JF Mezei wrote:

On 2017-05-21 14:43, Fred J. McCall wrote:

capsule does, with some minimal lift, gives you 3g or more with jolts
much higher. Note that the Shuttle still restrained occupants in
seats, not just a mattress and some bungee cords.


I never heard about such jolts or hard variations in air density that
would create such jolts.


So you're ignorant. We knew that. How big do you think a density
change needs to be at Mach 25 to ruin your day?


Also, if you are at 3G and then go to 4G for a second and back to 3G,
everything remains "glued" to the floor. Nothing flies all over the place.


You assume all accelerations are in the same direction and normal to
the 'floor'. You assume wrong. Capsules 'wobble' on reentry.


You,d have to suddently go from 3G to 0G and stay there long enough for
gear to start floating, and at 0G, a mere bungee cord would be more than
enough to keep gear on the floor.

At de-orbit burn, floating stuff would fall to the floor, then go back
to floating in 0G until atmosphere starts to generate G forces, at which
point they would fall slowly to floor as G forces increase slowly.

So I really do not unerstand your argument that a nominal re-entry is
violent.


Your lack of understanding doesn't change the facts. You have your
answer. You think you know better. Go sod yourself.


Granted, if the capsule starts tumbling, things will be violent, but
isn't the shape designed to prevent this?


Actually, US capsules are typically biconic, which means they have two
semi-stable attitudes. One is with the heat shield 'down'. The other
is with the nose 'down'. Capsules are NOT perfectly stable on
reentry, which means they 'wobble' on the way down and that will throw
**** inside the capsule around if it isn't properly restrained. If
they ever 'wobble' far enough so that they flip to the other stable
configuration, you're all dead because that end has no heat shield on
it.

In fact, biconic capsules have a certain amount of lift. This means
two things:

1) They actually 'fly' a little bit on the way down, which reduces the
deceleration forces so you only get 3-5 g instead of 9+.

2) Because they actually 'fly' a little bit, down isn't constant.

Now, because there is lift, the decelleration vector isn't straight
through the floor and varies based on angle of attack. Again, a
biconic body is not perfectly stable, so it will also tend to 'wobble'
a bit. But you know better, so why do you bother to ask questions in
the first place?


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson