Apologies again for my Attitude Problem, I'm trying it again, too.
Along with getting over the shock of just how bad Apollo, Orion and CST-100
Starliner's subsonic aerodynamics truly are. I tend to focus on interesting
problems. The unstable aerodynamics of Apollo is an interesting one. It
wasn't until yesterday that I figured what is going on with the subsonic
aerodynamics, kind of feel stupid for taking so long. It's always
satisfying to figure out a problem for a better understanding of what is
going on. Also gives me some appreciation as to why Soyuz is such a great
design, even today.
Understanding the physics behind a problem like this is always the first
step to fixing it.
Still don't understand why NASA didn't take the opportunity with Orion to
fix the Apollo Capsule's Backshell Shape problem. I wounder how many other
capsule designs NASA looked before selecting this extremely bad one that
Apollo is, aerodynamically speaking. Also, gives me an appreciation of the
Soyuz Capsule and it's Robust Design.
--
Craig Fink
WeBeGood@xxxxxxxxx
On Wed, Jul 10, 2019 at 2:45 PM Redacted sender crogers168 for DMARC <
dmarc-noreply@xxxxxxxxxxxxx> wrote:
Let's try this again.
The system is designed to use drogue parachutes in certain flight regimes,
to avoid tumbling. Whatever other design mods could have been made to
allow a complete drogue-less descent through all flight regimes without
tumbling, adding drogue parachutes was (I'm sure) clearly the lightest
weight solution.
Check. Accomplished. And then the test was complete.
Part of the test was to stabilize the launch abort system and crew module
after reorientation, null the rates, and then have a clean separation with
low rates for a crew module heatshield forward coast until the drogue
parachutes would deploy.
During the descent past what would have been the drogue parachute deploy
point, the crew module tumbled. Because no drogue parachutes were
deployed. Because in certain flight regimes, like the one the crew module
was passing through, drogue parachutes need to be deployed, to prevent
tumbling. As exactly per the design.
High angular rate during tumbling? Irrelevant. It wouldn't have been
tumbling, because the drogue parachutes would have been out.
<< To say that this is the end all to all Capsule Design is ridiculous.
Everything in front of the Heat Shield is fair game for making changes to
improve Subsonic Aerodynamics. Like SpaceX and Blue Origins did. >>
And like Orion did also. While similar to Apollo, there are changes on
the backshell (leeside) profile. But within reason, changes in the leeside
shape don't have strong effects on the aerodynamics, thus they can be made
for other reasons (more internal volume as an example), and not cause any
major changes in the aerodynamics. There was an incentive to keep the
exact Apollo shape, as there were hours and hours of wind tunnel test data
and flight data. But in the end, changes in the leeside profile were made.
<< Intermetrics, Averstar, L3 or whoever is doing the IV&V on the Orion
Capsule had better do some serious soul searching before validating the
Orion Capsule and it's horrendous subsonic aerodynamics. >>
Again, with the small leeside profile changes, Orion has very Apollo-like
aerodynamics. With the aerodynamics very similar to Apollo, you're
basically saying the Apollo crew module had horrendous subsonic
aerodynamics. All capsules have some inherently bad aerodynamic
characteristics, but clearly the Apollo crew module did not have horrendous
subsonic aerodynamics.
<< To me, it is highly unusual to terminate a test while the vehicle is
still flying, to stop collecting data before it gets really bad, to stop
all the Engineering video early. The only good view of the out of control
tumble came from the Veteran guy and his new tracking camera. They are
ignoring a problem, ignore it long enough and .... >>
On AA-2 it was a fully representative launch abort system, and every
interface between between the launch abort system and the crew module was
fully representative. The crew module Outer Mold Line (OML) was correct.
The weight and CG were correct. The crew module though was a boilerplate
crew module; where it had to be accurate for the test objectives it was,
the rest was just boilerplate.
Charles E. (Chuck) Rogers
-----Original Message-----
From: Craig Fink <webegood@xxxxxxxxx>
To: arocket <arocket@xxxxxxxxxxxxx>
Sent: Wed, Jul 10, 2019 11:55 am
Subject: [AR] Re: Orion Abort Test Failure...
On Wed, Jul 10, 2019 at 12:25 PM Redacted sender crogers168 for DMARC <
dmarc-noreply@xxxxxxxxxxxxx> wrote:
To All:
I’m reluctant to respond to some of Craig’s posts. But I’m against
moderation on the list, and as others have noted some people may read some
of this stuff and believe it. It takes too much time to go through some
of this point by point, but I’ll hit a few highlights.
The Orion shape is based on the Apollo shape with small changes. The
center of gravity is also similar. Thus it has many of the
characteristics of Apollo capsule. I’m sure I can find some tumbling
Apollo capsule footage, I have footage of an Apollo capsule going through
Launch Escape System (LES) jettison with the LES nose forward, and then
reorientating on the drogue parachutes.
Somehow I don’t think Apollo was a deathtrap, non-“human rated”. There’s
other trades on capsule configurations, for Apollo a competing proposal was
similar to Soyuz. But it can't be argued that the Apollo crew module
wasn't successful.
Apologies for my initial Rant, really was just the shock of just how bad
Orion performed. I've calmed down. Sorry, I can get passionate about all
things space.
By today standard tumbling at 100 RPM should be unacceptable, 50 years ago
in a Space Race it's just fine. It was successful, but Mercury or Gemini
might perform better.
Mercury Capsule, nice for-body nose, would change it's subsonic
aerodynamics. Not sure, but would probably settle out at some attitude that
isn't above 100 RPM.
https://www.google.com/search?q=Mercury+capsule&rlz=1C1CHBD_enUS847US847&source=lnms&tbm=isch&sa=X&ved=0ahUKEwisiYiU8qrjAhUMbc0KHc_-CS0Q_AUIECgB&biw=1872&bih=1090
Gemini Capsule, again nice long nose. Probably ok subsonic aerodynamics.
Not sure how it behave subsonically either.
https://www.google.com/search?rlz=1C1CHBD_enUS847US847&biw=1872&bih=1090&tbm=isch&sa=1&ei=bCImXfD-GMmqtQa_p524DQ&q=gemini+capsule&oq=gemini&gs_l=img.3.0.0i67j0l2j0i67l2j0l3j0i67j0.187412.189007..190714...0.0..0.93.483.6......0....1..gws-wiz-img.......35i39.qArPi5kebr8
Apollo need a Docking Hatch, the decision was probably a quick one and
made sense at the time, remove the for-body nose and put a hatch there. To
say that this is the end all to all Capsule Design is ridiculous.
Everything in front of the Heat Shield is fair game for making changes to
improve Subsonic Aerodynamics. Like SpaceX and Blue Origins did.
Christopher Burnside (*christopher.g.burnside@xxxxxxxxx*) wrote:
I really don't care about what Chris has to say. He is in the SPAM folder
now and I will consider taking him out some time in the future.
Put me in your SPAM folder if you wish, I don't care.
Craig Fink <webegood@xxxxxxxxx> wrote:
<< I would have expected to see a nice STABLE Capsule smash into the
ground, giving the Astronaut plenty of time to "Work the Problem", fix the
Parachute or Blow the Hatch and jump out . Instead, I was treated to a
high RPM gyro ride that Disneyland wouldn't touch. The Simulated
Astronauts may have even died before hitting the ground. There was no
"Manual Override" even possible, no Bailing out with a Personal Parachute,
no saying goodbyes. >>
Blow the hatch and jump out? Seriously?
Yes, Seriously! A Capsule does not reach 1 gee at the ground. It achieves
1 gee at Terminal Velocity, Astronauts can get up and walk around for a
minute or so, if the Capsule is stable and falling at terminal velocity.
On the Space Shuttle we added a pole to allow the Astronauts to bail out,
if the wing doesn't fall off. Seriously, bail out if the main parachute
fails.
Again, you have a system where the design trade was made to add an
attitude control motor. With the attitude control motor there anyway, it
can be used to damp the rates before the launch abort system is jettisoned
from the capsule.
Attitude Control Jets vs Bad Subsonic Aerodynamics. Attitude Control Jets
"control authority" decrease with altitude, Aerodynamics increasing. Are
Orions attitude control jets rated to run at Sealevel? Don't answer that,
it's irrelevant.
And since you designed it this way, yes, if you let the capsule coast and
coast it will eventually tumble without the drogue parachutes.
That might not have been the design trade you would have chosen, but it’s
a consistent system design.
See comments above about design choices.
Saying the drogue parachutes might not deploy, is like saying the main
parachutes might not deploy. Or the parachute system may get fouled, as
happened on the first Soyuz flight. Loss of the crew is the result.
Some crews didn't even have pressure suits. Standards like what it means
to be "Human Rated" change with time.
Craig Fink <webegood@xxxxxxxxx> wrote:
<< I'm the Independent Verification and Validation (IV&V) guy who just
gave NASA's Orion Capsule a Failed to meet minimum standards to be "Human
Rated", due to subsonic aerodynamic instability. It's a Capsule, it's not
hard to design a stable capsule. Heck, the thing had great stability right
up to the point that beautiful aerodynamic Tail broke off under the loads
of the landing rocket. Next time, NASA forgets to put Parachutes onboard,
have the Simulated Astronaut throw the pyro separation breaker to prevent
the beautifully aerodynamic Tail from falling off and use the last solid
rocket burn to soften the landing impact. Maybe, NASA accidentally sized
the motor correctly for a landing burn. I'm about as Independent as it gets.
I’ll let the last few sentences of this paragraph speak for themselves. If
you’re joking, it’s hard to tell from whether you’re trying to make a
serious point.
Just one man's opinion, you have another fine but don't expect me to
change mine anytime soon. Don't like my opinion fine.
As for the “Independent Verification and Validation (IV&V) guy”, and “I’m
about as Independent as it gets”, IV&V is taken very seriously. But it
starts with a basic understanding of the particular system, and similar
systems, like the Apollo capsule. And it has to be from credible sources,
or it's just noise, and not of value. So I'm not really sure what formal
IV&V role you're really claiming here.
I have always taken IV&V very very seriously.
Intermetrics, Averstar, L3 or whoever is doing the IV&V on the Orion
Capsule had better do some serious soul searching before validating the
Orion Capsule and it's horrendous subsonic aerodynamics. To me, it is
highly unusual to terminate a test while the vehicle is still flying, to
stop collecting data before it gets really bad, to stop all the Engineering
video early. The only good view of the out of control tumble came from the
Veteran
guy and his new tracking camera. They are ignoring a problem, ignore it
long enough and ....
I asked my wife about what she thought of the video, she was shocked.
Doesn't take a Rocket Scientist to figure out they wouldn't want to go
along for that ride.
Drogue and Parachutes do fail. The Experiment survived the crash.
https://www.youtube.com/watch?v=6_P09vLnYMo
Pyro-bolts do malfunction .
https://en.wikipedia.org/wiki/Soyuz_TMA-11
-----Original Message-----
From: Craig Fink <webegood@xxxxxxxxx>
To: arocket <arocket@xxxxxxxxxxxxx>
Sent: Fri, Jul 5, 2019 7:56 am
Subject: [AR] Orion Abort Test Failure...
...Not Human Rated. Orion Abort Test was a complete and utter failure, yet
NASA calls it a success?
I can make some assumptions about what they did, like. The shape of the
Orion Capsule is correct. The Center of Gravity (CG) is correct. Given
these two assumptions, this Orion Capsule test was a complete and utter
failure. Back to the drawing board and re-design the entire Capsule, it's
not Human Rated.
NASA showed this
https://www.youtube.com/watch?v=4rfsDMGplZU
Yet, here is what the Orion Capsule flying through the atmosphere.
https://youtu.be/2RbbSGrO_tY?t=170
I would hardly call this "Stable" flight. Exactly how many RPM do NASA
Astronauts like to be spinning at, when they impact the water? Gees, can
you imagine what it would be like to "Work the Problem" tumbling at that
rate?
The Orion Capsule is unstable.
--
Craig Fink
WeBeGood@xxxxxxxxx
It's just my opinion.
--
Craig Fink
WeBeGood@xxxxxxxxx
