“Rocketman” has thoughts related to yesterday’s post, here, and more details on last week’s Ames meeting:

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.

I know it’s popular and easy for some who don’t understand physics and engineering to say, “well we had problems on program X, and we managed to solve them,” without understanding that there are some technical problems that simply have no solution, regardless of how much time and money is put into them. Sometimes, all the potential solutions simply introduce new problems, or make the old ones worse, and you end up chasing your tail and failing to get the design to close. I don’t know if the Ares thrust-oscillation problem falls in that category, but the possibility cannot be excluded, and so far, it’s looking that way. And when that happens, the only solution is to go back to the drawing board, and start with a different concept.

A good engineer will recognize such problems early, and not waste too much time and money trying to solve them. As Einstein once said, a clever man will solve a problem — a wise man will avoid it. We had, and still have, at least for now, people running NASA’s human spaceflight development program who (as the Brits would say) are too clever by half.

Rocketman also thinks that the writing is on the wall:

All hailed and praised the rocket scientist with more degrees than fingers on our right hands. As the Kool-Aid flowed, we reveled in the plans to renew the minions’ skills for building cathedrals to the sky. We marveled at the safety numbers that flew out of the supercomputers. And we ignored the mounting number of little things that were “normal for a development program.” The steroids flowed, the oscillations increased, and the dollars disappeared.

Fast forward five years with nothing to show for the investments made so far. “Wait a little longer,” they say. “We’re getting our arms around this.” And the congressfolk from Florida push for more money to shower over the falls. And the Senator from Alabama holds up any investments in commercial opportunities so that his precious voters will hold on to their jobs.

But it is already too late. Indeed, the seal on the codex has been broken. All the President’s men do not carry rose colored glasses around with them. They see the forest for the trees.

Clark Lindsey has a summary of a Space News editorial by Bob Bigelow, that would appear to be explaining what should have been obvious to the Senator from Huntsville (who is also the Senator from Decatur, so I continue to be baffled why he doesn’t want to ramp up EELV production).

/– Talks about the overruns in Constellation
/– “Constellation appears to be yet another ill-conceived NASA boondoggle suffering from all too familiar runaway costs.”
/– Talks about the serious technical problems with Ares/Orion
/– Criticizes the reduction of Orion from 6 to 4 passengers.
/– Gives a vigorous defense of the accomplishments of SpaceX and its potential to provide low cost launch access.
/– Says Shelby made an error in ignoring the commercial access capabilities of the Atlas V, which is produced in Alabama.
/– “Bigelow Aerospace has studied human-rating of the Atlas 5 and found the concept to be both viable and economically attractive.”
/– The high reliability of the Atlas V undercuts Shelby’s comments about commercial launchers.
/– “Commercial crew transport, as demonstrated by SpaceX’s dramatic progress and the existing Atlas 5 launcher, represents a viable, affordable, and robust path forward.”
/– Talks about the many launch vehicle project failures at NASA.
/– “Moreover, to hear a Republican senator espouse the virtues of a bloated, costly government program over innovative commercial concepts is so paradoxical that it requires no further comment from me.”

Hey, since when did Republicans care about business, or markets? Not when it doesn’t suit their parochial political interests, for sure.

Norm Augustine and his panel have quite the challenge ahead of them.

No one who has been following the program will be shocked to learn that the major, fundamental design issues continue, and that they aren’t just “teething pains” of a new program. Despite a lot of happy talk from Griffin and Cook and Hanley over the past few months, thrust oscillation remains a serious problem for the Ares I first stage:

According to a NASA blog, the engineers are still looking at putting a series of passive dampers at the bottom of the rocket and a series of spring-like brackets in the middle to soak up the vibrations like shock absorbers.

Originally the brackets, called a dual plane C-spring isolator system, were too heavy to incorporate into the overall design. An updated version uses titanium, which is as strong as steel but lighter.

However, the fixes are not easy and engineers have yet to settle on a solution. According to NASA officials who attended the meeting, the shaking problem is more difficult to combat than originally thought as each solid rocket burns slightly differently.

You don’t say. That means that a passive solution won’t work, unless they can predict prior to flight exactly what the characteristics will be for each SRB (a longer way of saying…it won’t work). They’ll have to have an active approach that can actually measure the vibrations in real time and try to compensate for them. My solution? Bag the solid first stage. Here’s one that will save even more money. Bag Ares I.

And all is not well at the pointy end of the rocket, either:

An Air Force memo obtained by Todd Halvorson of Florida Today indicates that military safety officials are worried that NASA’s Orion capsule and its crew might not survive an emergency escape off an exploding Ares I rocket.

As I understand it, the concern is that the launch abort system is sized to accelerate away from an exploding upper stage, and to outrun an out-of-control first stage, but not from the flack created by the massive explosion of an SRB. Parenthetically (without the parentheses) it should be noted that one of the ways that NASA put its thumb on the scales when it compared Ares to EELV was to assume that the same LAS would be used in both cases, but the latter has a much more benign failure environment, and could get by with a much lighter LAS, so dinging the EELV for lacking the performance to lift an unnecessary weight was stacking the deck against it.

Anyway, how likely is it that the first stage will explode? Well, I find this sadly amusing:

…the article also has Hanley pooh-poohing the Air Force’s concerns, saying that “supercomputer analyses” will prove that the Ares I rocket is a fine vehicle and Orion’s launch abort system will be able to save the crew in the event disaster strikes.

They have top men looking at it. Who?

Top. Men.

Here’s my question. If they know the results of the “supercomputer analyses” before they have performed them, why are they bothering to perform them? Couldn’t they save some money and just skip them?

Florida Today quotes Hanley saying that the statistical probability of an Ares I first-stage failure is remote. He pinpointed it at 1 in 3,000 to 1 in 3,500.

Gotta love that verb, “pinpointed.”

You know, those were the kinds of numbers that they were claiming for Shuttle, right up until around January 27th, 1986. They got some new data the next day, though, that significantly altered the estimates going forward…

So, once again, show us the numbers, Jeff. Show us your work.

It’s hard to know from this brief news story, so I don’t even know what he means by “failure.” Does he mean spontaneously explode without warning? Well, it’s not unheard of for solid rocket motors to do just that, though it has never occurred in the Shuttle program. But I suspect that what the Air Force is concerned about is a different kind of failure — a guidance failure that requires the Range Safety Officer to destroy the vehicle so that it doesn’t hit any uninvolved areas (e.g., Daytona). And considering that an SRB has never had to do guidance without help from a partner on the other side of the tanks and the SSME gimbals, that’s a non-trivial concern. And when the stage is destroyed (by setting off a linear charge along its length) it could create explosive debris that the LAS may not outrun. I assume that’s the Air Force’s (probably supported by an analysis from Aerospace) concern.

Of course, this all raises the question of whether or not we should even have a launch abort system, as I’ve discussed previously, with further thoughts here. Of course, the whole problem goes back to NASA’s “cargo-cult” engineering approach to Constellation, in which they think that if they just go back and do things the way the Apollo gods did, except “on steroids,” they’ll once again have a successful program.