JF Mezei wrote on Sat, 8 Jun 2019
00:48:55 -0400:

On 2019-06-07 06:24, Jeff Findley wrote:

Not any more than flying thousands of aircraft creates a "conflict" in
the air.

In flight, aircraft are assigned non conflicting flight paths, just like
satellites. The difference is that a plane that is following another
one on same path can be told to slow down to maintain its distance.


Spacecraft, too. All the orbital elements are known. Missing them by
a wide margin isn't difficult.


And the bigger difference is that a plane can be told to circle airport
until the plath to ;land is clear, planes on the ground can be held to
create openings for planes to land.

Musk can't just tell its satellites to hold on so some spaceship can
re-enter.


Actually he can. All his satellites have thrusters to allow them to
'dodge' orbital debris and thus they could presumably adjust orbits if
necessary to allow something reentering to get past them.


If a re-entering spaceship slows down or accelerates to avoid one
satellite during de-orbit, it now has to deal with other satellites that
may be in conflict.


Take off your shoes and figure it out. There are only around 50
satellites per orbital plane. Go break out your crayons and figure
out how far apart that puts the satellites.


If you're landing anywhere in the Pacific, it is easier to dodge
satellites below. But if you are tarketing an X on a landing pad, unless
you are given lots of cross range like the Shuttle, you have 2 orbit
opportunities per day. What happens when both have conflicts?


Your premise is bull****. You can come down almost any time and miss
all the satellites.


These contellations are meant to provide coverage 24/7 in every area of
covered continents. And because they are verlo low orbit, each satellite
has small footprint, which means neighouring satelites need to be
nearby. So is re-enty really that easy and without concern?


Do the ****ing math. Given 50 satellites per orbital plan at around
400 km altitude (the lowest ones; higher ones will be further apart).
That's around 7.2 degrees between satellites. The Earth has a radius
of 12,742 kilometers. Add in the altitude of the orbits and you get
around 13,100 kilometers for the radius of the circle and a
circumference of around 82,300 kilometers for a spacing between
satellites in the same orbital plan of around 1650 kilometers. If you
can't hit a 1600 kilometer 'slot' to reenter, you probably have no
business putting things in orbit.

So yes, reentry is really that easy and without concern. You've been
told three times now (once by Jeff and twice by me).


Commercial aircraft have limits on how close they can be to each other
when at same altitude.


Yes, they do. So what?


How close to a Starlink/Oneweb/other satellite would NASA allow a
re-entering spaceship pass as it descends through their altitudes?


Mostly that isn't NASA's say, since they don't own most of the
vehicles.


Are we talking a minimum of 1m% 100m? 1km? 100km?


Even taking your preposterously large upper number of 100 km for a
'near miss' (the actual 'warning threshold' is about an order of
magnitude smaller than that) there is more than 16 times as much space
between even satellites in the lowest StarLink orbit.

Again, THIS IS A NON ISSUE, SO ****ING DROP IT ALREADY. I once again
did the basic math for you. You know, you could just do it for
yourself and eliminate a lot of stupid questions on your part. Or you
could believe it when someone gives you an answer and stop trying to
push for your stupid questions.


--
"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