In article ,
says...

On 2019-06-08 16:18, Fred J. McCall wrote:

Most capsules aren't pure ballistic objects. They can generate lift.

At 340km altitude, do they generate any lift? Aren't they pure ballistoc
at that point?

Capsules have an offset CG and that combined with their conical (or
biconic) shape produces lift as they pass through the atmosphere.
Obviously there is no atmosphere to speak of at 340 km altitude, but
what's your point? You brought up reentry and landing so the capsule
would necessary have to pass through the atmosphere to do that.

99.6% clear. The 400 ms at most that you can't fly through aren't
going to appreciably affect anything.

So what you are stating is that NASA is perfectly OK with de-orbiting
any any time because the odds of being at the wrong place and wrong time
during that 400ms are so low as to not even bother?

That's not what he said. The 400ms in time difference would be between
the "ideal" reentry burn time and one which had to be chosen to "miss" a
Starlink. These things are traveling bloody fast in orbit, so that's
why the time difference is only 400ms.

If they do "aim" to take the threat seriously and pass between 2
satellites based on their orbital elements, is there confidence that a
de-orbit burn can not only start right on time (easy) but also
decelerate at the exact rate (consider a capsule's mass may not be fixed
depending on what cargo they are returning) such that they will cross
path with Starlink orbit at just the right time?

This reads like word salad to me at 9:40 a.m. local time.

We keep telling you this isn't the big problem you make it out to be!
Space is effing big. The max delay for a reentry burn is only 400 ms.
Any difference in trajectory caused by that could be made up by a
capsule or lifting body via hypersonic lift during reentry through the
atmosphere.

Again, look at the landing accuracy of Apollo capsules. This was
achieved partly due to their ability to generate a significant amount of
hypersonic lift.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.