Sunday, February 13, 2011

Study: NASA Underestimated Shuttle Dangers


STS-1 Columbia launches on April 12, 1981. A new study estimates there was a 1-in-9 chance of a catastrophic event during the mission.

Florida Today reports that NASA underestimated the dangers inherent in the Shuttle design, especially in its early years.

At the time, managers thought there was only a 1-in-100,000 chance of losing a shuttle and its crew. Engineers thought the probability was closer to 1 in 100. But in reality, the odds of a disaster were much higher.

On each of the shuttle's first nine missions, there was a 1 in 9 chance of a catastrophic accident, according to the new risk analysis. On the next 16 flights that led up to and included the January 1986 Challenger disaster, the odds were 1 in 10.


A sidebar lists some of the "close calls," including one in 1998 when John Glenn was aboard. "The drag chute door on the tail of the shuttle fell off at liftoff, striking one of the orbiter's three main engines and creating a breach in the thermal protection system that protects shuttle astronauts during atmospheric re-entry."

I've written many articles here explaining why the Bush administration cancelled the Space Shuttle program in January 2004. Shuttle's fundamental design flaw is that the crew vehicle is mounted on the side of the fuel tank, increasing the risk of exposure to flame (STS-51L Challenger) and falling debris (STS-107 Columbia).

The Bush administration, in response to the findings by the Columbia Accident Investigation Board, directed that Shuttle be retired once International Space Station construction is completed, and contracted with Russia to fly U.S. astronauts on Soyuz spacecraft whenever possible as it was deemed a safer system. A front-page article in the January 30, 2004 Florida Today stated, "Some U.S. astronauts, including current space station commander Michael Foale, said they prefer flying on the Soyuz because it has a crew escape system not present on the shuttles."

United Space Alliance recently proposed extending Shuttle through the Commercial Crew and Cargo program. A USA executive said, "It is safe. We have a lot of history, we understand how to operate it."

The evidence is overwhelmingly clear that it is not safe, and this new internal risk assessment is further proof.

We can debate which proposal should be selected as the next-generation vehicle for American human space flight. But the debate over extending Shuttle should end once and for all.

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