Page 52 - Curriculum Visions Dynamic Book

The Space Shuttle and International Space Station
Glass has many important roles in space. The most obvious is in the windows. The Space Shuttle has 37 triple-glazed window panes. The Space Station has hundreds.
The outer panes on the front of the cockpit of the Space Shuttle are silica glass. That is because they have to stand up to the very high temperatures experienced during reentry through the atmosphere.
The inner panes are made from an alumina-rich glass: a high-strength glass that acts as the strong pane that can withstand the difference in pressure between the cabin and the vacuum in space.
The middle panes are a thick silica glass. They are safety panels, able to stand
up both to high reentry temperature and pressure. They are there in case the outer panels break.
However, the Space Shuttle has more glass than just its windows. The tiles
that cover the bottom, sides of the tail, and parts of the wingtops of the Space Shuttle, and which take the high reentry temperatures, are coated in glass powder called sinter or frit.
The most common use of glass in space is in very thin glass cover slips on solar cells. The glass contains cerium, which absorbs x-rays and prevents radiation damage to the solar cells beneath and also acts as a barrier to micrometeroid damage.
(Above) The Space Station, showing some of its windows.
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