SSME Problems

I found an article actually praising the work done on the SSME and SRB's (That would be the Space Shuttle Main Engines and the Solid Rocket Boosters for those not nerdy enough). It's seems suspiciously like a few other articles I've read recently - all praising NASA for finding a faulty capacitor... Is it possible the buggers are all operating from the same set of NASA press releases?

Since the shuttle grounding, NASA SSME managers in Huntsville have been especially concerned that they not allow "process creep" to disarm flight safety, says Gene Goldman, engine project manager at Marshall. "This has been to assure ourselves that we are not getting into the 'normalization of deviance' that has been cited" as a key factor in the Columbia accident (AW&ST Apr. 28, 2003, p.29).

In manufacturing they set up rotations of line workers, so that no single employee does one job over and over again without end. By rotating people, they prevent injuries because everyone isn't over familiar with what they are working on, so they tend to be more cautious. I wonder why that wouldn't work at NASA... Problem solved. But I guess that would be too simple wouldn't it?

In any event this whole piece is a joke. Nowhere does it mention some of the problems that the External Tank fuel sensors had that did not receive the same level of testing as some said it should have. Maybe the ET is not considered to be officially part of the SSME system. Although for the life of me I can't understand why. Either way I find it disturbing that the author didn't mention this at all. He must have found this out in his research... Didn't he?

The SSMEs, unlike the solid boosters, involve extremely complex turbomachinery with thousands of parts, some rotating at nearly 40,000 rpm. And unlike the more massive SRBs, the liquid engines can be tested more frequently.

This is just weird. I don't know the author, so I don't want to claim that he was getting confused about the technical aspects of the shuttle, but there is one thing that makes no sense in that paragraph. At first he talks about the liquid rocket SSMEs. He correctly identifies them as having lots of moving parts and turbomachinery. Then he compares them to the SRBs and then says that the SSMEs can be tested more than the SRBs.

My initial thought is that I hope to crap that the SSMEs can be tested more than the SRBs. You light the SRBs, and it's done, it's over, it's finito. The SRBs are just solid rocket fuel stuffed into a shell. Light rocket fuel on fire and you try to stop a launch. How are you going to do a engine firing test of an SRB? That would be an interesting piece of science fiction.

The SSMEs are liquid rocket engines, that can be turned off and on. They can be controlled. Von Braun originally went with liquid rocket engines, throwing away the idea of SRBs, because of the issue of control. Von Braun was a good little engineer, and like a good little engineer, he values control above all else.

So I'd hope that the SSMEs can be tested more than the SRBs. That comment just seems a little... odd. It's not like he was wrong, but it seemed like the sentence was added in without a purpose. But then again who the crap am I to comment on other people's strange grammar. If you've read this far - you're probably laughing at the spelling of an Engineer.

Either way they are really pushing this whole isse about how they're rigorous testing found a faulty capacitor on the shuttle and replaced it - showing of course how "rigorous" and "detailed" the testing was.

Propulsion safety requires rigorous pre-launch testing and quality control, which earlier found a manufacturing flaw in Honeywell electronic capacitors for the critical SSME engine controller (AW&ST June 27, p. 22).

Gee whiz. Well I guess the Shuttle is safe afterall. Me and my silly worrying. Look they actually found a capacitor problem that was on the shuttle probably for years. Well don't I look stupid now.

After all, the shuttle has been "rigorously" tested, and is safe now. Good to know. But I won't be boarding anytime soon.