The Winds of Change
With the release of the Columbia Accident Investigation Board's report, the furor has begun and the debate over the next great sea change in NASA policy is underway. But out of all the editorializing and bomb-throwing, one voice in particular stands out for its articulation of that rare commodity: exceptionally clear thinking.
Homer Hickam is a former NASA engineer and current speaker/writer with an inspirational personal story that you may recall (in slightly idealized form) from the movie October Sky, based on his autobiographical book Rocket Boys. At present, he is also spelling out in no uncertain terms what the real problems in NASA are, regardless of how the CAIB hedges its bets and treads political water, and is explaining the solutions. http://www.spaceref.com/news/viewnews.ht... In a just world, the powers-that-be would heed his suggestions.
His most compelling analogy is one that I had not seen before, and now wish I could take credit for myself: the space shuttle as Vietnam. The vehicle's design was driven in contradictory directions by multiple and conflicting mission requirements; its operation has consumed billions of dollars and decades of effort with relatively little to show for it in terms of the long-term goal that the program build the infrastructure for pursuit of larger objectives. The space shuttle has failed economically (remember the promise of getting people and cargo into space dozens of times each year, for a tenth of the going rate?); the space station it was supposed to construct and support is more than a decade late, over budget, and incomplete; and we have now lost two orbiters and crews. And fundamental design problems that were forced by early demands and cannot be solved within the constraints of the shuttle architecture now stand ready to consume vastly greater sums of money and spans of time, to no avail.
A camel is a horse designed by a committee; some maneuvers early in the shuttle design process determined that this particular camel would not even have a hump. Hickam traces the decisions involved quite clearly. Ideally, the shuttle would sit on top of the rest of the stack, not hang off the back. In the top position (which will be used for the Orbital Space Plane, mark my words) the Columbia would not have sustained damage from falling foam, and the Challenger could potentially have weathered the explosion and glided back. So why wasn't that position-the logical, obvious one for many reasons-the one implemented? Because the engines were going to be reused, which meant being attached to the orbiter, and yet they also had to be at the bottom of the stack. Now, it turns out that this was definitely not a money-saver, which was the whole point, so there's no real debate over how to launch the Orbital Space Plane. It will fly to orbit atop man-rated expendables. But in the meantime, the space shuttle still has a crucial, architectural feature that severely constrains its safety, and that cannot really be fixed. Putting the astronauts in the most dangerous possible location during launch is extremely dangerous no matter how you redesign the tank foam, and as long as the shuttle flies, that is exactly where they will be.
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