The orbiter lighting system provides both interior and exterior
lighting. The interior lighting provides illumination for display
and control visibility and general flight station and crew equipment
operations. Exterior lighting provides illumination for payload
bay door operations, extravehicular activity, remote manipulator
system operations, and stationkeeping and docking. Interior lighting
consists of floodlights, panel lights, instrument lights, numeric
lights and annunciator lights. Annunciator lighting is discussed
with the caution and warning system. Exterior lighting consists
of floodlights and spotlights.
Interior floodlights provide general illumination throughout
the crew cabin and allow the flight crew to function within the
flight deck, middeck, airlock and tunnel adapter (if installed).
Both fluorescent and incandescent lamps are used. Emergency lighting
is provided by selected fixtures that are powered via a separate
power input from an essential bus.
Dual fluorescent lamp fixtures provide lighting for the mission
station and payload station. The mission station lighting is controlled
by an on/off switch with a rotary control switch to control brightness
on panel R10. The payload station lighting is controlled by an
on/off switch with a rotary control switch to control brightness
on panel L9.
A single fluorescent lamp fixture is employed on each side of
the commander's and pilot's forward flight deck glareshield, the
commander's and pilot's side consoles and the orbit station. The
commander's glareshield light is controlled by the bright, var
, off switch and a dim, brt rotary control on panel O6. The dim,
brt rotary control operates in conjunction with the var position.
The pilot's glareshield light functions the same as the commander's,
except the control is on panel O8.
The commander's side console light is controlled by an integral
off/variable/on control switch. The pilot's side console light
is also controlled by an integral off/variable/on control switch.
The orbit station light is controlled by an on/off switch and
dim, brt rotary control on panel A6.
The seat/center console floodlight has two incandescent bulbs:
one illuminates the commander's lap or the center console, and
the other illuminates the pilot's lap or the center console. The
commander or pilot can select either the lap or center console,
not both. The commander's seat or console light is controlled
by the left seat/ctr cnsl flood , seat/off/ctr cnsl switch and
the dim, brt rotary control on panel O6. The pilot's seat or console
light is controlled by the right seat ctr cnsl flood, seat/off/ctr
cnsl switch and the dim, brt rotary control on panel O8.
The middeck ceiling floodlight fixtures are located behind a
translucent polycarbonate material. They are the same fixtures
as those at the orbit station and are individually controlled
by on/off switches on panel M013Q. The middeck panel M013Q is
lighted by a small fluorescent lamp at each end of the recessed
panel and is controlled by the M013Q on/off switch on the panel.
The waste management compartment floodlight is also the same
as the orbit station fixture and is controlled by an on/off switch
on panel ML18F.
The galley and middeck sleep station bunks (if installed) use
the same floodlights as the commander's and pilot's flight deck
consoles and are also controlled individually.
The airlock floodlights are similar to those at the commander's
and pilot's flight deck side consoles, except they are controlled
by switches on panels AW18A and M013Q.
If the tunnel adapter is installed for a Spacelab mission, the
floodlights are also similar to those at the commander's and pilot's
side consoles. Tunnel adapter lights 2, 3 and 4 are controlled
by individual on/off switches on the tunnel adapter panel. The
remaining tunnel adapter light is controlled by the tunnel adapter
1 on/off switch on panel M013Q and the on/off 1 switch on the
tunnel adapter panel. The emergency floodlights are controlled
by on/off switches on either panel C3 or ML18F.
Many flight deck instrument panels have integral lighting that
illuminates the panel nomenclature and markings on the displays
and controls. This illumination aids the flight crew in locating
displays and controls while operating the orbiter. Panel lighting
is transmitted from behind a panel overlay through the panel nomenclature,
making it appear white-lighted. It is also transmitted to the
edges of the displays and controls for general illumination. The
lighting source consists of small incandescent, grain-of-wheat
lamps mounted between the metal panel face and the plastic panel
overlay. The overlay has a layer of white paint and a layer of
gray paint on the top surface. The panel nomenclature is formed
by etching the letters and symbols into the gray paint, leaving
the white layer underneath. The panel, mission station and orbit
station lighting is controlled by off, var, brt rotary controls
on panels O6, O8, R10 and A6.
The flight deck instruments have integral lighting that enables
the flight crew to read the displayed data. Lighting is provided
by incandescent lamps located behind the face of the instruments.
Prisms are used to distribute the light evenly over the face.
Instrument, lighting panel, and orbit station lighting are controlled
by off, var, brt rotary controls on panels O6, O8 and A6.
Six indicators on the flight deck use illuminated numeric (digital)
readouts to display data. The illumination is provided by a single
incandescent lamp in each segment of a digit. Seven segments are
required to generate the numbers zero through nine. Each numeric
indicator has a red light to indicate failures in the indicator
and will be illuminated when any lamp in the indicator fails.
The six numeric (digital) indicators are event time (panels F7
and A4), mission time (panels O3 and A4), RCS/OMS prplt qty (panel
O3) and rri (rendezvous radar) (panel A2). The panel lighting
and numeric orbit station lighting are controlled by off, var,
brt rotary controls on panels O8 and A6.
The exterior floodlights improve visibility for the flight crew
during payload bay door operations, EVA operations, RMS operations,
and stationkeeping and docking. The payload bay floodlights are
controlled by switches on panel A7. The RMS floodlight is also
controlled on panel A7.
The payload bay floodlights are metal halide lamps that are gas
discharge arc tubes similar to mercury vapor lamps. Two different
fixtures are used with the lamps: one fixture mounts the floodlight
on the payload bay forward bulkhead and the other fixture mounts
the floodlight within the payload bay. The RMS floodlight uses
an incandescent lamp. It is located near the RMS end effector.