WINGS IN ORBIT: SCIENTIFIC AND ENGINEERING LEGACIES OF THE SPACE SHUTTLE NASA

SOFTBOUND BOOK in ENGLISH by NATIONAL AERONAUTICS AND SPACE ADMINISTRATION (WAYNE HALE, HELEN LANE, GAIL CHAPLINE, KAMLESH LULLA)

ISBN 148028596X, ISBN-13 9781480285965

A MAGNIFICENT FLYING MACHINE

THE HISTORICAL LEGACY (MAJOR MILESTONES, THE ACCIDENTS – CHALLENGER & COLUMBIA, NATIONAL SECURITY MISSIONS)

THE SPACE SHUTTLE AND ITS OPERATIONS (THE SPACE SHUTTLE, PROCESSING THE SHUTTLE FOR FLIGHT, FLIGHT OPERATIONS, EXTRAVEHICULAR ACTIVITY EVA OPERATIONS AND ADVANCEMENTS, HOW THE SHUTTLE BUILT THE INTERNATIONAL SPACE STATION ISS)

ENGINEERING INNOVATIONS (PROPULSION, THERMAL PROTECTION SYSTEM, MATERIALS AND MANUFACTURING, AERODYNAMICS & FLIGHT DYNAMICS, AVIONICS, NAVIGATION, INSTRUMENTATION, COMPUTER SOFTWARE, STRUCTURAL DESIGN, ROBOTICS, AUTOMATION, SYSTEMS ENGINEERING FOR LIFE CYCLE OF COMPLEX SYSTEMS)

MAJOR SCIENTIFIC DISCOVERIES (THE SPACE SHUTTLE AND THE GREAT OBSERVATORIES – HUBBLE, ATMOSPHERIC OBSERVATIONS AND EARTH IMAGING, MAPPING THE EARTH: RADARS & TOPOGRAPHY, ASTRONAUT HEALTH & PERFORMANCE, THE SPACE SHUTTLE – EXPANDING THE FRONTIERS OF BIOLOGY, MICROGRAVITY RESEARCH, SPACE ENVIRONMENTS)

INDUSTRIES AND SPIN-OFFS

SHUTTLE CARRIER AIRCRAFT

ENTERPRISE TEST VEHICLE

DESIGN AND DEVELOPMENT

FROM PROTOTYPE TO FLIGHT

OPERATIONAL HISTORY

APPROACH AND LANDING TESTS

RESEARCH AND DEVELOPMENT FLIGHTS

THE OPERATIONAL ERA

CHALLENGER ACCIDENT 1986 / INVESTIGATION

OV-101 ENTERPRISE

OV-102 COLUMBIA

OV-103 CHALLENGER

OV-104 ATLANTIS

OV-105 DISCOVERY

TECHNICAL DESCRIPTION:

ORBITER DESCRIPTION, FORWARD FUSELAGE, CREW MODULE, FLIGHT DECK, MID-DECK, EQUIPMENT BAY, MID-FUSELAGE, WINGS, AFT-FUSELAGE, BODY FLAP, VERTICAL STABILIZER, MAIN ENGINES, POWER SYSTEMS, ENVIRONMENTAL CONTROLS, THERMAL PROTECTION SYSTEM, AVIONICS, LANDING GEAR, BRAKES, EXTERNAL TANK, SOLID ROCKET BOOSTERS, RANGE SAFETY SYSTEM, OPERATIONAL FLIGHT SEATS, RMS CONTROLS AND DISPLAYS, ROTATION HAND CONTROL, PRIVACY CURTAINS, PAYLOAD BAY TELEVISION CAMERA AND FLOODLIGHTS, WASTE COLLECTION, RESCUE CONFIGURATION, AIRLOCK, INSTRUMENT EQUIPMENT LOCATIONS, ENVIRONMENTAL CONTROL AND LIFE SUPPORT SYSTEM, S-BAND RADIOS, ORBITTER ANTENNAS, THERMAL BARRIERS, RCC WING LEADING EDGE, RCC NOSE CAP, INTERNAL STRUCTURE COMPONENTS, PAYLOAD BAY DOORS, DOOR DEPLOYABLE RADIATOR, ACTIVE PAYLOAD RETENTION SYSTEM, MECHANICAL ARM, AERODYNAMIC SURFACES, ELEVON CONTRUCTION, BODY FLAP, VERTICAL TAIL, NOSE LANDING GEAR, MAIN LANDING GEAR, WHEEL BRAKE ASSEMBLY, LANDING GEAR DOOR CONSTRUCTION, EXTERNAL TANK CUTAWAY DWG, EXT TANK RANGE SAFETY LINEAR SHAPED CHARGES, REACTION CONTROL SYSTEM, EXTERNAL TANK-ORBITER DISCONNECT VALVES, ORBITER/ EXT TANK UMBILICAL, SRB CUTAWAY DRAWING, SRB RECOVERY PROCEDURE, SRB JOINT DETAILS, SRB SEPARATION SYSTEM, AUXILLIARY POWR UNIT, WATER SPRAY UNIT, APU EXHAUST AND WATER BOILER VENT, ORBITER VENT DOORS, VENTING SYSTEM)

LAUNCH FACILITIES

KENNEDY SPACE CENTER

SHUTTLE LANDING FACILITY SLF

VEHICLE ASSEMBLY BUILDING VAB

ORBITER PROCESSING FACILITY OPF

ORBITER MODIFICATION AND REFURBISHMENT OMRF

LAUNCH CONTROL CENTER LCC

TRANSPORTABLE EQUIPMENT

LAUNCH PAD 39A& 39B

VANDENBERG AFB LAUNCH SITE VLS

MISSION CONTROL HOUSTON

MAJOR SPACE SHUTTLE CONTRACTS

APPROACH AND LANDING TEST FLIGHTS

SIGNIFICANT ORBITER MILESTONES

CONCEPTUAL DESIGN CONFIGURATION DATA

SHUTTLE ABORT REGIONS

STS MISSION DATA

COUNTDOWN MILESTONES

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Additional Information from Internet Encyclopedia

The Space Shuttle is a partially reusable low Earth orbital spacecraft system that was operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development.[10] The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. In addition to the prototype whose completion was cancelled, five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011, launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST); conducted science experiments in orbit; and participated in construction and servicing of the International Space Station. The Shuttle fleet's total mission time was 1322 days, 19 hours, 21 minutes and 23 seconds.

Shuttle components include the Orbiter Vehicle (OV) with three clustered Rocketdyne RS-25 main engines, a pair of recoverable solid rocket boosters (SRBs), and the expendable external tank (ET) containing liquid hydrogen and liquid oxygen. The Space Shuttle was launched vertically, like a conventional rocket, with the two SRBs operating in parallel with the OV's three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, and the ET was jettisoned just before orbit insertion, which used the orbiter's two Orbital Maneuvering System (OMS) engines. At the conclusion of the mission, the orbiter fired its OMS to deorbit and reenter the atmosphere. The orbiter then glided as a spaceplane to a runway landing, usually to the Shuttle Landing Facility at Kennedy Space Center, Florida or Rogers Dry Lake in Edwards Air Force Base, California. After landing at Edwards, the orbiter was flown back to the KSC on the Shuttle Carrier Aircraft, a specially modified Boeing 747.

The first orbiter, Enterprise, was built in 1976, used in Approach and Landing Tests and has no orbital capability. Four fully operational orbiters were initially built: Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in mission accidents: Challenger in 1986 and Columbia in 2003, with a total of fourteen astronauts killed. A fifth operational (and sixth in total) orbiter, Endeavour, was built in 1991 to replace Challenger. The Space Shuttle was retired from service upon the conclusion of Atlantis's final flight on July 21, 2011. The U.S. has since relied on the Russian Soyuz spacecraft to transport astronauts to the International Space Station, pending the Commercial Crew Development and Space Launch System programs with flights to begin in the 2020s.

In September 1966, NASA and the Air Force released a joint study concluding that a new vehicle was required to satisfy their respective future demands, and that a partially reusable system would be the most cost-effective solution.[12]:164 The head of the NASA Office of Manned Space Flight, George Mueller, announced the plan for a reusable shuttle on August 10, 1968. NASA issued a Request for Proposal (RFP) for designs of the Integrated Launch and Re-entry Vehicle (ILRV), which would later become the Space Shuttle. Rather than award a contract based upon initial proposals, NASA announced a phased approach for the Space Shuttle contracting and development; Phase A was a request for studies completed by competing aerospace companies, Phase B was a competition between two contractors for a specific contract, Phase C involved designing the details of the spacecraft components, and Phase D was the production of the spacecraft.

In December 1968, NASA created the Space Shuttle Task Group to determine the optimal design for a reusable spacecraft, and issued study contracts to General Dynamics, Lockheed, McDonnell Douglas, and North American Rockwell. In July 1969, the Space Shuttle Task Group issued a report that determined the Shuttle would support a space station, launch, service, and retrieve satellites, and support short-duration crewed missions. The report also created three classes of a future reusable shuttle: Class I would have a reusable orbiter mounted on expendable boosters, Class II would use stage-and-a-half staging, and Class III would have both a reusable orbiter and a reusable booster. In September 1969, the Space Task Group, under leadership of Vice President Spiro Agnew, issued a report calling for the development of a space shuttle to bring people and cargo to low Earth orbit (LEO), as well as a space tug for transfers between orbits and the Moon, and a reusable nuclear stage for deep space travel.

After the release of the Space Shuttle Task Group report, many aerospace engineers favored the Class III, fully reusable design because of perceived savings in hardware costs. Max Faget, a NASA engineer who had worked to design the Mercury capsule, patented a design for a two-stage fully recoverable system with a straight-winged orbiter mounted on a larger straight-winged booster.[16][17] The Air Force Flight Dynamics Laboratory argued that a straight-wing design would not be able to withstand the high thermal and aerodynamic stresses during reentry, and would not provide the required cross-range capability. Additionally, the Air Force required a larger payload capacity than Faget's design allowed. In January 1971, NASA and Air Force leadership decided that a reusable delta-wing orbiter mounted on an expendable propellant tank would be the optimal design for the Space Shuttle.

After establishing the need for a reusable, heavy-lift spacecraft, NASA and the Air Force began determining the design requirements of their respective services. The Air Force expected to launch large satellites into a polar orbit, and that the Space Shuttle have a 4.6-meter (15 ft) by 18-meter (60 ft) foot payload bay, 1,800-kilometer (1,100 mi) cross-range, and the capacity to lift 29,000-kilogram (65,000 lb) to an easterly low Earth orbit, and 18,000-kilogram (40,000 lb) into polar orbit. NASA evaluated the F-1 and J-2 engines from the Saturn rockets, and determined that they were insufficient for the requirements of the Space Shuttle, and in July 1971, it issued a contract to Rocketdyne to begin development on the RS-25 engine.

NASA reviewed 29 potential designs for the Space Shuttle. NASA determined that a design with two side boosters should be used, and the boosters should be reusable to reduce costs. NASA and the Air Force elected to use solid-propellant boosters because of the lower costs and the ease of refurbishing them for reuse after they landed in the ocean. In January 1972, President Richard Nixon approved the Shuttle, and NASA decided on its final design in March. In August 1972, NASA awarded the contract to build the orbiter to North American Rockwell, the solid-rocket booster contract to Morton Thiokol, and the external tank contract to Martin Marietta.

On June 4, 1974, Rockwell began construction on the first shuttle, Orbiter Vehicle (OV)-101, which would later be named Enterprise. Enterprise was designed as a test vehicle, and did not include engines or heat shielding. Construction was completed on September 17, 1976, and Enterprise was moved to Edwards AFB to begin testing.[12]:173[18] Rockwell also constructed the Main Propulsion Test Article (MPTA)-098, which was later fit with RS-25 engines and tested at the National Space Technology Laboratory (NSTL). Rockwell conducted structural tests on Structural Test Article (STA)-099 to determine the effect of aerodynamic stresses.

The beginning of the development of the RS-25 Space Shuttle Main Engine was delayed for nine months while Pratt & Whitney challenged the contract that had been issued to Rocketdyne. The first engine was completed in March 1975, after issues with developing the first throttlable, reusable engine. During engine testing, the RS-25 experienced multiple nozzle failures, as well as broken turbine blades. Despite the problems during testing, NASA ordered the nine RS-25 engines needed for its three orbiters under construction in May 1978.

NASA experienced significant delays in the development of the Space Shuttle's thermal protection system. Previous NASA spacecraft had used ablative heat shields, but those could not be reused. NASA chose to use ceramic tiles for thermal protection, as the shuttle could then be constructed of lightweight aluminum, and the tiles could be individually replaced as needed. Construction began on Columbia on March 27, 1975, and it was delivered to the Kennedy Space Center (KSC) on March 25, 1979. At the time of its arrival at the KSC, Columbia still had 6,000 of its 30,000 tiles remaining to be installed. However, many of the tiles that had been originally installed had to be replaced, requiring two years of installation before Columbia could fly.

On January 5, 1979, NASA commissioned a second orbiter. Later that month, Rockwell began converting STA-099 to OV-099, later named Challenger. On January 29, 1979, NASA ordered two additional orbiters, OV-103 and OV-104, which were named Discovery and Atlantis. Construction of OV-105, later named Endeavour, began in February 1982, but NASA decided to limit the Space Shuttle fleet to four orbiters in 1983. After the loss of Challenger, NASA resumed production of Endeavour in September 1987.

After it arrived at Edwards AFB, Enterprise underwent flight testing with the Shuttle Carrier Aircraft, a Boeing 747 that had been modified to carry the orbiter. In February 1977, Enterprise began the Approach and Landing Tests and underwent captive flights, where it remained attached to the Shuttle Carrier Aircraft for the duration of the flight. On August 12, 1977, Enterprise conducted its first glide test, where it detached from the Shuttle Carrier Aircraft and landed at Edwards AFB.[12]:173–174 After four additional flights, Enterprise was moved to the Marshall Space Flight Center on March 13, 1978. Enterprise underwent shake tests in the Mated Vertical Ground Vibration Test, where it was attached to an external tank and solid rocket boosters, and underwent vibrations to simulate the stresses of launch. In April 1979, Enterprise was taken to the Kennedy Space Center, where it was attached to an external tank and solid rocket boosters, and moved to LC-39. Once installed at the launch pad, the Space Shuttle was used to verify the proper positioning of launch complex hardware. Enterprise was taken back to California in August 1979, and later served in the development of the SLC-6 at Vandenberg AFB in 1984.

On November 26, 1980, Columbia was mated with its external tank and solid-rocket boosters, and was moved to LC-39 on December 29, 1980. The first Space Shuttle mission, STS-1, would be the first time NASA performed a crewed first-flight of a spacecraft. On April 12, 1981, the Space Shuttle launched for the first time, and was piloted by John Young and Robert Crippen. During the two-day mission, Young and Crippen tested equipment on board the shuttle, and found several of the ceramic tiles had fallen off the top side of the Columbia. NASA coordinated with the Air Force to use satellites to image the underside of Columbia, and determined there was no damage. Columbia reentered the atmosphere on April 14, and landed at Edwards AFB.

NASA conducted three additional test flights with Columbia in 1981 and 1982. On July 4, 1982, STS-4, flown by Ken Mattingly and Henry Hartsfield, landed at Edwards AFB. President Ronald Reagan and his wife Nancy met the crew, and delivered a speech. After STS-4, NASA declared the Space Shuttle operational.

The Space Shuttle was the first operational orbital spacecraft designed for reuse. Each Space Shuttle orbiter was designed for a projected lifespan of 100 launches or ten years of operational life, although this was later extended. At launch, it consisted of the orbiter, which contained the crew and payload, the external tank (ET), and the two solid rocket boosters (SRBs).

Responsibility for the Shuttle components was spread among multiple NASA field centers. The Kennedy Space Center was responsible for launch, landing and turnaround operations for equatorial orbits (the only orbit profile actually used in the program), the U.S. Air Force at the Vandenberg Air Force Base was responsible for launch, landing and turnaround operations for polar orbits (though this was never used), the Johnson Space Center served as the central point for all Shuttle operations, the Marshall Space Flight Center was responsible for the main engines, external tank, and solid rocket boosters, the John C. Stennis Space Center handled main engine testing, and the Goddard Space Flight Center managed the global tracking network.

The orbiter had design elements and capabilities of both a rocket and an aircraft to allow it to launch vertically and then land as a glider. Its three-part fuselage provided support for the crew compartment, cargo bay, flight surfaces, and engines. The rear of the orbiter contained the Space Shuttle Main Engines (SSME), which provided thrust during launch, as well as the Orbital Maneuvering System (OMS), which allowed the orbiter to achieve, alter, and exit its orbit once in space. Its double-delta wings were 18-meter (60 ft) long, and were swept 81° at the inner leading edge and 45° at the outer leading edge. Each wing had an inboard and outboard elevon to provide flight control during reentry, along with a flap located between the wings, below the engines to control pitch. The orbiter's vertical stabilizer was swept backwards at 45°, and contained a rudder that could split to act as a speed brake. The vertical stabilizer also contained a two-part drag parachute system to slow the orbiter after landing. The orbiter used retractable landing gear with a nose landing gear and two main landing gear, each containing two tires. The main landing gear contained two brake assemblies each, and the nose landing gear contained an electro-hydraulic steering mechanism.

Four operational OVs were originally built. Following the construction of Columbia (OV-102) and the conversion of Challenger (OV-099) to a flyable spacecraft, Discovery (OV-103) and Atlantis (OV-104) were ordered in January 1979. After the Challenger disaster in January 1986, NASA ordered a fifth OV, Endeavour (OV-105) in July 1987. Endeavour was primarily built from structural spares that were created during the construction of Discovery and Atlantis.

Crew compartment

The crew compartment comprised three decks, and was the pressurized, habitable area on all Space Shuttle missions. The cockpit consisted of two seats for the commander and pilot, as well as an additional two to four seats for crew members. The mid-deck is located below the cockpit, and is where the galley and crew bunks were set up, as well as three or four crew member seats. The mid-deck contained the airlock, which could support two astronauts on an extravehicular activity (EVA), as well as access to pressurized research modules. An equipment bay was below the mid-deck, which stored environmental control and waste management systems.[14]:60–62[23]:365–369 To ensure the cabin would be comfortable for the crew, designers created a full-sized cardboard mock-up of the cabin. Astronauts would then mimic their daily activities inside of the mock-up. Each time they knocked up against a corner, technicians would remove the part of the mock-up that had gotten in the astronauts' way until there were no more collisions and the cabin was deemed to be comfortable.

On the first four Shuttle missions, astronauts wore modified U.S. Air Force high-altitude full-pressure suits, which included a full-pressure helmet during ascent and descent. From the fifth flight, STS-5, until the loss of Challenger, the crew wore one-piece light blue nomex flight suits and partial-pressure helmets. After the Challenger disaster, the crew members wore the Launch Entry Suit (LES), a partial-pressure version of the high-altitude pressure suits with a helmet. In 1994, the LES was replaced by the full-pressure Advanced Crew Escape Suit (ACES), which improved the safety of the astronauts in an emergency situation. Columbia originally had modified SR-71 zero-zero ejection seats installed for the ALT and first four missions, but these were disabled after STS-4 and removed after STS-9.

The flight deck was the top level of the crew compartment, and contained the flight controls for the orbiter. The commander sat in the front left seat, and the pilot sat in the front right seat, with two to four additional seats set up for additional crew members. The instrument panels contained over 2,100 displays and controls, and the commander and pilot were both equipped with a heads-up display (HUD) and a Rotational Hand Controller (RHC) to gimbal the engines during powered flight and fly the orbiter during unpowered flight. Both seats also had rudder controls, to allow rudder movement in flight and nose-wheel steering on the ground. The orbiter vehicles were originally installed with the Multifunction CRT Display System (MCDS) to display and control flight information. The MCDS displayed the flight information at the commander and pilot seats, as well as at the after seating location, and also controlled the data on the HUD. In 1998, Atlantis was upgraded with the Multifunction Electronic Display System (MEDS), which was a glass cockpit upgrade to the flight instruments that replaced the eight MCDS display units with 11 multifunction colored digital screens. MEDS was flown for the first time in May 2000 on STS-98, and the other orbiter vehicles were upgraded to it. The aft section of the flight decked contained windows looking into the payload bay, as well as an RHC to control the Remote Manipulator System during cargo operations. Additionally, the aft flight deck had monitors for a closed-circuit television to view the cargo bay.

The mid-deck was located underneath the flight deck. It contained the crew equipment storage, as well as the sleeping and hygiene stations for the crew. The mid-deck contained seats for three crewmembers (Columbia's mid-deck could seat four) during launch and landing procedures. The mid-deck contained a port-side hatch that crew used for entry and exit while on Earth. Additionally, each orbiter was originally installed with an internal airlock in the mid-deck. The airlock was replaced with an external airlock on Discovery, Atlantis, and Endeavour to improve docking with Mir and the ISS.

Flight systems

The orbiter was equipped with an avionics system to provide information and control during atmospheric flight. Its avionics suite contained three microwave scanning beam landing systems, three gyroscopes, three TACANs, three accelerometers, two radar altimeters, two barometric altimeters, three attitude indicators, two Mach indicators, and two Mode C transponders. During reentry, the crew deployed two air data probes once they were travelling slower than Mach 5. The orbiter had three inertial measuring units (IMU) that it used for guidance and navigation during all phases of flight. The orbiter contains two star trackers to align the IMUs while in orbit. The star trackers are deployed while in orbit, and can automatically or manually align on a star. In 1991, NASA began upgrading the inertial measurement units with an inertial navigation system (INS), which provided more accurate location information. In 1993, NASA flew a GPS receiver for the first time aboard STS-51. In 1997, Honeywell began developing an integrated GPS/INS to replace the IMU, INS, and TACAN systems, which first flew on STS-118 in August 2007

While in orbit, the crew primarily communicated using one of four S band radios, which provided both voice and data communications. Two of the S band radios were phase modulation transceivers, and could transmit and receive information. The other two S band radios were frequency modulation transmitters, and were used to transmit data to NASA. As S band radios can operate only within their line of sight, NASA used the Tracking and Data Relay Satellite System and the Spacecraft Tracking and Data Acquisition Network ground stations to communicate with the orbiter throughout its orbit. Additionally, the orbiter deployed a high-bandwidth Ku band radio out of the cargo bay. The Ku radio could also utilized as a rendezvous radar. The orbiter was also equipped with two UHF radios for communications with air traffic control and astronauts conducting extravehicular activity.

Although the orbiter could not be flown without a crew, its fly-by-wire control system was entirely reliant on its main computer, the Data Processing System (DPS). The DPS controlled the flight controls and thrusters on the orbiter vehicle, as well as the ET and SRBs during launch. The DPS consisted of five general purpose computers (GPC), two magnetic tape mass memory units (MMUs), and the associated sensors to monitors the Space Shuttle components. The original GPC used was the IBM AP-101B, which used a separate central processing unit (CPU) and inputer/output processor (IOP), and non-volatile solid-state memory. From 1991 to 1993, the orbiter vehicles were upgraded to the AP-101S, which improved the memory and processing capabilities, and reduced the volume and weight of the computers by combining the CPU and IOP into a single unit. Four of the GPCs were loaded with the Primary Avionics Software System (PASS), which was Space Shuttle-specific software that provided control through all phases of flight. During ascent, maneuvring, reentry, and landing, the four PASS GPCs functioned identically to produce quadruple redundancy, and would error check their results. In case of a software error that would cause erroneous reports from the four PASS GPCs, a fifth GPC ran the Backup Flight System, which used a different program and could control the Space Shuttle through ascent, orbit, and reentry, but could not support an entire mission. The five GPCs were separated in three separate bays within the mid-deck to provide redundancy in the event of a cooling fan failure. After achieving orbit, the crew would switch some of the GPCs functions from guidance, navigation, and control (GNC) to systems management (SM) and payload (PL) to support the operational mission.

Space Shuttle missions typically brought a portable general support computer (PGSC) that could integrate with the orbiter vehicle's computers and communication suite, as well as monitor scientific and payload data. Early missions brought the Grid Compass, one of the first laptop computers, as the PGSC, but later missions brought Apple and Intel laptops.

Payload bay

The payload bay comprised most of the orbiter vehicle's fuselage, and provided the cargo-carrying space for the Space Shuttle's payloads. It was 18-meter (60 ft) long and 4.6-meter (15 ft) wide, and was the could accommodate cylindrical payloads up to 15 feet (4.6 m) in diameter. These measurements were chosen specifically to accommodate the KH-9 HEXAGON spy satellite operated by the National Reconnaissance Office.[33] Two payload bay doors hinged on either side of the bay, and provided a relatively airtight seal to protect payloads from heating during launch and reentry. Payloads were secured the in the payload bay to the attachment points on the longerons. The payload bay doors served an additional function as radiators for the orbiter vehicle's heat, and were opened upon reaching orbit for heat rejection.

The orbiter could be used in conjunction with a variety of add-on components depending on the mission. This included orbital laboratories (Spacelab, Spacehab), boosters for launching payloads farther into space (Inertial Upper Stage, Payload Assist Module), and other functions, such as provided by Extended Duration Orbiter, Multi-Purpose Logistics Modules, or Canadarm (RMS). An upper stage called Transfer Orbit Stage (Orbital Science Corp. TOS-21) was also used once with the orbiter.[34] Other types of systems and racks were part of the modular Spacelab system —pallets, igloo, IPS, etc., which also supported special missions such as SRTM.[35] To limit the fuel conseumption while the orbiter vehicle was docked at the ISS, the Station-to-Shuttle Power Transfer System (SSPTS) was installed on Discovery and Endeavour. The SSPTS was first used on STS-118, and allowed the orbiter vehicle to be power by the ISS's power supply.

Remote Manipulator System

The Remote Manipulator System (RMS), also known as Canadarm, was a mechanical arm attached to the cargo bay. It could be used to grasp and manipulate payloads, as well as serve as a mobile platform for astronauts conducting an Extravehicular activity (EVA). The RMS was built by the Canadian company Spar Aerospace, and was controlled by an astronaut inside the orbiter's flight deck using their windows and closed-circuit television. The RMS allowed for six-degrees of freedom, and had six joints located at three points along the arm. The original RMS could deploy or retrieve payloads up to 65,000 pounds (29,000 kg), which was later improved to 586,000 pounds (270,000 kg)

Spacelab

In 1973, European ministers met in Belgium to authorize the Spacelab program, which was a European multidisciplinary orbital space laboratory that flew in the payload bay.[39][35] Spacelab provided a modular, pressurized laboratory for use in orbit. The Spacelab module contained two 2.7 m (9 ft) segments that were mounted in the aft end of the payload bay to maintain the center of gravity during flight. Astronauts entered the Spacelab module through a 2.7 m (8.72 ft) or 5.8 m (18.88 ft) tunnel that connected to the airlock. The Spacelab equipment was primarily stored in pallets, which provided storage for both experiments as well as computer and power equipment. Spacelab hardware was flown on 28 missions through 1999, and studied subjects including astronomy, microgravity, radar, and life sciences.[35] Spacelab hardware also supported missions such as Hubble Space Telescope (HST) servicing and space station resupply.[35] STS-2 and STS-3 provided testing, and the first full mission was Spacelab-1 (STS-9) launched on November 28, 1983.[35] Germany funded the Spacelab missions D1 and D2. In addition to the European Space Agency, Japan also partially funded research during the SL-J mission.

Three RS-25 engines were mounted on the orbiter's aft fuselage in a triangular pattern. The engine nozzles could gimbal ±10.5° in pitch, and ±8.5° in yaw during ascent to change the direction of their thrust to steer the Shuttle. The orbiter structure was made primarily from aluminum alloy, although the engine structure was made primarily from titanium alloy.

The RS-25 engines had several improvements to enhance reliability and power. During the development program, Rocketdyne determined that the engine was capable of safe reliable operation at 104% of the originally specified thrust. To keep the engine thrust values consistent with previous documentation and software, NASA kept the original specified thrust as 100%, but had the RS-25 operate at higher thrust. RS-25 upgrade versions were denoted as Block I and Block II. 109% thrust level was achieved with the Block II engines in 2001. The normal maximum throttle was 104 percent, with 106% or 109% used for mission aborts.

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This publication authoritatively documents the many accomplishments of NASA's Space Shuttle Program from its origins to the present. Beginning with a Foreword by astronauts John Young and Robert Crippen, this compelling book provides clear, accurate, and authentic accounts from NASA's best subject matter experts, including aerospace engineers who worked with the shuttle program, and leading experts from the science and academic communities. The book captures the passion of those who devoted their energies to the program's success for more than three decades. It focuses on their science and engineering accomplishments, the rich history of the program, and the shuttle as an icon in U.S. history. Its comprehensive overview of the shuttle and its accomplishments, combined with its lucid prose, makes Wings in Orbit a unique resource for anyone interested in the history and achievements of American space exploration." The first great age of space exploration culminated with the historic lunar landing in July 1969. Following that achievement, the space policymakers looked back to the history of aviation as a model for the future of space travel. The Space Shuttle was conceived as a way to exploit the resources of the new frontier. Using an aviation analogy, the shuttle would be the Douglas DC-3 of space. That aircraft is generally considered to be the first commercially successful air transport. The shuttle was to be the first commercially successful space transport. This impossible leap was not realized, an unrealistic goal that appears patently obvious in retrospect, yet it haunts the history of the shuttle to this day. Much of the criticism of the shuttle originates from this overhyped initial concept. In fact, the perceived relationship between the history of aviation and the promise of space travel continues to motivate space policymakers. In some ways, the analogy that compares space with aviation can be very illustrative. If the first crewed spacecraft of 1961 are accurately the analog of the Wright brothers' first aircraft, the Apollo spacecraft of 1968 should properly be compared with the Wright brothers' 1909 "Model B"-their first commercial sale. The "B" was the product of 6 years of tinkering, experimentation, and adjustments, but were only two major iterations of aircraft design. In much the same way, Apollo was the technological inheritor of two iterations of spacecraft design in 7 years. The Space Shuttle of 1981-coming 20 years after the first spaceflights-could be compared with the aircraft of the mid-1920s. In fact, there is a good analogy in the history of aviation: the Ford Tri-Motor of 1928. But here the aviation analogy breaks down. In aviation history, advances are made not just because of the passage of calendar time but because there are hundreds of different aircraft designs with thousands of incremental technology advances tested in flight between the "B" and the Tri-Motor. Even so, the aviation equivalent compression of decades of technological advance does not do justice to the huge technological leap from expendable rockets and capsules to a reusable, winged, hypersonic, cargo-carrying spacecraft. This was accomplished with no intermediate steps. Viewed from that perspective, the Space Shuttle is truly a wonder. No doubt the shuttle is but one step of many on the road to the stars, but it was a giant leap indeed. That is what this book is about: not what might have been or what was impossibly promised, but what was actually achieved and what was actually delivered. Viewed against this background, the Space Shuttle was a tremendous engineering achievement-a vehicle that enabled nearly routine and regular access to space for hundreds of people, and a profoundly vital link in scientific advancement. The vision of this book is to take a clear-eyed look at what the shuttle accomplished and the shuttle's legacy to the world. This book will serve as an excellent reference for building future space vehicles.