Allen Thomson wrote:

OK, now that your real question has been answered, I have another:

How do the ISSonauts keep the inside surfaces of big windows optically
clean?

Absolute ethyl alcohol (which we used to use for optical surfaces at
LPL and helped with Solstice Celebrations) and cotton cloths? Probably
not, given alcohol's unfortunate propensity to combine energetically
with oxygen.

Windex and paper towels?

Saliva and shirtsleeves?

Or what?

Compressed air? I get the feeling that the astronauts are going to be
discouraged from touching the window panes.

Pat