As a general rule, whenever someone uses the phrase "human rated," or
"human rating," they can be safely ignored as ignorami who don't know
what the phrase means. I wrote a book about this.
On 2019-07-10 10:24, 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.
Christopher Burnside (christopher.g.burnside@xxxxxxxxx) wrote:
<< Now, let me say something actually about orion. I'm not an expert
in the field of aerodynamics. I have read reports and I read the
papers you link above. I agree with you, the capsule is unstable.
That is not necessarily bad design though. They may have other
reasons for it (and probably do). I don't know why that was chosen.
I have hazy memory, but I think the Apollo CM was also unstable in
some flow regimes (especially following aborts). So take a look at
the entire system as a whole. You may find that the design is quite
solid given all of the trades that were made for it. >>
As Christopher notes, there were several possible tumble modes on
Apollo. After a high altitude abort, the dynamic pressure at apogee
would be too low for the canards on the Launch Escape System to
reorientate the Crew Module. Throw in thrust misalignment on the
abort motor and the capsule could end up in a tumble through apogee.
RCS could be used to stop the tumble, or you could deploy the drogues
once the dynamic pressure built up.
Capsules typically have two main stable points, nose forward and blunt
base forward, with typically low damping in-between.
A key point of the AA-2 test was, after apogee, to reorientate the
launch abort system and the crew module to blunt base forward, and
then damp out the rates so the crew module would get a clean
separation for a descent of the capsule until the point where the
drogue parachutes would have been deployed. Once you buy into having
an active system with an attitude control motor, rather than the
passive system on Apollo that used nose weight ballast on the LES to
ensure adequate stability, the attitude control motor can be used to
damp the rates after reorientation so the capsule can coast until the
point where the drogues would have deployed. And this worked during
the AA-2 test.
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?
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.
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.
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.
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.
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.
Again, reluctant to respond. But I think moderating the list is not a
good idea.
Charles E. (Chuck) Rogers
-----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
