To All: I’mreluctant to respond to some of Craig’s posts. But I’m against
moderation onthe list, and as others have noted some people may read some of
this stuff andbelieve it. It takes too much time to gothrough some of this
point by point, but I’ll hit a few highlights.
The Orion shapeis based on the Apollo shape with small changes. The center of
gravity is also similar. Thus it has many of the characteristics ofApollo
capsule. I’m sure I can find sometumbling Apollo capsule footage, I have
footage of an Apollo capsule going throughLaunch Escape System (LES) jettison
with the LES nose forward, and thenreorientating on the drogue parachutes.
Somehow I don’tthink Apollo was a deathtrap, non-“human rated”. There’s other
trades on capsule configurations, for Apollo acompeting proposal was similar to
Soyuz. But it can't be argued that the Apollo crew module wasn't successful.
ChristopherBurnside(christopher.g.burnside@xxxxxxxxx) wrote:
<< Now, let me say something actually aboutorion. I'm not an expert in the
field of aerodynamics. I have readreports and I read the papers you link
above. I agree with you, thecapsule is unstable. That is not necessarily bad
design though. They may have other reasons for it (and probably do). I don't
know whythat was chosen. I have hazy memory, but I think the Apollo CM was
alsounstable in some flow regimes (especially following aborts). So take alook
at the entire system as a whole. You may find that the design isquite solid
given all of the trades that were made for it. >>
As Christopher notes, there wereseveral possible tumble modes on Apollo. After
a high altitude abort, the dynamic pressure at apogee would be toolow for the
canards on the Launch Escape System to reorientate the CrewModule. Throw in
thrust misalignment onthe abort motor and the capsule could end up in a tumble
through apogee. RCS could be used to stop the tumble, or youcould deploy the
drogues once the dynamic pressure built up.
Capsulestypically have two main stable points, nose forward and blunt base
forward,with typically low damping in-between.
A key point ofthe AA-2 test was, after apogee, to reorientate the launch abort
system and thecrew module to blunt base forward, and then damp out the rates so
the crewmodule would get a clean separation for a descent of the capsule until
the pointwhere the drogue parachutes would have been deployed. Once you buy
into having an active systemwith an attitude control motor, rather than the
passive system on Apollo thatused nose weight ballast on the LES to ensure
adequate stability, the attitudecontrol motor can be used to damp the rates
after reorientation so the capsulecan 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 haveexpected to see a nice STABLE Capsule smash into the ground,
giving theAstronaut plenty of time to "Work the Problem", fix the Parachute
orBlow the Hatch and jump out . Instead, I was treated to a high RPM gyroride
that Disneyland wouldn't touch. The Simulated Astronauts may haveeven 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 toadd an attitude
control motor. With theattitude control motor there anyway, it can be used to
damp the rates beforethe launch abort system is jettisoned from the capsule.
And since you designed it this way, yes, if you let thecapsule coast and coast
it will eventually tumble without the drogueparachutes.
That might not have been the design trade you would havechosen, but it’s a
consistent system design.
Saying the drogue parachutes might not deploy, is likesaying the main
parachutes might not deploy. Or the parachute system may get fouled, as
happened on the first Soyuzflight. Loss of the crew is the result.
Craig Fink <webegood@xxxxxxxxx> wrote:
<< I'm the Independent Verification andValidation (IV&V) guy who just gave
NASA's Orion Capsule a Failed to meetminimum standards to be "Human Rated", due
to subsonic aerodynamicinstability. 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
beautifulaerodynamic Tail broke off under the loads of the landing rocket.
Nexttime, NASA forgets to put Parachutes onboard, have the Simulated
Astronautthrow the pyro separation breaker to prevent the beautifully
aerodynamic Tailfrom falling off and use the last solid rocket burn to soften
the landingimpact. Maybe, NASA accidentally sized the motor correctly for a
landing burn.I'm about as Independent as it gets. >>
I’ll let the last fewsentences of this paragraph speak for themselves. If
you’re joking, it’s hard to tell fromwhether you’re trying to make a serious
point.
As for the “IndependentVerification and Validation (IV&V) guy”, and “I’m about
as Independent asit 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 thishttps://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
