Tuesday, November 4, 2014

Why we shouldn't be frightened by the Virgin Galactic accident

The BBC just published an article about the recent, fatal crash of Virgin Galactic's SpaceShipTwo during a test flight over the Mojave. The article, entitled "How safe can we really make space for future tourists?" does a rather superficial job of answering its own question, briefly citing the few major space shuttle and other orbiter disasters from the Space Age up into the nineties.

The problem with this analysis is that it does not, in the slightest, take into account the nature of the Virgin Galactic accident itself - an obvious move, one might think, if the author seeks to use this accident as a jumping-off point for a discussion of modern space travel, rather than the failures of older generations of technology.

So, let's pick up on that point: what caused the accident? Virgin Galactic's statement refuses to offer an official explanation by this early date, but the released information increasingly points to human error. From the statement:

The NTSB also evaluated the vehicle’s feathering mechanism, which is the unique technology that turns the wing booms into position for re-entry. The NTSB indicated that the lock/unlock lever was pulled prematurely based on recorded speed at the time, and they have suggested that subsequent aerodynamic forces then deployed the feathering mechanism, which resulted in the in-flight separation of the wings and vehicle.

Basically, one of SpaceShipTwo's pilots unlocked a "feathering" (read: braking) mechanism at high speed, and given what this seems to have done to the plane, this sounds like the equivalent of sharply yanking the steering wheel in a car doing eighty miles per hour.

While the accident is truly unfortunate, this is somewhat reassuring: an operator error caused the craft to break up, not a materials failure. Human error is universal to the operation of any machinery; for this we need look no farther than traffic deaths in the United States, which occur several times a day even without the presence of drunk driving. Humans make mistakes; this is a simple fact of reality.

This is reassuring because, if such an error turns out to be the cause of the accident, then the advanced technology available to developers of space travel vessels can actually protect against future repeats. (Maybe an automatic, speed-sensitive safety device could prevent the feathering mechanism from unlocking at high speeds - the way some cars automatically lock their doors while the vehicle is in motion.)

So, is space travel inherently more dangerous than any other, human-operated mode of mechanized travel? No. Risk of human error pervades all of our activity. The true question will be how the private space industry responds to challenges such as this.

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