The six windows located at the forward flight deck commander and
pilot stations provide forward, left and right viewing. The two
overhead windows and two payload-viewing windows at the aft station
location on the flight deck provide rendezvous, docking and payload
viewing. There is also a window in the middeck side hatch.
The six platform-shaped forward windows are the thickest pieces
of glass ever produced in the optical quality for see-through viewing.
Each consists of three individual panes. The innermost pane is constructed
of tempered aluminosilicate glass to withstand the crew compartment
pressure. It is 0.625 of an inch thick. Aluminosilicate glass is
a low-expansion glass that can be tempered to provide maximum mechanical
strength. The exterior of this pane, called a pressure pane, is
coated with a red reflector coating to reflect the infrared (heat
portion) rays while transmitting the visible spectrum.
The center pane is constructed of low-expansion, fused silica glass
because of its high optical quality and excellent thermal shock
resistance. This pane is 1.3 inches thick.
The inner and outer panes are coated with a high-efficiency, anti-reflection
coating to improve visible light transmission. These windows withstand
a proof pressure of 8,600 psi at 240º F and 0.017 relative
The outer pane is made of the same material as the center pane
and is 0.625 of an inch thick. The exterior is uncoated, but the
interior is coated with high-efficiency, anti-reflection coating.
The outer surface withstands approximately 800º F.
Each of the forward six windows' outer panes measures 42 inches
diagonally, and the center and inner panes each measure 35 inches
diagonally. The outer panes of the forward six windows are mounted
and attached to the forward fuselage. The center and inner panes
are mounted and attached to the crew compartment. Redundant seals
are employed on each window. No sealing/bonding compounds are used.
The two overhead windows at the flight deck aft station are identical
in construction to the six forward windows except for thickness.
The inner and center panes are 0.45 of an inch thick, and the outer
pane is 0.68 of an inch thick. The outer pane is attached to the
forward fuselage, and the center and inner panes are attached to
the crew compartment. The two overhead windows' clear view area
is 20 by 20 inches. The left-hand overhead window provides the crew
members with a secondary emergency egress. The inner and center
panes open into the crew cabin, and the outer pane is jettisoned
up and over the top of the orbiter. This provides a secondary emergency
exit area of 20 by 20 inches.
On the aft flight deck, each of the two windows for viewing the
payload bay consists of only two panes of glass, which are identical
to the forward windows' inner and center panes. The outer thermal
panes are not installed. Each pane is 0.3 of an inch thick. The
windows are 14.5 by 11 inches. Both panes are attached to the crew
The side hatch viewing window consists of three panes of glass
identical to the six forward windows. The inner pane is 11.4 inches
in diameter and 0.25 of an inch thick. The center pane is 11.4 inches
in diameter and 0.5 of an inch thick. The outer pane is 15 inches
in diameter and 0.3 of an inch thick.
During orbital operations, the large window areas of transparency
expose the flight crew to sun glare; therefore, window shades and
filters are provided to preclude or minimize exposure. Shades are
provided for all windows, and filters are supplied for the aft and
overhead viewing windows. The window shades and filters are stored
in the middeck of the orbiter crew compartment. Attachment mechanisms
and devices are provided for their installation at each window on
the flight deck.
The forward station window shades (W-1 through W-6) are fabricated
from Kevlar/epoxy glass fabric with silver and Inconel-coated Teflon
tape on the outside surface and paint on the inside surface. When
the shade is installed next to the inner window pane, a silicone
rubber seal around the periphery deforms to prevent light leakage.
The shade is held in place by the shade installation guide, the
hinge plate and the Velcro keeper.
The overhead window shades (W-7 and W-8) are nearly the same as
the forward shades; but the rubber seal is deleted, and the shade
is sealed and held in place by a separate seal around the window
opening, a hinge plate and secondary frame, and Velcro retainer.
The overhead window filters are fabricated from Lexan and are used
interchangeably with the shades.
The aft window shades (W-9 and W-10) are the same as the overhead
window shades except that a 0.63-inch-wide strip of Nomex Velcro
has been added around the perimeter of the shade. The shade is attached
to the window by pressing the Velcro strip to the pile strip around
the window opening. The aft window filters are the same as the overhead
window filters except for the addition of the Velcro hook strip.
The filters and shades are used interchangeably.
The side hatch window cover is permanently attached to the window
frame and is hinged to allow opening and closing.
The contractor for the windows is Corning Glass Co., Corning, N.Y.