Wednesday, February 16, 2011

The Space Shuttle Is Not Economical

The American physicist Gerard K. O'Neill wrote a book in the late '70s about how we could construct enormous rotating space colonies and launch a huge fleet of solar power satellites. He was imagining that the Space Shuttle would launch from 60 to 120 times a year, with a cost as low as $10 million per flight. As it turned out, we never launched more than 9 shuttles in one year and it ended up costing more like $500 million per launch. This cost is well over a billion dollars each flight if one considers program costs like the design, construction, and upgrading of the shuttles. How did we go from O'Neill's lofty vision to the current state where we're lucky to get four launches in a year?

Space Shuttle orbiter landing on runway
The stylish but expensive orbiter
Part of the problem is that NASA has tried to push the reliability of the shuttle to an extreme. To return to Earth successfully, the shuttle must get through the launch phase in pristine condition. Yet it is not placed at the safest spot of the bundle of rockets that carry it into space: the top. Instead it's attached to the side, in the path of debris falling off the external tank—the large red fuel tank in the center of the bundle. The shuttle's design is unnecessarily complicated and risky, and it's impractical to make this shuttle safer than a simpler capsule. NASA tries to, though, by spending a fortune tightening every bolt.

The shuttle is also notorious for launch delays. There are simply too many valves, sensors, and seals that can fail, and NASA won't launch if any of them do. This is to say nothing, of course, of the years the shuttles were completely grounded. They didn't fly for 975 days after the loss of Challenger, and 907 days after Columbia. We should consider the Space Shuttle's cost and schedule performance before committing to any similar launch scheme.

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