Shuttle Reference Manual
The Shuttle Reference Manual, most recently revised in 1988, is an
indepth technical guide to space shuttle equipment and operations. It
was accurate in 1988 and while most of the information provided here
from the manual is still accurate today, some facts may be outdated.
Space Transportation System
- Space Shuttle Program
- The overall shuttle program is called the Space Transportation System.
NASA oversees the program and coordinates flight requirements for
all shuttle missions.
- Space Shuttle Requirements
- A high-level overview of the shuttle's requirements includes basic
specifications and mission profile.
- Launch Sites
- Kennedy Space Center in Florida is the sole shuttle launch site.
However, the Shuttle Reference Manual includes plans for western test
range satellite deployment missions from Vandenberg Air Force Base
in California.
- Background and Status
- A high-level chronological overview of program milestones from 1972
to 1987.
- Mission Profile
- An overview of launch, orbit, and entry profiles is detailed here,
including airspeed, altitude, and vehicle attitude requirements.
- Aborts
- If a problem occurs in the first eight minutes after liftoff, one
of five different abort modes may be used.
- Intact Aborts
- There are four types of intact aborts:
- Abort To Orbit
- Designed to allow the vehicle to achieve a temporary orbit
that is lower than the nominal orbit.
- Abort Once Around
- Designed to allow the vehicle to fly once around the Earth
and make a normal entry and landing.
- Transatlantic Landing
- Designed to permit an intact landing on the other side of
the Atlantic Ocean.
- Return to Launch Site
- Involves flying downrange to dissipate propellant and then
turning around under power to return directly to a landing
at or near the launch site.
- Contingency Abort
- Maintains orbiter integrity for in-flight crew escape if a landing
cannot be achieved at a suitable landing field.
- Orbiter Ground Turnaround
- After landing, the orbiter undergoes postflight processing to secure
its systems, recover payloads and experiments, and prepare it for
its next mission.
Orbiter Manufacturing and Assembly
Orbiter structures were manufactured at various companies under contract
to Rockwell International's Space Transportation Systems Division, Downey,
Calif.
Operational Improvements and Modifications
Many of the changes and upgrades in the space shuttle systems and components
were under way before the 51-L accident as part of NASA's continual
improvement and upgrade program. However, NASA has taken advantage of
the space shuttle program downtime since the accident to accelerate
the testing and integration of these improvements and upgrades as well
as fixes required as a result of the accident.
- Orbiter
- The following identifies the major improvements or modifications
of the orbiter. Approximately 190 other modifications and improvements
were also made.
- Space Shuttle Main Engine Margin Improvement
Program
- As early as 1983, engineers designed modifications to the SSMEs,
improving margin and durability.
- SSME Flight Program
- In the first 25 flights, three off-nominal SSME conditions were
detected. A major upgrade ensured these problems would not be repeated.
- Solid Rocket Motor Redesign
- Based on the recommendations of the "Presidential Commission on
the Space Shuttle Challenger Accident," new design criteria were assessed
and implemented for the solid rocket motors.
Solid Rocket Boosters
- Overview
- Two solid rocket boosters provide the main thrust to lift the space
shuttle off the pad. They are the largest solid-propellant motors
ever flown, the first designed for reuse.
- Hold-Down Posts
- Each SRB has four hold-down posts securing it to the launch platform.
- SRB Ignition
- A sequence of events occurs within a few seconds before launch,
leading up to SRB ignition and liftoff.
- Electrical Power Distribution
- The orbiter supplies power to the SRBs.
- Hydraulic Power Units
- Each SRB has two self-contained independent hydraulic power units.
- Thrust Vector Control
- Each SRB has two hydraulic gimbal actuators that provide the force
and control to gimbal the nozzle for thrust vector control.
- SRB Rate Gyro Assemblies
- Each SRB has two RGAs that provide attitude data to the orbiter
computers during ascent.
- SRB Separation
- Explosive bolts separate the SRBs from the external tank when fuel
has been expended.
- Range Safety System
- The vehicle has three RSSs, one in each SRB and one in the external
tank. If the vehicle violates a launch trajectory red line, the ground
can command them to self-destruct.
- SRB Descent and Recovery
- 295 seconds after they separate from the vehicle, both SRBs fall
into the Atlantic Ocean, where they are recovered for reuse.
External Tank
- Overview
- The largest element of the shuttle vehicle is the external tank.
It supplies fuel and oxidizer to the space shuttle main engines during
launch.
- Liquid Oxygen Tank
- Contains liquid oxygen and delivers it under pressure through a
feed line.
- Intertank
- Houses external tank instrumentation components.
- Liquid Hydrogen Tank
- Delivers a maximum flow of over 47,000 gallons of hydrogen per minute.
- Thermal Protection System
- Consists of sprayed-on foam insulation and premolded ablator materials.
- External Tank Hardware
- Includes valves, fittings, sensors, and umbilical equipment.
- Range Safety System
- Provides for dispersing tank propellants if necessary.
Space Shuttle Coordinate System
The space shuttle coordinate reference system is a means of locating
specific points on the shuttle.
Orbiter Structure
- Overview
- The orbiter structure is deivided into several major sections and
is constructed mostly of aluminum.
- Forward Fuselage
- Consists of the upper and lower fuselage, houses the crew compartment.
- Crew Compartment
- The three-level crew compartment includes the flight deck, middeck,
and equipment bay.
- Airlock
- The middeck airlock is large enough to accommodate two suited astronauts
at once.
- Forward Fuselage and Crew Compartment
Windows
- The orbiter has 11 windows.
- Wing
- An aerodynamic lifting surface that provides conventional lift and
control for the orbiter.
- Midfuselage
- Forms the payload bay area, interfaces with the forward fuselage,
aft fuselage and wings.
- Payload Bay Doors
- Are opened shortly after orbital insertion to provide for vehicle
heat dissipation.
- Aft Fuselage
- Consists of an outer shell, thrust structure and internal secondary
structure.
- Orbital Maneuvering System/Reaction
Control System Pods
- Attached to the aft fuselage, house the OMS/RCS propulsion components.
- Body Flap
- Thermally shields the main engines during entry, provides pitch
control trim during landing approach.
- Vertical Tail
- Consists of a structural fin surface, a rudder, a tip and a lower
trailing edge.
Orbiter Passive Control System
A passive thermal control system helps maintain the temperature of
the orbiter spacecraft, systems and components within their temperature
limits.
Orbiter Purge, Vent and Drain System
The purge, vent and drain system on the orbiter is designed to prevent
accumulation of hazardous gasses and vent compartments.
Orbiter Flight Crew Escape Systems
- Inflight Crew Escape System
- Provided for use only when the orbiter would be in controlled gliding
flight and unable to reach a runway.
- Emergency Egress Slide
- Provides the flight crew with emergency egress through the middeck
side hatch.
- Secondary Emergency Egress
- Overhead window provides the flight crew with a secondary emergency
egress route.
Crew Equipment
- Food System and Dining
- The middeck is equipped with facilities for food stowage, preparation
and dining.
- Shuttle Orbiter Medical System
- Provides medical care in flight for minor illnesses and injuries.
- Operational Bioinstrumentation System
- Provides an electrocardiograph signal for transmission to the ground.
- Radiation Equipment
- Passive and active dosimeters monitor radiation during missions.
- Crew Apparel
- Apparel includes pressure suits and IVA clothing.
- Sleeping Provisions
- Sleeping bags, sleep restraints, and rigid sleep stations are used
on orbit.
- Personal Hygiene Provisions
- A personal hygiene kit is furnished for each crew member.
- Housekeeping
- Supplies and equipment are provided for maintenance of a clean crew
cabin environment.
- Sighting Aids
- Includes binoculars, adjustable mirrors and spotlights.
- Microcassette Recorder
- Used for voice recording of data and for playing prerecorded tapes.
- Photographic Equipment
- Several camera systems are used by the flight crew to document activities
during the mission.
- Wicket Tabs
- Devices used to help crew members activate controls in the dark.
- Reach Aid
- A short adjustable bar used to activate switches out of the crewmember's
reach.
- Restraints and Mobility Aids
- Equipment includes foot restraints, handholds, ladders and handrails.
- Crew Equipment Stowage
- Crew equipment is stowed in lockers with insertable trays.
- Exercise Equipment
- To maintain good cardiovascular health, crew members use a specially
designed treadmill.
- Sound Level Meter
- Measures acoustical noise levels in the crew cabin.
- Air Sampling System
- Air bottles capture ambient atmosphere in the cabin.
Space Shuttle Orbiter Systems
- Thermal Protection System
- Various materials applied to the outer structure protect the orbiter
from excessive heat.
- Overview
- Seven different materials, chosen for their weight efficiency
and stability at high temperatures, are used.
- Reinforced Carbon-Carbon
- RCC protects areas where temperatures exceed 2,300 degrees F
during entry.
- High-Temperature Reusable
Surface Insulation Tiles
- Black tiles are applied on areas where temperatures do not exceed
2,300 degrees F.
- Fibrous Refractory Composite
Insulation Tiles
- Black tiles developed later in the program replace some HRCI
tiles.
- Low-Temperature Reusable Surface Insulation Tiles
- White tiles are used in areas where temperatures do not exceed
1,200 degrees F.
- Advanced Flexible Reusable
Surface Insulation Blankets
- Quilted composite fabric replaced most of the LRSI tiles.
- Felt Reusable Surface Insulation
- Nomex felt blankets are used on the payload bay doors and other
areas where temperatures do not exceed 700 degrees F.
- Thermal Barriers
- Various materials are used to fill in gaps.
- Tile Identification
- Each tile has a unique ID code.
- Flags and Letters
- Flags and letters are painted on.
- Rewaterproofing
- After each flight the orbiter is rewaterproofed.
- Contractors
- List of contractors for the thermal protection system.
- Main Propulsion System
- Along with SRBs, provides velocity increment necessary to reach
orbit.
- Overview
- The main propulsion system includes three main engines, controllers
and supporting equipment.
- Orbiter Main Propulsion System
Helium Subsystem
- Helium is used to purge tanks and actuate valves.
- Main Propulsion System
Propellant Management Subsystem
- Liquid hydrogen and liquid oxygen are fuels used by the system.
- External Tank
- The external tank feeds fuel to the main propulsion system.
- Space Shuttle Main Engines
- The main engines are reusable, high-performance, liquid-propellant
rocket engines with variable thrust.
- Pogo Suppression System
- A pogo suppression system prevents engine thrust oscillation.
- Space Shuttle Main Engine
Controllers
- Each controller operates in conjunction with other components
to provide a self-contained system for engine control, checkout
and monitoring.
- Malfunction Detection
- There are three separate means of detecting malfunctions within
the main propulsion system.
- Orbiter Hydraulic Systems
- Three hydraulic systems supply pressure to the main propulsion
system, providing thrust vector control and actuating engine valves
on each SSME.
- Thrust Vector Control
- Ascent thrust vector control directs thrust of the main engines
and SRBs to control attitude and trajectory from liftoff through
second-stage ascent.
- Helium, Oxidizer and
Fuel Flow Sequence
- The complete sequence begins several hours before launch and
ends after main engine cutoff.
- Main Propulsion System
Contractors
- List of contractors.
- Orbiter/External Tank Separation System
- Includes system components on both sides of the separation.
- Overview
- When the external tank separates from the orbiter, several components
act at once for a clean disconnect.
- 17-inch Disconnect
- Mated pairs of disconnects contain valves that allow propellant
to flow until time for ET separation.
- External Tank Separation
System
- The external tank is separated from the orbiter at three structural
attach points.
- Orbiter Umbilical Doors
- After external tank jettison, doors close the umbilical cavities.
- Orbital Maneuvering System
- The orbital maneuvering system provides the thrust for orbit insertion,
circularization, orbit transfer, rendezvous, and deorbit.
- Overview
- The OMS is housed in two independent pods located on each side
of the orbiter's aft fuselage.
- Helium Pressurization
- The OMS system uses helium to pressurize fuel tanks.
- Propellant Storage and Distribution
- OMS propellant tanks enable the orbiter to reach a 1,000-foot-per-second
velocity change.
- Engine Bipropellant Valve
Assembly
- Each OMS engine receives pressure-fed propellants at its bipropellant
valve assembly.
- Engine Thrust Chamber Assembly
- The thrust chamber is where the fuel and oxidizer react in the
injector.
- OMS Thrusting Sequence
- The OMS thrusting sequence commands the OMS engines on or off
and commands the engine purge function.
- Engine Thrust Vector Control
System
- The engine TVC system consists of a gimbal ring assembly, two
gimbal actuator assemblies, and two gimbal actuator controllers.
- Thermal Control
- OMS thermal control is achieved by insulation in the OMS pods
and strip heaters.
- OMS-RCS Interconnect
- OMS propellant can be used to operate the Reaction Control System.
- OMS-to-RCS Gauging Sequence
- The OMS-to-aft-RCS propellant quantities are calculated by burn
time integration.
- Abort Control Sequences
- The abort control sequence software manages OMS and RCS configuration
and thrusting periods during ascent aborts.
- OMS Engine Fault Detection and
Identification
- The OMS engine FDI function detects and identifies off-nominal
performance of the OMS engine.
- OMS Gimbal Actuator FDI
- The OMS gimbal actuator FDI detects and identifies off-nominal
performance of the pitch and yaw gimbal actuators of the OMS engines.
- Reaction Control System
- The RCS units provide the thrust for pitch, yaw and roll maneuvers
and for small velocity changes along the orbiter axis.
- Overview
- The forward and aft RCS systems consist of helium storage tanks,
pressure systems, propellant systems, and thermal control.
- Pressurization System
- Gaseous helium supplies pressure to the fuel and oxidizer tanks.
- Propellant System
- A system of tanks, lines and valves distributes propellant to
the RCS thrusters.
- RCS Quantity Monitor
- Onboard computers calculate the usable percent of fuel and oxidizer
in each RCS module.
- Engine Propellant Feed
- Isolation valves control the amount of propellant being fed
to each RCS module.
- RCS Engines
- Each RCS engine contains a fuel and oxidizer valve, injector
head assembly, combustion chamber, nozzle and electrical junction
box.
- Heaters
- Heaters maintain propellant and pod temperatures within safe
operating ranges.
- RCS Jet Selection
- Based on crew commands, the onboard computers direct RCS burns.
- Electrical Power System
- EPS subsystems work together to provide electrical power to the
vehicle during all mission phases.
- Overview
- The EPS consists of three subsystems: power reactant storage
and distribution, fuel cell power plants, and electrical power
distribution and control.
- Power Reactant Storage and
Distribution
- Cryogenic hydrogen and oxygen are stored in specially-equipped
tanks.
- Fuel Cell Power Plants
- The fuel cells are located under the payload bay area and in
the forward portion of the orbiter's midfuselage.
- Electrical Power Distribution
and Control
- The EPDC subsystem distributes 28-volt dc electrical power and
generates and distributes 115-volt, three-phase, 400-hertz ac
electrical power to all of the space shuttle systems' electrical
equipment throughout all mission phases.
- Environmental Control and Life Support
System
- ECLSS systems interact to provide a habitable environment for the
flight crew and cooling or heating for various orbiter systems and
components.
- Overview
- The ECLSS consists of atmosphere and water treatment and thermal
systems.
- Crew Compartment Cabin
Pressurization
- The cabin is pressurized to 14.7 psia and maintained at an average
80-percent nitrogen and 20-percent oxygen mixture by the air revitalization
system.
- Cabin Air Revitalization
- There are five independent air loops in the cabin.
- Water Coolant Loop System
- The WCLS provides thermal conditioning of the crew cabin by
collecting heat at a heat exchanger and transferring it to the
water coolant loops.
- Active Thermal Control System
- The ATCS consists of Freon interchangers, radiators and heat
exchangers to control thermal conditions.
- Supply and Waste Water
- The supply and waste water systems provide water for the flash
evaporator, crew consumption and hygiene.
- Waste Collection System
- The waste collection system is an integrated, multifunctional
system used primarily to collect and process biological wastes
from crew members in a zero-gravity environment.
- Waste Water Tank
- A single waste water tank receives waste water from the ARS
humidity separator and the waste collection system.
- Airlock Support
- The airlock and airlock hatches permit EVA flight crew members
to transfer from the middeck crew compartment into the payload
bay in EMUs without depressurizing the orbiter crew cabin.
- Extravehicular Activity Mobility
Units
- EMU space suits provide the necessities for life support during
space walks.
- Crew Altitude Protection System
- The crew altitude protection system is worn by the flight crew
members during launch and entry.
- Radioisotope Thermoelectric
Generator Cooling and Gaseous Nitrogen Purge for Payloads
- A cooling and purge system is installed in Discovery and Atlantis
to support those payloads with RTGs or gaseous nitrogen purging
requirements.
- Auxiliary Power Units
- The orbiter has three APUs, hydrazine-fueled, turbine driven power
units produce pressure for the vehicle's hydraulic systems.
- Water Spray Boilers
- The water spray boiler system consists of three identical independent
water spray boilers, one per corresponding auxiliary power unit and
hydraulic system.
- Hydraulic System
- The hydraulic system consists of three independent systems, each
providing mechanical shaft power to drive a hydraulic pump.
- Landing Gear System
- Each landing gear includes a shock strut with two wheel and tire
assemblies.
- Overview
- The landing gear system on the orbiter is a conventional aircraft
tricycle configuration consisting of a nose landing gear and a
left and right main landing gear.
- Main Landing Gear Brakes
- Each of the orbiter's four main landing gear wheels has electrohydraulic
disc brakes and an anti-skid system.
- Nose Wheel Steering
- The orbiter nose wheel is steerable after nose wheel touchdown
at landing.
- Caution and Warning System
- Designed to provide the crew with both visual and aural cues when
a system exceeds predefined operating limits.
- Orbiter Lighting System
- The orbiter lighting system provides both interior and exterior
lighting.
- Smoke Detection and Fire
Suppression
- Smoke detection and fire suppression capabilities are provided
in the crew cabin avionics bays, the crew cabin and the Spacelab
pressurized module.
- Payload Deployment and Retrieval
System
- The payload deployment and retrieval system includes the electromechanical
arm that maneuvers a payload from the payload bay of the space
shuttle orbiter to its deployment position and then releases it.
- Payload Retention Mechanisms
- Non-deployable payloads are retained by passive retention devices,
and deployable payloads are secured by motor-driven, active retention
devices.
- Communications
- Ground-based, orbiter and satellite systems are employed to keep
the crew in touch with Mission Control.
- Space Flight Tracking and Data
Network
- Provides tracking, data acquisition and associated support.
- Tracking and Data Relay Satellite
System
- Provides continuous global coverage of Earth-orbiting satellites
at altitudes from 750 miles to about 3,100 miles.
- Orbiter Communications
- Transfers telemetry information, commands, documentation and
voice communications.
- Overview
- Information is transferred through hardline and radio frequency
links.
- S-Band System
- Operates in the S-band portion of the RF spectrum of 1,700
to 2,300 MHz.
- Ku-Band System
- Used only when the orbiter is on orbit.
- Ku-Band Rendezvous
Radar
- Ku-Band system includes a rendezvous radar that skin-tracks
satellites and other rendezvous targets.
- Payload Communication
System
- Used to transfer information between orbiter and its payloads.
- Ultrahigh Frequency
System
- Used as a backup fro S-Band PM and Ku-Band voice communications,
primarily for EVAs.
- Audio System
- Interfaces with caution/warning system, UHF, S-Band, Ku-Band,
and tacan systems.
- Instrumentation
- Several camera systems are used by the flight crew to document
activities during the mission.
- Overview
- Used to collect, route and process information throughout the
orbiter and its payloads.
- Pulse Code Modulation
Master Unit
- Receives data from MDMs and formats them for transmission to
the ground.
- Network Signal Processor
- Responsible for processing and routing commands, telemetry and
voice between the orbiter and the ground.
- Ground Command Interface
Logic
- Also referred to as the ground command interface logic controller.
- General-Purpose Computer
and Communication Interface
- Computers process communication controls and provide a command
path between the ground and orbiter subsystems.
- Master Timing Unit
- A stable crystal-controlled timing source for the orbiter.
- Operational Recorders
- Used for serial recording and dumping of digital voice and PCM
data.
- Payload Recorder
- Records and dumps payload data through S-Band or Ku-Band transmitter.
- Teleprinter
- Interim system designed tro transmit written data from the ground
to the crew.
- Text and Graphics System
- Fax scanner on the ground that sends text and graphics to hard
copier in orbiter.
- Close-Circuit Television
System
- Used to support on-orbit activities that require visual feedback
to the crew.
- Operational Recorders
- Used for serial recording and dumping of digital voice and PCM
data.
- Orbiter Experiments Support
Systems for OV-102 (Columbia)
- Records data obtained through OEX sensors.
- Shuttle Infrared Leeside
Temperature Sensing
- Obtains high-resolution infrared imagery of orbiter surfaces
during atmospheric entry.
- Shuttle Entry Air Data
System
- takes measurements required for precise determination of air
data during launch and landing phases.
- Shuttle Upper Atmosphere
Mass Spectrometer
- Obtains measurements of free-stream density during atmospheric
entry.
- Aerodynamic Coefficient
Identification Package
- A group of sensors palced on the orbiter to obtain experiment
measurements unavailable through the baseline system.
- High-Resolution Accelerometer
Package
- Measures low-level aerodynamic accelerations along the orbiter's
principal axed during re-entry.
- Modular Auxiliary Data
System
- Measures and records selected pressure, temperature, strain,
vibration and event data.
- Avionics Systems
- Controls, or assists in controlling, most of the shuttle systems.
- Overview
- Controls, or assists in controlling, most of the shuttle systems.
- Data Processing System
- The vehicle relies on computerized control and monitoring for
successful performance.
- Software
- DPS software is divided into two major groups: system software
and applications software.
- General-Purpose
Computers
- Five identical computers aboard the orbiter control vehicle
systems.
- Mass Memory Units
- Computing functions for all mission phases requires about
400,000 words of computer memory.
- Multifunction CRT
Display System
- Displays on the flight deck allow onboard monitoring of
systems, software processing and manual control for crew data
and software manipulation.
- Master Timing Unit
- The GPC complex requires an accurate time source because
its software uses GMT to schedule processing.
- Computer Data
Bus Network
- Network is divided into specific groups that perform specific
functions.
- Multiplexers/Demultiplexers
- DPS MDMs convert and format serial digital GPC commands
into separate commands for various vehicle system hardware.
- Master Events Controllers
- Send signalls to arm and safe pyrotechnics during SRB/ET
separation.
- Data Bus Isolation
Amplifiers
- Interfacing devices for the GSE/LPS and SRB MDMs.
- Backup Flight Control
- The fifth GPC, loaded with different software, provides
backup in case primary GPCs fail.
- Guidance, Navigation and Control
- GNC software commands effect vehicle control and provide sensor
data needed to compute these commands.
- Flight Control System
Hardware
- Hard-wired to one of eight flight-critical MDMs.
- Navigational
Aids
- Include IMUS, tacan units, air data probe assemblies, and
more.
- Inertial Measurement
Units
- Consist of an all-attitude, four-gimbal, inertially stabilized
platform.
- Star Trackers
- Two star tracker units are part of the navigation system.
- Crewman Optical
Alignment Sight
- Used if IMU alignment is in error more than 1.4 degrees.
- TACAN
- Determine slant range and magnetic bearing to ground station.
- Air Data System
- Provides information on the movement of the orbiter in the
air mass.
- Microwave Scan
Beam Landing System
- Used during landing phase to determine slant range, azimuth
and elevation to landing runway.
- Radar Altimeter
- Measure absolute altitude from the orbiter to nearest terrain
within beamwidth of orbiter's antennas.
- Accelerometer Assemblies
- Sense vehicle acceleration along lateral and vertical axes.
- Orbiter Rate Gyro
Assemblies
- Used by flight control system to sense roll, pitch and yaw
rates during ascent and entry.
- Solid Rocket
Booster Rate Gyro Assemblies
- Used as feedback to find rate errors from liftoff to SRB
separation.
- Rotational Hand
Controller
- Used by flight crew to gimbal engines and OMS/RCS systems.
- Translational Hand
Controller
- Used for manual control of translation along the longitudinal,
lateral, and vertical axes to control RCS.
- Control Stick Steering
Push Button Light Indicators
- Indicate control stick mode.
- Rudder Pedals
- Command orbiter rotation about the yaw axis by positioning
the rudder during atmospheric flight.
- Speed Brake/Thrust
Controller
- Used during ascent to vary thrust level of main engines;
used during entry to control aerodynamic drag.
- Body Flap Switches
- Provide manual control for positioning body flap during
entry.
- RHC/Panel Enable/Inhibit
- Provide signals to GPCs, prohibiting execution of related
software commands while RHC is active.
- Trim Switches
- Used to move the aerosurfaces in roll, pitch and yaw.
- Aerosurface Servoamplifiers
- Receive commands during atmospheric flight, causing aerosurface
deflections.
- Digital Autopilot
- Composed of several software modules that interpret maneuver
commands and generate commands for the appropriate effectors.
- Rendezvous Thrusting
Maneuvers
- OMS/RCS thrusting periods can be used to correct or modify
the orbit as required.
- Component Locations
- Black boxes are situated in several locations around the
orbiter.
- Dedicated Display Systems
- Provide the flight crew with data required to fly the vehicle
manually or to monitor automatic FCS performance.
- Attitude Director
Indicator
- Provide attitude data, including attitude rates and errors.
- Horizontal Situation
Indicator
- Displays a pictorial view of the vehicle's position.
- Alpha Mach Indicator
- Display vehicle angle of attack.
- Altitude/Vertical
Velocity Indicator
- Display vertical acceleration, vertical velocity, barometric
altitude and radar altitude.
- Surface Position
Indicator
- Displays actual and commanded positions of elevons, body
flap, rudder, aileron and speed brake.
- Flight Control
System Push Button Indicators
- Transmit moding requests to digital autopilot.
- RCS Command
Lights
- Indicate RCS jet comands by axis and direction.
- G-Meter
- Senses linear acceleration along the Z axis of the vehicle.
- Head-up Display
- Optical miniprocessor that cues the commander during final
landing approach.
Mission Events Summary
- Terminal Count
- Extends from T minus 20 minutes through SRB ignition.
- First Stage
- Extends from SRB ignition through SRB separation.
- Second Stage
- Begins at SRB separation and extends through main engine cutoff
and ET separation.
- Ascent Abort Modes
- Abort may become necessary if there is a failure that affects vehicle
performance.
- Return-to-Launch-Site
- Designed to allow return of orbiter and crew to KSC launch site.
- Transatlantic Landing
- Available if a main engine fails after last RTLS opportunity,
but before AOA can be accomplished.
- Abort to Orbit
- Used to boost the orbiter to a safe orbital altitude if it is
impossible to reach the planned altitude.
- Abort Once Around
- Vehicle orbits the Earth once and lands at Edwards AFB or KSC.
- Contingency Abort
- Maintains orbiter integrity for in-flight crew escape if landing
cannot be made.
- Manual Thrust Vector Control
- Substitutes inputs from RHC for automatic commands from Guidance.
- Orbit Insertion
- Following MECO, one or two propulsive thrusting periods move the
vehicle to the desired orbital altitude.
- On Orbit
- Guidance, navigation and control during orbit phase.
- On-Orbit Checkout
- The day before deorbit, the crew performs a checkout of systems
used during entry.
- Deorbit
- Phase includes deorbit burn preparation through descent to 400,000
feet.
- Entry
- Phase begins at 400,000 feet and ends at touchdown.
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