Thrust Oscillation Issue Threatens Ares I Design, Aviation Week

bob haller safety advocate wrote:
On Feb 2, 1:12�pm, kT wrote:
Michael Gallagher wrote:
On the other hand, the guys at NASA were the ones who found the
problem in the first place.
That's ridiculous, the entire physics community knew about this problem
from day 1. We didn't think anybody was dumb enough to actually try it.

After late September of 2005, I ran a blog which clearly pointed out
these problems, surely you must remember it. You did read it, right?

http://cosmic.lifeform.org (offline)

I guess you didn't read it.

is it possible nasa intentially chose a design they knew wouldnt work?

It's well known that they are hostile to civilian space flight.

You figure it out.

The real reason for not being too bothered if it worked or not was that the
President will be different well before any flight and nobody wants to waste
too much money.

Contrast the dodgy way the design was chosen with the efforts being put
into the Shuttle and station fixes. I think they know that these quests for
knowledge and their outcomes will be worth more for whatever comes next in
the new administration.

Kind of generic reliability concerns etc.

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
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"bob haller safety advocate" wrote in message
...
On Feb 2, 1:12?pm, kT wrote:
Michael Gallagher wrote:
On the other hand, the guys at NASA were the ones who found the
problem in the first place.

That's ridiculous, the entire physics community knew about this problem
from day 1. We didn't think anybody was dumb enough to actually try it.

After late September of 2005, I ran a blog which clearly pointed out
these problems, surely you must remember it. You did read it, right?

http://cosmic.lifeform.org(offline)

I guess you didn't read it.

is it possible nasa intentially chose a design they knew wouldnt work?
just to keep the shuttle flying longer..........

On Feb 3, 3:38�am, "Brian Gaff" wrote:
The �real reason for not being too bothered if it worked or not was that the
President will be different well before any flight and nobody wants to waste
too much money.

Contrast the �dodgy way the design was chosen with the efforts being put
into the Shuttle and station fixes. I think they know that these quests for
knowledge and their �outcomes will be worth more �for whatever comes next in
the new administration.

Kind of �generic reliability concerns etc.

Brian

nASA worried about wasting money? lets get real.

between paying off existing contractors,not wanting to use
expendables, the entire process is flawed, and the next president
might kill man in space.

I would support that provided 100% of the savings went in robotic
missions, and a small devlopment effort for future manned space
explorations.

this would give private industry time to make their mark.

On the other hand, the guys at NASA were the ones who found the
problem in the first place.



Is this similar to the pogo problem the early Saturn rockets had?

In any event, the best time to find big problems is early, before time
and effort and money is spent.

"robert casey" wrote in message
...


On the other hand, the guys at NASA were the ones who found the
problem in the first place.



Is this similar to the pogo problem the early Saturn rockets had?

Not really. Saturns had liquid fueled engines so the pogo problem could be
solved relatively easily. The thrust oscillation issue with large solid
rocket boosters is an entirely different problem.

In any event, the best time to find big problems is early, before time and
effort and money is spent.

While true, some problems can't be solved. One thing that Ares I doesn't
have is a lot of margin to throw mass at a problem like this. Orion is
pretty much at the limits of what Ares I can launch, so any changes needed
to solve this problem had better have little impact to the mass of Ares I.
With large vibration type problems, quite a bit of mass is sometimes what
you need to throw at the problem.

Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein

"Jeff Findley" wrote in message
...

"robert casey" wrote in message
...


On the other hand, the guys at NASA were the ones who found the
problem in the first place.



Is this similar to the pogo problem the early Saturn rockets had?

Not really. Saturns had liquid fueled engines so the pogo problem could
be solved relatively easily. The thrust oscillation issue with large
solid rocket boosters is an entirely different problem.

In any event, the best time to find big problems is early, before time
and effort and money is spent.

While true, some problems can't be solved. One thing that Ares I doesn't
have is a lot of margin to throw mass at a problem like this. Orion is
pretty much at the limits of what Ares I can launch, so any changes
needed to solve this problem had better have little impact to the mass of
Ares I. With large vibration type problems, quite a bit of mass is
sometimes what you need to throw at the problem.

Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein

I'm certainly not a rocket scientist by any stretch, but it would appear
that some type of dampening needs to occur between the solid rocket motors
and the Orion. Can this be accomplished by placing the Orion in some kind
of dampening skid, possiibly made of vulcanized rubber? It might even
solve the problem of what to do with all those defective Firestone tires.
:-)

George

On Sat, 02 Feb 2008 13:07:22 -0500, in a place far, far away, Michael
Gallagher made the phosphor on my monitor glow
in such a way as to indicate that:

What scares me the most about this is that NASA will likely keep plowing
ahead with Ares I and Orion without understanding how bad this problem will
be .....

On the other hand, the guys at NASA were the ones who found the
problem in the first place. If they are competent enough to identify
the problem years before the first Ares 1 flies, might they not be
competent enough to fix it in time?

They might. Then again, they might not. This is called "program
risk."

..... In other words, NASA could spend billions developing Ares I only to find out
late in the game that it's fatally flawed, or not.


Or maybe, just maybe, against all probabilty, they could do the
impossible ... and fix it. Stranger things have happened.

Do you discount the possibility that it is indeed impossible, that
there is no fix? If so, why? They can't repeal the laws of physics.

On Sat, 02 Feb 2008 18:37:05 GMT, h (Rand
Simberg) wrote:

Do you discount the possibility that it is indeed impossible, that
there is no fix? If so, why? They can't repeal the laws of physics.

I don't discount the possiblity that it can't be fixed, but I don't
consider it a certainty it can't be fixed. Unless someone has already
tried to build a man-rated rocket with a five segment SRB as a first
stage and a cryogenice upper stage, then there is no emperical
evidence about the vibrations for a working launcher. The only thing
we have is the same thing NASA has -- computer simulations that say
there might be a problem 1:40 into the first stage burn. First, they
have to figure out how accurate that model is and whether the problem
will be that bad. Then they have to look at that fixes, which the
article cited by the first poster mention; they haven't been sitting
on their hands, have they? And only a time traveler could say for
certain whether the fixes will work or not. The rest is arm-chair
quaterbacking.

If they vibration can't be fixed, so what? They'll still want the
five-segment SRB for the Ares V, so that will stay in development.
They could probably build Ares 1 with a liquid first stage powered by
RS-68 engines, so they can mainatane the technical continuity between
1 and V. But that assumes it can't be fixed, and because (A) I am not
a time traveler from 2015 who knows what happened; (B) haven't already
tried to build Ares 1 on my own and found out what happened; or (C)
don't have a supercomputer better than NASA's that makes infallible
simulations, I do not know what will happen with that. Maybe they'll
fix it; maybe they won't. But that is a long way from predicting they
won't as if that's an accomplished fact.



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Michael Gallagher wrote:
On Sat, 02 Feb 2008 18:37:05 GMT, h (Rand
Simberg) wrote:

Do you discount the possibility that it is indeed impossible, that
there is no fix? If so, why? They can't repeal the laws of physics.

I don't discount the possiblity that it can't be fixed, but I don't
consider it a certainty it can't be fixed. Unless someone has already
tried to build a man-rated rocket with a five segment SRB as a first
stage and a cryogenice upper stage, then there is no emperical
evidence about the vibrations for a working launcher. The only thing
we have is the same thing NASA has -- computer simulations that say
there might be a problem 1:40 into the first stage burn. First, they
have to figure out how accurate that model is and whether the problem
will be that bad. Then they have to look at that fixes, which the
article cited by the first poster mention; they haven't been sitting
on their hands, have they? And only a time traveler could say for
certain whether the fixes will work or not. The rest is arm-chair
quaterbacking.

If they vibration can't be fixed, so what? They'll still want the
five-segment SRB for the Ares V, so that will stay in development.
They could probably build Ares 1 with a liquid first stage powered by
RS-68 engines, so they can mainatane the technical continuity between
1 and V. But that assumes it can't be fixed, and because (A) I am not
a time traveler from 2015 who knows what happened; (B) haven't already
tried to build Ares 1 on my own and found out what happened; or (C)
don't have a supercomputer better than NASA's that makes infallible
simulations, I do not know what will happen with that. Maybe they'll
fix it; maybe they won't. But that is a long way from predicting they
won't as if that's an accomplished fact.

It isn't worth fixing, and by pursuing this irrational path they have
ruined any chance they had for expendable heavy lift launch vehicles.

Not that it would be a bad thing if expendable heavy lift were canceled,
but I was kind of looking forward to that ten meter tankage for my
really gigantic reusable rocket ships, somewhere down the line.

Unless NASA really shifts gears on this, and I have provided them with
an excellent opportunity, and an excellent method of doing just that :

http://webpages.charter.net/tsiolkov...oposal/IPO.doc

This is the only way they can salvage their heavy lift.

On Tue, 05 Feb 2008 13:00:39 -0500, in a place far, far away, Michael
Gallagher made the phosphor on my monitor glow
in such a way as to indicate that:

On Sat, 02 Feb 2008 18:37:05 GMT, h (Rand
Simberg) wrote:

Do you discount the possibility that it is indeed impossible, that
there is no fix? If so, why? They can't repeal the laws of physics.

I don't discount the possiblity that it can't be fixed, but I don't
consider it a certainty it can't be fixed.

No, just a high probability.

Unless someone has already
tried to build a man-rated rocket with a five segment SRB as a first
stage and a cryogenice upper stage, then there is no emperical
evidence about the vibrations for a working launcher.

Getting empirical data may be very costly, and it may only tell you
what may think the analysis is already showing.

The only thing
we have is the same thing NASA has -- computer simulations that say
there might be a problem 1:40 into the first stage burn. First, they
have to figure out how accurate that model is and whether the problem
will be that bad. Then they have to look at that fixes, which the
article cited by the first poster mention; they haven't been sitting
on their hands, have they? And only a time traveler could say for
certain whether the fixes will work or not. The rest is arm-chair
quaterbacking.

One of the jobs of a manager is to manage and mitigate risk, and
balance it off against reward. Unfortunately, there seems to be too
much of an emotional investment in this concept.

If they vibration can't be fixed, so what?

So, they've wasted a lot of money that could have gone toward a more
viable concept from the beginning.

They'll still want the
five-segment SRB for the Ares V, so that will stay in development.

It depends on who "they" is. There was no Shuttle-derived Ares V
before Mike Griffin's arrival at NASA, and there's no particular
reason to think that it will survive his departure, particularly since
it exists only in the dreams of a few engineers.

They could probably build Ares 1 with a liquid first stage powered by
RS-68 engines, so they can mainatane the technical continuity between
1 and V. But that assumes it can't be fixed, and because (A) I am not
a time traveler from 2015 who knows what happened; (B) haven't already
tried to build Ares 1 on my own and found out what happened; or (C)
don't have a supercomputer better than NASA's that makes infallible
simulations, I do not know what will happen with that. Maybe they'll
fix it; maybe they won't. But that is a long way from predicting they
won't as if that's an accomplished fact.

I'm not predicting that they won't. I'm saying that it's highly
likely, though, based on my understanding of the issues, both
technical and political.