Ares Woes Ongoing

There seem to be some problems with your formatting. Probably the new system.

Rand

Every solid rocket that I have ever flown a payload on has these problems and it is no surprise that the SRB has them in spades. If you look at NASA video of the crew during the SRB burn you can see these low frequency oscillations on the crew. Now with the damping inside the ET it is of a much lower amplitude but it is still there. I have flown accelerometers on the Shuttle and it would be fairly trivial to fly a set in the crew compartment, cargo bay, and even on the SRB's (you don't have to put them on the inside of the booster) to get an idea of the frequency. There will probably be some dispersion of the signal due to the fact that you have two boosters that operate at not exactly the same frequency that will add a spread function to the signal so you probably need to instrument both boosters to get a handle on this to take it out of the final model.

This is anything but a trivial problem and for MIke to be dismissive does not bode well.

Yes, it seems to be weirding out on quote marks. I'll have to look at encoding.

NASA is in a major panic over this issue. All of the proposed solutions cost mass, lots of it.

Looks like an open bold tag.

Also, I think that your default character encoding changed from ISO-8859-1 to UTF-8 -- not that there's anything wrong with that.

Looks like an open bold tag.

Also, I think that your default character encoding changed from ISO-8859-1 to UTF-8 -- not that there's anything wrong with that.

If I read it correctly the flight test they want to do won't take place until 2009. Nice....keep plugging away, and spending money of course, on something that you'll find out won't work. Sounds like NASA.

Cheezy

Yea I read that but there is really no reason not to fly accelerometers at least in a Mid Deck locker to get data.

Heck I have a qualified set right now that they could use that have already flown multiple times.

Rand is using selective quotes to make the problem seem more severe than it actually is. Here's something he neglected to point out in the article:

"But the focus team has since calculated that the problem may not be as severe as originally feared. Nominally the oscillation frequency of a five-segment booster is 12 Hz. (compared with 15 Hz. for the four-segment version). But after that it gets complicated. Translating RSRM ground-test data into accurate forcing function figures and the stack’s response to that force is extremely difficult, particularly since the upper-stage and Orion designs remain immature and oscillation data are based on ground tests.

"Lyles says oscillation may not be as well-organized—and destructive—as feared, and may even be random instead of a steady wave that can resonate with the rest of the vehicle. And even if it isn’t, the vehicle response may not be as severe as possible. The shuttle stack is “insensitive” to the frequencies generated by its four-segment boosters, and because of the timing of the oscillations the Ares I structure may already be robust enough to handle the most serious loads. That would limit needed fixes to subsystems, which should be easier."

So it looks like the oscillation problem is just one of the standard teething difficuties inherent in any new design and not, as apparently the Internet Rocketeer Club seems to hope (speaking of not having a plan), a complete disaster that will sink the entire program.

Mark, you ignore all the "mays" in those quotes in which you take so much misguided comfort. But then, not being a member of your mythical "Internet Rocketeer Club," perhaps you just don't understand the implications.

"So it looks like the oscillation problem is just one of the standard teething difficuties inherent in any new design"

If Shittington had an ounce of aerospace engineering education or experience, he wouldn't have to deduce that "it looks like" every rocket has acoustic issues -- he'd know it.

And Shittington would also know that these issues come in different flavors -- POGO, resonant burn, etc.

And Shittington would know that the "average 4.3g" forces mentioned in the article means that Ares I's solid motor first-stage will induce transient forces in the 8-10g range, at the limits of human endurance and imposing large mass penalties to shield the systems on the upper stage and Orion.

And Shittington would know that the mass margins on the upper stage and Orion are already stretched thin, with no redundancy on some subsystems and no ability to absorb such huge mass penalties without completely rethinking Orion's size and requirements.

But no, Shittington has no such education or experience, so he grasps at second-hand straws and punctuation in a non-technical article to hold onto poorly conceived and ill-informed opinions.

"and not, as apparently the Internet Rocketeer Club"

And what exactly are Shittington's aerospace engineering analysis credentials? A (suppossed) bachelor's degree in history? Rejection letters from the publishing houses that wouldn't print his lousy science fiction novels? Self-published masturbatory dittohead editorials? Weird, pedophilic reviews of Harry Potter books and movies?

Shittington should stop throwing rocks through his glass house at persons with actual, relevant expertise to bear on subjects relating to NASA and space.

"So it looks like the oscillation problem is just one of the standard teething difficuties inherent in any new design"

If Shittington had an ounce of aerospace engineering education or experience, he wouldn't have to deduce that "it looks like" every rocket has acoustic issues -- he'd know it.

And Shittington would also know that these issues come in different flavors -- POGO, resonant burn, etc.

And Shittington would know that the "average 4.3g" forces mentioned in the article means that Ares I's solid motor first-stage will induce transient forces in the 8-10g range, at the limits of human endurance and imposing large mass penalties to shield the systems on the upper stage and Orion.

And Shittington would know that the mass margins on the upper stage and Orion are already stretched thin, with no redundancy on some subsystems and no ability to absorb such huge mass penalties without completely rethinking Orion's size and requirements.

But no, Shittington has no such education or experience, so he grasps at second-hand straws and punctuation in a non-technical article to hold onto poorly conceived and ill-informed opinions.

"and not, as apparently the Internet Rocketeer Club"

And what exactly are Shittington's aerospace engineering analysis credentials? A (suppossed) bachelor's degree in history? Rejection letters from the publishing houses that wouldn't print his lousy science fiction novels? Self-published masturbatory dittohead editorials? Weird, pedophilic reviews of Harry Potter books and movies?

Shittington should stop throwing rocks through his glass house at persons with actual, relevant expertise to bear on subjects relating to NASA and space.

And what exactly are Shittington's aerospace engineering analysis credentials? A (suppossed) bachelor's degree in history?

You mean besides co-founding the "Clear Lake Group" with noted fighter pilot/Navy SEAL/satellite expert/Annapolis professor/Apollo astronaut/secret agent Robert Oler?

What other credentials could you possibly need, when you've been the sidekick to a superhero? :-)

Does anyone read Mark's blog?

The noted "space policy analyst" now has a story about how if Nixon hadn't cancelled Apollo, NASA would have discovered a cure for Alzheimer's!

Because they would have a cool space station to do medical research.

Oh, wait a minute. NASA does have a space station to do medical research -- and they haven't discovered a cure for Alzheimer's.

What a maroon.

Does anyone read Mark's blog?

The noted "space policy analyst" now has a story about how if Nixon hadn't cancelled Apollo, NASA would have discovered a cure for Alzheimer's!

Because they would have a cool space station to do medical research.

Oh, wait a minute. NASA does have a space station to do medical research -- and they haven't discovered a cure for Alzheimer's.

What a maroon.

Maroon = chestnut color

Moron = those that misspell moron

3rd-

Check your Bugs Bunny lore. Maroon is the way he pronounced moron.