Monday, June 8, 2009

Monte Hall's Revenge

The Italian Waiter should have been in his element at the three day spaghetti fest at the Ames Research Center last week. He had hoped to back fill his previously unfulfilled claim of multiple paths to thrust oscillation resolution. You'll recall that the Emperor, in turn, proclaimed the all clear loudly to the New York Times back in February 2008.

It seems the pasta in this recipe is not yet al dente. No chef worth his salt would stand behind any of the solutions presented. And like Gordon Ramsey, our soon-to-be Olive Garden intern would hear none of it and stormed out on the second day of the fest without his blue ribbon.

First up for review was the preferred solution of a single plane attenuation system. It was believed to be the lightest weight band-aid available for the already overweight and underperforming stick. Architectural changes made to the segmented spaghetti-like stack have made it stiffer. That had the unfortunate side-effect of sending increased loads up to the crew compartment. Those loads are even higher than the seat-of-the-pants requirements loosened by fiat (and loosey-goosey analysis) from the accepted Gemini era 0.25 g peak to almost three times that value (0.7 g).

Scratch the goateed one's favorite solution.

Next up in the course of two day's worth of testy discussions was the dual plane attenuation solution. Substitute titanium for aluminum to make it lighter, but as goes the single plane solution, so maybe goes the dual plane, but with more weight nonetheless. And, oh by the way, its still way too early in the analysis cycle to know anything for sure, since a certain program manager was more or less putting all his chips on the first horse.

What's behind door number three?

How about a TRL 3 upper stage LOX tank baffle? Just imagine the poor engineers who will have to try and balance propellant depletion against stick oscillation as the tone changes going uphill. Repeatability? Just a nuisance the supercomputers can make go away. Varying mission profiles (remember the rolly one trying to sell Ares-1 as a multi-purpose launch vehicle)? Good luck.

Its enough to make even a faux program manager pas.


Anonymous said...

The Ares 1 has more problems than you can shake a stick at........ 8^}

Anonymous said...

Hmm... I'd imagine that the upper stage LOX flow rate during first-stage ascent should be the same no matter the trajectory. As in zero. Can't argue with the TRL 3, though.

Anonymous said...

Take this any way you want, but every time I read one of your posts,(and I've read every one) I feel ill...

Anonymous said...

Remember: When Monte Hall shows you a goat (or goateed one) behind one of the doors, you should always switch... statistically speaking.

Anonymous said...

Nothing was mentioned about upper stage lox flow - rather the statement was that the lox levels affect the tone of the oscillation too and trying to optimize them when the stage itself is TRL3 is difficult to say the least.