challenger accident was
easily pinned down. A faulty O-ring did not seal properly at
ignition of a solid booster, allowing a propellant burn-through
that eventually destroyed the central tank. Would it have happened
that way in warmer weather, with the ring consequently more
pliable? Maybe not. Had we seen hints of this before, in the
recovered solid casings? Maybe so. Were we out to nine nines on
this one? Maybe not.
The Columbia catastrophe is another case. Can foam
falling away during boost phase inflict fatal damage on a shuttle
wing? Or is this a false positive, leading all down a blind alley?
Did some other force cause the shuttle to start shedding tile when
it reached the sensible ocean of air we live at the bottom of, was
there damage from an exogenous source? Remember the cartoon
character who went around with a metal dome over his head, fearing
meteorites? He was living life out to many 9’s, taking no chances
of being victim to the first case of its kind. But he was not
fearing an impossibility.
Did the onboard computer guidance overreact? Was the craft
really doing what it sensed and what telemetry told the ground. If
an answer lies within the ken of man, he will find it, or reduce
the riddle to a few possibilities, one of which will eventually
become favored.
As it happens, President Bush has been promoting fuel cell
propulsion as an alternative to petroleum combustion engines these
days. It was a cell tank that exploded on Apollo 13’s outward bound
trip to the moon and required the subsequent lunar roundabout that
brought a harrowing but safe return. It is hydrogen and oxygen from
that big orange central tank that feeds the shuttle main engines as
they slip the surly bonds of Florida. There is chance in all.
Reducing the odds is everything.
I am reminded of a fateful interview with Robert Lusser, one of
Wernher von Braun’s compatriots from Germany who was a reliability
chief at Huntsville, where the rocket systems were being developed
in the early days. He told this reporter in an on-camera interview
in Texas in the mid-Fifties that the reliability requirements of
spaceflight were so stringent “that man can never go to the moon,
let alone to the Mars.” An honest judgment by a cautious man, but
one charged with helping make it happen. A few years later I asked
Dr. von Braun whatever happened to Dr. Lusser and he said with some
surprise at the question: “He returned to Germany.”
“Press on” is another phrase out of the astronaut lexicon. In
each of the eulogy speeches there is expressed that old
determination, to “press on.” It is sometimes buttressed by the
other arguments, the wealth of knowledge obtained by space
exploration, the gimcracks we have because of it, a desire to
somehow introduce a profit motive to refute those who in their
grief insist on asking why.
The more honest answer is because we can. We can live
the life imagined. And there is something here, in DNA,
that wants to go there.
Because we can.
