JF Mezei wrote on Tue, 2 Oct 2018
17:42:59 -0400:


The Shuttle brought "visiting" crews to ISS who came up on one shuttle
and came back down on the same shuttle.


Wrong.


Russia worked differently. Visiting crews come up on a new Soyuz, leave
it at station and return a week later on the old Soyuz.


Wrong. There is essentially no such thing as 'visiting crews' except
for the couple of tourists over the years. In those cases, the
'tourist' comes up with the new crew (who will stay for roughly six
months) and ride back down with the old crew (who have been there for
roughly six months).


When the new Soyuz docks, there is a ceremony where the seat liners from
one Soyuz and switched with those of the other. So the ISS crew now have
their seat liners in the new Soyuz, and the visiting crew have theirs on
the old Soyuz.

When Visiting crew is done visiting, they return to earth on the old soyuz.


Wrong. There is essentially no such thing as 'visiting crew' the way
you seem to be thinking of it.


And of course, those trips also provide for russian crew rotation when
the Shuttle provided crew rotation for the US segment.


Wrong. The Shuttle usually provided 'crew rotation' for everyone when
it was flying. There was no "US guys fly Shuttle and Russians fly
Soyuz" separation. Examples:

Crew 1 down (2 Russians).
Crew 2-5 up and down (total of 6 Russians).
Crew 6 up (1 Russian)

After a Shuttle hiatus where everyone flew Soyuz, Russians tended to
stay on Soyuz, as did about half of the Americans. The remaining
Americans and various foreign astronauts (Germany, France, Canada,
Japan) flew Shuttle. Belgium and Italy flew their astronauts on
Soyuz. And of course, when Shuttle was out of service, everyone flew
Soyuz.


With the current total reliance on Soyuz, there are a lot less "visiting
crews" since the Soyuz use their seats for crew rotations on both
up/down flilghts. (brings up new crewmember on new Soyuz, and the ISS
crewmembnet whose stay ends will come back down on the old Soyuz (and in
such a case, there is no need to switch the seat liners for that
crewmembe whose liner is already ion the old soyuz).


Hard to have fewer than zero, which is essentially what 'visiting
crews' numbered. Folks who rode Shuttle up and down on the same
Shuttle flight were SHUTTLE crews, not 'visiting ISS crew'. ISS has
life support for around six people. No way to support 'visiting' crew
on ISS itself.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn