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Some folks have been criticizing the recent Orion parachute test failure as just one more screwup at NASA that they've been covering up, and made a bigger deal of it than it is, but Henry Spencer has a more nuanced, and correct view:

Foul-ups in testing are not uncommon, especially when the test setup is being tried for the first time. One of the headaches of high-tech test programmes is having to debug the test arrangements before you can start debugging the things you're trying to test.

Sometimes a malfunctioning test setup actually gives the tested system a chance to show what it can do in an unrehearsed emergency. During a test of an Apollo escape-system in the 1960s, the escape system successfully got the capsule clear of a malfunctioning test rocket.

But sometimes the test conditions are so unrealistically severe that there's no hope of correct functioning. Unpleasant though the result often looks, this isn't properly considered a failure of the tested system. That seems to have been what happened here.

As I've noted before, requirements verification is where the real cost of a development program comes from, particularly when the only useful verification method is test.


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anon in tx wrote:

no, it was a screw up. the drop shape was not stable and analysis suggested that there was around a 40% chance that the test would fail because of the instability, which is what happened. There was not enough time to correct the problem without slipping the schedule.

mpthompson wrote:

There was not enough time to correct the problem without slipping the schedule.

Hmmm, do you are saying is NASA thought there wasn't enough time to do it right, but thanks to the failure there is enough time to do it twice (or more). Sad.

Mark Michael wrote:

Man-rating often involves testing something until it breaks. When it breaks, it doesn't look pretty. But, it provides some sense of the outer edges of the performance and safety envelopes to the folks who have to make real-time decisions when there is someone on-board other than a crash dummy. Living in a visual age, we often forget that, except for the engineers.

Of course, some of us are engineers so that we can watch stuff blow up. Just like SEALs often join because they like to do the blowing-up themselves ... :-)

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This page contains a single entry by Rand Simberg published on August 20, 2008 3:52 PM.

Interesting Rumor was the previous entry in this blog.

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