Orbiter is the home of the crew members during the space mission. The major parts of the orbiter are:
1. The Forward Fuselage is made up of lower and upper sections that form a clam like shell around a pressurized crew compartment. It houses the support equipments of crew compartment and supports Orbiter/External Tank attachment etc.
2. The Crew Compartment is a pressurized compartment, intended to support all astronaut activities aboard the Orbiter.
The Crew Compartment has 11 windows, including six forward windows, two overhead rendezvous observation windows, two aft payload bay viewing windows and a single side hatch window. Three panes make up each window. At a total width of nearly three inches, these are the thickest windows ever designed for see-through flight applications.
The Crew Compartment contains three levels, including a flight deck located at the top, a mid deck in the center and a lower level equipment bay. The Crew Compartment is pressurized at 14.7 pounds per square-inch with an atmosphere of 80% nitrogen and 20% oxygen.
3. The Payload Bay Doors, which are opened shortly after orbit is achieved to allow heat to be released from the Orbiter. The two Payload Bay Doors are hinged at the port of the midfuselage.
Thermal seals on the Payload Bay Doors provide a relatively airtight environment within the payload bay when the doors are closed. Each Payload Bay Door is 60 feet long by 15 feet wide.
4. The Airlock is typically housed in the crew compartment mid deck. The Airlock is 83 inches long and has a diameter of 63 inches. Two pressurized sealing hatches are contained in the Airlock. Each sealing hatch has a four-inch diameter observation window.
Depending on the mission application, the Airlock can be positioned in either the crew compartment or the payload bay in support of space walk activities.
5. The Wings provide an aerodynamic lifting surface to produce conventional lift and control for the Orbiter. The left and right Wings an intermediate section that includes the main landing gears.
6. The Midfuselage provides a structural interface for the forward fuselage, aft fuselage and wings. It supports the payload bay doors, hinges as well as various Orbiter system components. The Midfuselage provides the structural foundation for the payload bay doors.
7. The Orbital Maneuvering System/Reaction Control System Pods are attached to the upper aft fuselage left and right sides and contain all of the Orbital Maneuvering System (OMS) and Reaction Control System (RCS) propulsion elements that are located at the aft of the Orbiter. (These systems have been explained in the subsystems of space shuttle).
8. The Body Flap provides a thermal shield for the three Space Shuttle Main Engines during re-entry and provides the Orbiter with pitch control trim during atmospheric flight.
9. The Vertical Tail consists of a structural fin surface, a rudder/speed brake surface, a tip and a lower trailing edge. The Vertical Tail provides aerodynamic stability for the Orbiter during flight, and its rudder can be split into two halves to act as a speed brake during landing
10. The Aft Fuselage consists of an outer shell, thrust structure and internal secondary structure. The Aft Fuselage supports and interfaces with the orbital maneuvering system/reaction control system pods.
The Aft Fuselage also supports and interfaces with the wings, midfuselage, Orbiter/External Tank rear attachments, Space Shuttle Main Engines, aft heat shield, body flap, vertical tail and two pre-launch umbilical panels.
The Aft Fuselage outer shell allows access to systems installed within the structure. The Aft Fuselage thrust structure supports the three Space Shuttle Main Engines and their hardware. The internal secondary structure houses hardware and wiring for auxiliary power unit, hydraulics, ammonia boiler and flash evaporator systems.