The wing is an aerodynamic
lifting surface that provides conventional lift and control for
the orbiter. The left and right wings consist of the wing glove;
the intermediate section, which includes the main landing gear well;
the torque box; the forward spar for mounting the reusable reinforced
carbon-carbon leading edge structure thermal protection system;
the wing/elevon interface; the elevon seal panels; and the elevons.
The wing is constructed of conventional aluminum alloy with a multirib
and spar arrangement with skin-stringer-stiffened covers or honeycomb
skin covers. Each wing is approximately 60 feet long at the fuselage
intersection and has a maximum thickness of 5 feet.
The forward wing box is an extension of the basic wing that aerodynamically
blends the wing leading edge into the midfuselage wing glove. The
forward wing box is a conventional design of aluminum ribs, aluminum
tubes and tubular struts. The upper and lower wing skin panels are
stiffened aluminum. The leading edge spar is constructed of corrugated
The intermediate wing section consists of the conventional aluminum
multiribs and aluminum tubes. The upper and lower skin covers are
constructed of aluminum honeycomb. A portion of the lower wing surface
skin panel includes the main landing gear door. The intermediate
section houses the main landing gear compartment and reacts a portion
of the main landing gear loads. A structural rib supports the outboard
main landing gear door hinges and the main landing gear trunnion
and drag link. The support for the inboard main landing gear trunnion
and drag link attachment is provided by the midfuselage. The main
landing gear door is conventional aluminum honeycomb.
The four major spars are constructed of corrugated aluminum to
minimize thermal loads. The forward spar provides the attachment
for the thermal protection system reusable reinforced carbon-carbon
leading edge structure. The rear spar provides the attachment interfaces
for the elevons, hinged upper seal panels, and associated hydraulic
and electrical system components. The upper and lower wing skin
panels are stiffened aluminum.
The elevons provide orbiter flight control during atmospheric flight.
The two-piece elevons are conventional aluminum multirib and beam
construction with aluminum honeycomb skins for compatibility with
the acoustic environment and thermal interaction. The elevons are
divided into two segments for each wing, and each segment is supported
by three hinges. The elevons are attached to the flight control
system hydraulic actuators at points along their forward extremities,
and all hinge moments are reacted at these points. Each elevon travels
40 degrees up and 25 degrees down.
The transition area on the upper surface between the torque box
and the movable elevon consists of a series of hinged panels that
provide a closeout of the wing-to-elevon cavity. These panels are
of Inconel honeycomb sandwich construction outboard of wing station
Y w 312.5 and of titanium honeycomb sandwich construction inboard
of wing station Y w 312.5. The upper leading edge of each elevon
incorporates titanium rub strips. The rub strips are of titanium
honeycomb construction and are not covered with the thermal protection
system reusable surface insulation. They provide the sealing surface
area for the elevon seal panels.
The exposed areas of the wings, main landing gear doors and elevons
are covered with reusable surface insulation thermal protection
system materials except for the elevon seal panels.
Thermal seals are provided on the elevon lower cove area along
with thermal spring seals on the upper rub panels. Pressure seals
and thermal barriers are provided on the main landing gear doors.
The wing is attached to the fuselage with a tension bolt splice
along the upper surface. A shear splice along the lower surface
in the area of the fuselage carry-through completes attachment interface.
Prior to the manufacturing of the wings for Discovery (OV-103)
and Atlantis (OV-104), a weight reduction program resulted in a
redesign of certain areas of the wing structure. An assessment of
wing air loads was made from actual flight data that indicated greater
loads on the wing structure. As a result, to maintain positive margins
of safety during ascent, structural modifications were incorporated
into certain areas of the wings. The modifications consisted of
the addition of doublers and stiffeners.
The wing, elevon and main landing gear door contractor is Grumman
Corp., Bethpage, N.Y.