The black ceramic tiles located on the bottom and along the wing tips and nose of the orbiter protect it from the nearly 1,648 degrees Celsius (3000 degrees F) temperatures. To rid the orbiter of some of this heat, it makes a series of small rolls from left and right throughout its fiery fall.
The "roll reversals" (banking left and right) are done to reduce speed and altitude, not to rid the orbiter of heat.
As for the windows being exposed to heat, they are basically protected by the high angle of attack that the shuttle has when it re-enters Earth's atmosphere. The nose is pitched up at 40 degrees, so that the frictional heat is absorbed mostly by the tiles on the underside, and the wing leading edges.
[edit on 26-11-2008 by Mogget]
[edit on 26-11-2008 by Mogget]
[edit on 26-11-2008 by Mogget]
