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| Jeff Findley... |
 Posted: Fri Oct 23, 2009 10:20 am |
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"Fred J. McCall" <fjmccall at (no spam) gmail.com> wrote in message
news:nj02e55g7bdc1pj2799unigvb96nkdd5jg at (no spam) 4ax.com...
[quote]Brian Thorn <bthorn64 at (no spam) suddenlink.net> wrote:
:One could also argue that the extreme height/width ratio of Ares I
:needs to be proven a bit before trusting it with an upper stage and
:Orion CSM. Lord knows, we've been hearing "it will be impossible to
:control!" and "the wind will blow it into the tower" often enough for
:the last four years.
But until you've got real engines and real structure test flights
won't tell you anything about controllability or potential resonant
frequencies.
[/quote]
True. I write engineering softare for a living and could tell you about
dozens of cases where customers have changed seemingly small things in a
design only to find out that the overall design doesn't work anymore. Of
course, we sign NDA's for everything we do, so I can't openly talk about any
specifics.
In laymen's terms, just because Ares I-X may fly successfully doesn't mean
that Ares I won't be problem free. The two designs just aren't similar
enough to extrapolate much from Ares I-X and be confident that it will work
for Ares I.
Jeff
--
"Take heart amid the deepening gloom
that your dog is finally getting enough cheese" - Deteriorata - National
Lampoon |
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| Fred J. McCall... |
| Posted: Fri Oct 23, 2009 11:07 am |
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"Jeff Findley" <jeff.findley at (no spam) ugs.nojunk.com> wrote:
:
:"Fred J. McCall" <fjmccall at (no spam) gmail.com> wrote in message
:news:nj02e55g7bdc1pj2799unigvb96nkdd5jg at (no spam) 4ax.com...
:> Brian Thorn <bthorn64 at (no spam) suddenlink.net> wrote:
:> :One could also argue that the extreme height/width ratio of Ares I
:> :needs to be proven a bit before trusting it with an upper stage and
:> :Orion CSM. Lord knows, we've been hearing "it will be impossible to
:> :control!" and "the wind will blow it into the tower" often enough for
:> :the last four years.
:>
:> But until you've got real engines and real structure test flights
:> won't tell you anything about controllability or potential resonant
:> frequencies.
:
:True. I write engineering softare for a living ...
:
Me too, among other things.
:
:... and could tell you about
:dozens of cases where customers have changed seemingly small things in a
:design only to find out that the overall design doesn't work anymore. Of
:course, we sign NDA's for everything we do, so I can't openly talk about any
:specifics.
:
I used to work Simulation for missiles. There's a lot of stuff about
interactions between the vehicle and the real world you need to know
in order to produce a high fidelity simulation. You can simulate 'the
world' to a very high order and your simulation may still be junk if
you don't know all the details about how it impacts the vehicle.
:
:In laymen's terms, just because Ares I-X may fly successfully doesn't mean
:that Ares I won't be problem free. The two designs just aren't similar
:enough to extrapolate much from Ares I-X and be confident that it will work
:for Ares I.
:
They do better to build a scale model and run time in a hypersonic
wind tunnel. At least that way they'd get a decent first
approximation of the flow fields around the vehicle. I honestly don't
see what this 'test shot' will tell them that they can actually use.
--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw |
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| me... |
| Posted: Fri Oct 23, 2009 1:15 pm |
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On Fri, 23 Oct 2009 10:07:36 -0700, Fred J. McCall
<fjmccall at (no spam) gmail.com> wrote:
[quote]They do better to build a scale model and run time in a hypersonic
wind tunnel. At least that way they'd get a decent first
approximation of the flow fields around the vehicle. I honestly don't
see what this 'test shot' will tell them that they can actually use.
[/quote]
If one were to actually look, there has been a fairly extensive
aerodynamic database development program, which includes both wind
tunnel tests and CFD simulations over the flight trajectory.
Correlating/correcting sunstantially subscale wind tunnel data to full
scale flight data in itself is not necessarily a trivial exercise, nor
an exact science.
Does anyone remember the last new launch vehicle which NASA was even
remotely associated with? Exactly how did the ATK ALV-X1 preform, and
what were the findings of the ATK accident investigation? |
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| Pat Flannery... |
| Posted: Fri Oct 23, 2009 2:30 pm |
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Jeff Findley wrote:
[quote]The RCS could be the design they're planning on using for Ares I, but I seriously
doubt it. For this flight they only need roll control for first stage burn
since the SRB TVC will handle the rest. I'm not sure if Ares I will need
more than roll control on its RCS (for example, to keep the upper stage
pointed in the right direction between first stage separation and successful
start of the upper stage engine).
[/quote]
Back when Ares 1 first got rolling, Scott Lowther was still working for
ATK and noticed that their first paintings of the vehicle showed no
means of roll control, so he pointed that out to them.
Apparently they hadn't thought of that problem in regards to using the
SRB, so added the roll control engines to the design on later paintings.
That gives you some insight into the amount of thought that went into
its design.
Ares 1 is what happens when you let space cadets rather than engineers
design a launch vehicle...it's always going to be so simple to do, and
it ends up being a compete mess.
SSTO?
Hell, piece of cake.
Pat |
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| kT... |
| Posted: Fri Oct 23, 2009 2:36 pm |
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Pat Flannery wrote:
[quote]Ares 1 is what happens when you let space cadets rather than engineers
design a launch vehicle...it's always going to be so simple to do, and
it ends up being a compete mess.
SSTO?
[/quote]
http://en.wikipedia.org/wiki/Single-stage-to-orbit
"The early Atlas rocket is an expendable SSTO by some definitions. It is
a "stage-and-a-half" rocket, jettisoning two of its three engines during
ascent but retaining its fuel tanks and other structural elements.
However, by modern standards the engines ran at low pressure and thus
not particularly high specific impulse and were not especially
lightweight; using engines operating with a higher specific impulse
would have eliminated the need to drop engines in the first place."
"The first stage of the Titan II had the mass ratio required for
single-stage-to-orbit capability with a small payload. A rocket stage is
not a complete launch vehicle, but this demonstrates that an expendable
SSTO was probably achievable with 1962 technology."
[quote]Hell, piece of cake.
[/quote]
"Single-stage rockets were once thought to be beyond reach, but advances
in materials technology and construction techniques have shown them to
be possible. For example, calculations show that the Titan II first
stage, launched on its own, would have a 25-to-1 ratio of fuel to
vehicle hardware. It has a sufficiently efficient engine to achieve
orbit, but without carrying much payload."
"Ditto Saturn S-IVB and for all practical purposes, the SSME."
Unless it is federally mandated, it ain't gonna happen.
Americans are too fucking stupid nowadays.
Now you tell me, why is that?
> Pat |
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| Pat Flannery... |
| Posted: Fri Oct 23, 2009 2:38 pm |
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Brian Thorn wrote:
[quote]Then so was the first Saturn I launch. The engines and tankage were
all flight-proven, everything above Stage 1 was dummy, and the payload
mockup didn't share Apollo's outer moldline.
No one calls SA-1 a stunt.
[/quote]
Of course, at that point Saturn I was seen as having uses other than
just Apollo-related ones, including military ones like boosting Dynasoar
into orbit.
The strange problem Saturn I ran into is that the the rocket advanced so
rapidly from design to first flight that they hadn't had time to develop
any payloads for it by the time it was ready to go.
Oh, for those days again. ;-)
Pat |
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| Fred J. McCall... |
| Posted: Fri Oct 23, 2009 7:48 pm |
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me <me at (no spam) mine.net> wrote:
:On Fri, 23 Oct 2009 10:07:36 -0700, Fred J. McCall
:<fjmccall at (no spam) gmail.com> wrote:
:
:
:>They do better to build a scale model and run time in a hypersonic
:>wind tunnel. At least that way they'd get a decent first
:>approximation of the flow fields around the vehicle. I honestly don't
:>see what this 'test shot' will tell them that they can actually use.
:
:If one were to actually look, there has been a fairly extensive
:aerodynamic database development program, which includes both wind
:tunnel tests and CFD simulations over the flight trajectory.
:Correlating/correcting sunstantially subscale wind tunnel data to full
:scale flight data in itself is not necessarily a trivial exercise, nor
:an exact science.
:
But it does require that you actually fly the real vehicle to do it.
Which is NOT what they're doing here...
--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw |
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| Pat Flannery... |
| Posted: Sat Oct 24, 2009 2:10 am |
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Joseph Nebus wrote:
[quote]Though come to think of it, how long did the Little Joe and Big
Joe rockets spend at the launchpad waiting to be gotten ready for their
tests?
[/quote]
Do you mean Redstone and Big Joe?
Little Joe was a multi-solid-fueled rocket test vehicle for the Mercury
abort and recovery systems: http://www.astronautix.com/lvs/litlejoe.htm
Pat |
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| me... |
| Posted: Sat Oct 24, 2009 8:57 am |
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On Fri, 23 Oct 2009 18:48:36 -0700, Fred J. McCall
<fjmccall at (no spam) gmail.com> wrote:
[quote]But it does require that you actually fly the real vehicle to do it.
Which is NOT what they're doing here...
[/quote]
What makes you think they haven't developed models all the way through
a trajectory for 1-X itself? |
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| Fred J. McCall... |
| Posted: Sat Oct 24, 2009 4:00 pm |
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Guest
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me <me at (no spam) mine.net> wrote:
:On Fri, 23 Oct 2009 18:48:36 -0700, Fred J. McCall
:<fjmccall at (no spam) gmail.com> wrote:
:
:
:>But it does require that you actually fly the real vehicle to do it.
:>
:>Which is NOT what they're doing here...
:
:What makes you think they haven't developed models all the way through
:a trajectory for 1-X itself?
If 1-X is your goal vehicle, that's all well and good. If it's not,
you're spending a lot of money for nothing useful.
--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine |
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| hallerb at (no spam) aol.com... |
| Posted: Sun Oct 25, 2009 9:00 am |
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[quote]If 1-X is your goal vehicle, that's all well and good. �If it's not,
you're spending a lot of money for nothing useful.
[/quote]
nasa is excellent and wasting money........... |
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| Brian Thorn... |
| Posted: Sun Oct 25, 2009 6:05 pm |
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On Fri, 23 Oct 2009 01:37:48 -0500, OM <om at (no spam) sci.space.history> wrote:
[quote]but
even though I want to see "The Stick Jr" a success, it won't surprise
me one iota if it EPIC FAILS.
[/quote]
Just as an aside, I would like to nominate "Epic Fail" to the 2009
Banned Phrases List. When it shows up as the name of a TV show's
episode, it's overused.
[quote]Then again, did anyone notice that the paint job's really reminiscent
of a certain Jupiter-C?
[/quote]
NASA calls it a "Z Stripe" in the press kit.
Brian |
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| Pat Flannery... |
| Posted: Sun Oct 25, 2009 11:17 pm |
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Brian Thorn wrote:
[quote]NASA calls it a "Z Stripe" in the press kit.
[/quote]
Here's a goody; I can see why they want clear weather to observe the
whole ascent and descent, but now the thing has a static electricity
constraint that can cancel its launch even if there aren't active storms
around:
http://spaceflightnow.com/ares1x/091025weather/
Weather constraints were one of the things that made the STS such a
reliably on-time launch system.
Pat |
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| Rick Jones... |
| Posted: Mon Oct 26, 2009 7:56 am |
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[quote]If 1-X is your goal vehicle, that's all well and good. ???If it's not,
you're spending a lot of money for nothing useful.
nasa is excellent and wasting money...........
[/quote]
You aren't viewing it spun-around to the correct angle - it isn't
waste, it is high-tech stimulus :)
Is it me, or does The Schtick look like a giant dart sans the fins?
Will there be a mile-diameter dartboard target on the ocean where it
lands?-)
rick jones
--
web2.0 n, the dot.com reunion tour...
these opinions are mine, all mine; HP might not want them anyway... 
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
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| Greg D. Moore (Strider)... |
| Posted: Mon Oct 26, 2009 2:24 pm |
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"Rick Jones" <rick.jones at (no spam) hp.com> wrote in message
news:hc4nrn$ikb$2 at (no spam) usenet01.boi.hp.com...
[quote]If 1-X is your goal vehicle, that's all well and good. ???If it's not,
you're spending a lot of money for nothing useful.
nasa is excellent and wasting money...........
You aren't viewing it spun-around to the correct angle - it isn't
waste, it is high-tech stimulus :)
Is it me, or does The Schtick look like a giant dart sans the fins?
Will there be a mile-diameter dartboard target on the ocean where it
lands?-)
[/quote]
Alert Taco Bell, they have experience with this sort of thing.
--
Greg Moore
Ask me about lily, an RPI based CMC. |
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