Its Operations Flight Operations
Extravehicular Activity Operations and Advancements
Shuttle Builds the International Space Station
The Space Shuttle and Its Operations 53 The Space The Space Shuttle design was remarkable. The idea of “wings in orbit” took concrete shape in the brilliant minds of NASA engineers, and Shuttle the result was the most innovative, elegant, versatile, and highly functional vehicle of its time. The shuttle was indeed an engineering Roberto Galvez marvel on many counts. Accomplishing these feats required the design Stephen Gaylor of a very complex system. Charles Young Nancy Patrick In several ways, the shuttle combined unique attributes not witnessed Dexer Johnson in spacecraft of an earlier era. The shuttle was capable of launching Jose Ruiz like a rocket, reentering Eart h’s atmosphere like a capsule, and flying like a glider for a runway landing. It could rendezvous and dock precisely, and serve as a platform for scientific research within a range of disciplines that included biotechnology and radar mapping. The shuttle also performed satellite launches and repairs, bestowing an almost “perpetual yout h” upon the Hubble Space Telescope through refurbishments.
The most impressive product that resulted from the shuttl e’s capabilities and contributions is the International Space Station—a massive engineering assembly and construction undertaking in space.
No other crewed spacecraft to date has replicated these capabilities. The shuttle has left an indelible mark on our society and culture, and will remain an icon of space exploration for decades to come.
54 The Space Shuttle and Its Operations What Was the winged vehicle for cross-range platforms, interplanetary probes, capability for re-entry into Earth’s Department of Defense payloads, and Space Shuttle? atmosphere and the ability to land a components/modules for the assembly heavyweight payload. of the International Space Station (ISS). Physical Characteristics These four components provided the The shuttle lift capability or payload The Space Shuttle was the most shuttle with the ability to accomplish decreased with increased operational complex space vehicle design of its a diverse set of missions over its altitude or orbit inclination because time. It was comprised of four main flight history. The Orbiter’s heavy more fuel was required to reach the components: the External Tank (ET); cargo/payload carrying capability, along higher altitude or inclination. with the crew habitability and three Space Shuttle Main Engines; Shuttle lift capability was also limited flexibility to operate in space, made two Solid Rocket Boosters (SRBs); by total vehicle landing weight— this vehicle unique. Because of its lift and the Orbiter vehicle. It was the different limits for different cases capability and due-East inclination, the first side-mounted space system (nominal or abort landing). An abort shuttle was able to launch a multitude dictated by the need to have a large landing was required if a system failure of satellites, Spacelab modules, science
Space Shuttle Launch Configuration
Space Shuttle Main Engine SoSolid Rocket Boosterer
The Space Shuttle and Its Operations 55 during ascent caused the shuttle not to a landing speed of about 346 km/hr liquid hydrogen and the other for the have enough energy to reach orbit or (21 5 mph) was 1 hour and 5 minutes. storage of liquid oxygen. The hydrogen was a hazard to crew or mission. Abort tank, which was the bigger of the two During re-entry, the Orbiter was landing sites were located around the internal tanks, held 102,737 kg essentially a glider. It did not have world, with the prime abort landing sites (226,497 pounds) of hydrogen. The any propulsion capability, except for being Kennedy Space Center (KSC) in oxygen tank, located at the top of the the Reaction Control System thrusters Florida, Dryden Flight Research Center ET, held 61 9,1 60 kg (1 ,365, 01 0 pounds) required for roll control to adjust its on the Edwards Air Force Base in of oxygen. Both tanks provided the fuel trajectory early during re-entry. California, and Europe. to the main engines required to provide Management of the Orbiter energy the thrust for the vehicle to achieve a The entire shuttle vehicle, fully from its orbital speed was critical safe orbit. During powered flight and loaded, weighed about 2 million kg to allow the Orbiter to reach its ascent to orbit, the ET provided about (4.4 million pounds) and required a desired runway target. The Orbiter’s 180,000 L/min (47,000 gal/min) of combined thrust of about 35 million limited cross-range capability of about hydrogen and about 67,000 L/min newtons (7.8 million pounds-force) 1,480 km (800 nautical miles) made (1 8,000 gal/min) of oxygen to all three to reach orbital altitude. Thrust was management of the energy during Space Shuttle Main Engines with a provided by the boosters for the first final phases of re-entry close to the 6-to -1 mixture ratio of liquid hydrogen 2 minutes and the main engines for ground—otherwise called terminal to liquid oxygen. the approximately 8 minutes and area energy management—critical 30 seconds ascent required for the for a safe landing. vehicle to reach orbital speed at the Solid Rocket Boosters requisite altitude range of 185 to about The Orbiter performed as a glider 590 km (1 00 to 320 nautical miles). during re-entry, thus its mass properties The two SRBs provided the main had to be well understood to ensure that thrust to lift the shuttle off the launch Once in orbit, the Orbital Maneuvering the Flight Control System could control pad. Each booster provided about System engines and Reaction Control the vehicle and reach the required 14.7 meganewtons (3,300,000 System thrusters were used to perform landing site with the right amount of pounds-force) of thrust at launch, and all orbital operations, Orbiter energy for landing. One of the critical they were only ignited once the three maneuvers, and deorbit. Re-entry components of its aerodynamic flight main engines reached the required required orbital velocity decelerations was to ensure that the Orbiter center of 104.5% thrust level for launch. of about 330 km/hr (204 mph) gravity was correctly calculated and Once the SRBs were ignited, they depending on orbital altitude, which entered into the Orbiter flight design provided about 72% of the thrust caused the Orbiter to slow and fall process. Because of the tight center of required of the entire shuttle at liftoff back to Earth. gravity constraints, the cargo bay and through the first stage, which The Orbiter Thermal Protection System, payloads were placed in the necessary ended at SRB separation. which covered the entire vehicle, cargo bay location to protect the down The SRB thrust vector control system provided the protection needed to weight and center of gravity of the enabled the nozzles to rotate, allowing survive the extreme high temperatures Orbiter for landing. Considering the the entire shuttle to maneuver to the experienced during re-entry. Primarily Orbiter’s size, the center of gravity box required ascent trajectory during friction between the Orbiter and the was only 91 cm (36 in.) long, 5 cm first stage. Two minutes after launch, Earth’s atmosphere generated (2 in.) wide, and 5 cm (2 in.) high. the spent SRBs were jettisoned, temperatures ranging from 927°C having taken the vehicle to an altitude (1 ,700°F) to 1,600°C (3,000°F). The External Tank of about 45 km (28 miles). Not only highest temperatures experienced were were the boosters reusable, they were on the wing leading edge and nose cone. The ET was 46.8 m (1 53.6 ft) in length also the largest solid propellant motors The time it took the Orbiter to start with a diameter of 8.4 m (27.6 ft), in use then. Each measured about its descent from orbital velocity of which made it the largest component 45.4 m (1 49 ft) long and about 3.6 m about 28 ,1 60 km/hr (1 7,500 mph) to of the shuttle. The ET contained two (1 2 ft) in diameter. internal tanks—one for the storage of
56 The Space Shuttle and Its Operations External Tank
Liquid Oxygen Feedline
Liquid Hydrogen Tank Anti-vortex Repressurization Line Baf es Liquid Oxygen Tank Repressurization Line
Liquid Hydrogen Tank
Solid Rocket Booster Forward Attachment Inter Tank Anti-slosh Baf es Gaseous Oxygen Vent Valve and Liquid Oxygen Tank Fairing
Solid Rocket Boosters
Avionics Three Aft Attach Struts Systems Tunnel (External Tank attach ring)
Aft Segment With Nozzle Aft Booster Case Stiffener Rings Separation Motor
Thrust Vector Actuators Aft Exit Cone
The Space Shuttle and Its Operations 57 Space Shuttle Main Engines (492,000 pounds-force) at vacuum machinery comprised of high- and throughout the entire 8 minutes and low-pressure fuel and oxidizer pumps, After SRB separation, the main engines 30 seconds of powered flight. The engine controllers, valves, etc. The provided the majority of thrust required engine nozzle by itself was 2.9 m engines were under constant control for the shuttle to reach orbital velocity. (9.4 ft) long with a nozzle exit diameter by the main engine controllers. These Each main engine weighed about of 2.4 m (7.8 ft). Due to the high heat consisted of an electronics package 3,200 kg (7,000 pounds). With a total generated by the engine thrust, each mounted on each engine to control length of 4.3 m (1 4 ft), each engine, engine contained 1,082 tubes throughout engine operation under strict and critical operating at the 104.5% power level, its entire diameter, allowing circulation performance parameters. The engines provided a thrust level of about 1. 75 of liquid hydrogen to cool the nozzle ran at 104.5% performance for much meganewtons (394,000 pounds-force) during powered flight. The main of the entire operation, except when at sea level and about 2.2 meganewtons engines were a complex piece of they were throttled down to about
Space Shuttle Main Engine
Low-pressure High-pressure Oxidizer Oxidizer Turbopump Turbopump
Main Injector Low-pressure Fuel Turbopump
High-pressure Fuel Turbopump Controller
Main Combustion Chamber
58 The Space Shuttle and Its Operations could be configured for a maximum crew size of seven astronauts, including their required equipment James Thompson, Jr. to accomplish the mission objectives. Space Shuttle Main Engine project The flight deck contained the Orbiter manager (1974-1982). cockpit and aft station where all the Deputy NASA administrator (1989-1991). vehicle and systems controls were located. The crew used six windows in the forward cockpit, two windows “A major problem we had to solve overhead, and two windows looking for the Space Shuttle Main Engine aft for orbit operations and viewing. was called rotary stability subsynchronous whorl. After numerous theories and The middeck was mostly the crew suggestions on turbo machinery, Joe Stangler at Rocketdyne and his team came accommodations area, and it housed up with the vortex and vaporizing theory down in the passages. He proposed all the crew equipment required to putting a paddle in the ﬂow stream and killing the vortex. Even though I thought live and work in space. The middeck also contained the three avionic bays Joe’s theory was crazy, 2 weeks before the program review they had success. where the Orbiter electronic boxes Government, industries, and universities all contributed to its success.” were installed. Due to their limited power generation capability, the Orbiter fuel cells consumables (power generation cryogenics) provided 72% during first stage to preclude about 23.8 m (78 ft). The cargo/payload mission duration capability on the having the vehicle exceed structural carrying capacity was limited by the order of about 12 to 14 days, dependent limits during high dynamic pressure as 18.3-m- (60-ft)-long by 4.6-m- (1 5-ft)- on vehicle configuration. well as close to main engine shutdown wide payload bay. The cargo/payload In 2006, NASA put into place the to preclude the vehicle from exceeding weighed up to 29,000 kg (65,000 Station-to-Shuttle Power Transfer 3 gravitational force (3 g) limits. pounds), depending on the desired System, which allowed the ISS to orbital inclination. The Orbiter payload The only manual main engine control provide power to the Orbiter vehicle, bay doors, which were constructed of capability available to the crew was thereby allowing the Orbiter to graphite epoxy composite material, were the manual throttle control, which have a total mission duration of 18.3 m (60 ft) in length and 4.5 m (1 5 ft) allowed the crew to decrease engine about 16 days. The Orbiter in diameter and rotated through an angle performance from 104.5% to a level configuration (amount of propellant of 175 degrees. A set of radiator panels, of 72% if required for vehicle control. loaded in the forward and aft affixed to each door, dissipated heat The main engines had the capability propellant tanks, payload mounting from the crew cabin avionic systems. to gimbal about 10.5 degrees up and hardware in the payload bay, loading down and 8.5 degrees to either side to The first vehicle, Columbia, was the of cryogenic tanks required for power change the thrust direction required heaviest Orbiter fabricated due to generation, crew size, etc.) was for changes in trajectory parameters. the installation of additional test adjusted and optimized throughout instrumentation required to gather data the pre-mission process. on vehicle performance. As each Orbiter Because of its payload size and Orbiter was fabricated, the test instrumentation robotic arm capability, the Orbiter was deleted and system changes The Orbiter was the primary component could be configured to perform as a implemented, resulting in each of the shuttle; it carried the crew platform for different cargo/payload subsequent vehicle being built lighter. members and mission cargo/payload hardware configurations. In the total hardware to orbit. The Orbiter was about The Orbiter crew cabin consisted of 132 Space Shuttle missions (as of 37.1 m (1 22 ft) long with a wingspan of the flight deck and the middeck and October 2 01 0) over a period of 29 years,
The Space Shuttle and Its Operations 59 the Orbiter deployed a multitude of The Orbiter was the only fully sustained a system failure and satellites for Earth observation and reusable component of the shuttle could not be repaired. Even telecommunications; interplanetary system. Each Orbiter was designed though certified for 100 missions, probes such as Galileo/Jupiter and certified for 100 space missions Discovery, Atlantis, and Endeavour spacecraft and Magellan/Venus Radar and required about 5 months, once completed 39, 32, and 25 missions, Mapper; and great observatories that it landed, to service the different respectively, by October 2 01 0. included the Hubble Space Telescope, systems and configure the payload Challenger flew 10 missions and Compton Gamma Ray Observatory, bay to support requirements for Columbia flew 28 missions before and Chandra X-ray Observatory. The its next mission. NASA replaced their loss on January 28, 1986, and Orbiter even functioned as a science the components only when they February 1, 2003, respectively. platform/laboratory; e.g., Spacelab, Astronomy Ultraviolet Telescope, US Microgravity Laboratory, US The Orbiter Microgravity Payload, etc. Aside from the experiments and satellite deployments the shuttle performed, its most important accomplishment was the delivery and assembly of the ISS.
Monomethylhydrazine and Space Shuttle Reusability Nitrogen Tetroxide Tanks All components of the Space Shuttle Rudder and vehicle, except for the ET, were Speed Brake designed to be reusable flight after S
flight. The ET, once jettisoned from the Orbiter, fell to Earth where atmospheric heating caused the tank to break up Main Engines (3 total) over the ocean.
The SRBs, once jettisoned from the Maneuvering Engines tank, parachuted back to the ocean (2 total) where they were recovered by special ships and brought back to KSC. Aft Control With their solid propellant spent, the Thrusters boosters were de-stacked and shipped back to aerospace and defense company Thiokol in Utah for
refurbishment and reuse. The SRBs were thoroughly inspected after every mission to ensure that the components were not damaged and could be refurbished for another flight. Any Body Flap damage found was either repaired or the component was discarded.
60 The Space Shuttle and Its Operations T Typical Flight Profile
Nominal Orbit about 278 km (150 nautical miles) On-orbit Operations
Orbital Maneuvering System Deorbit Burn
Orbital Maneuvering System Orbital Insertion
Entry Interface Elevation 122 km 400,000 ft) External Tank Separation ( Mission Time approx. 0:08:50 About 7,963 km Main Engine Cutoff (4,300 nautical miles) Mission Time approx. 0:08:32 from Landing Site Elevation 117 km (383,000 ft)
Solid Rocket Booster Separation Mission Time approx. 0:02:02 Landing Elevation 50 km Speed 364 kph (163,000 ft) (196 knots or 226 mph)
Solid Rocket Booster Landing External Tank Impact Indian Ocean Mission Time approx. 0:07:13
Liftoff from Kennedy R Space Center, Florida 00:00:00 = Hours:Minutes:Seconds
Space Radiators Payload: Long-duration Exposure Facility (inside doors) Manipulator Arm
Forward Control Thrusters
Electrical System Fuel Cells Main Landing Gear
The Space Shuttle and Its Operations 61 Automation, Autonomy, about 400,000 instructions per second safe continuation of the mission. and Redundancy and did not have a hard disk drive The loss of the second box still allowed capability. These computers were the function to work properly with The Space Shuttle was the first space replaced in April 1991 (first flight was only two remaining boxes, which vehicle to use the fly-by-wire STS-37) with an upgraded model that subsequently allowed for safe re-entry computerized digital flight control had about 2.5 times the memory capacity and landing of the Orbiter. Other system. Except for manual switch and three times the processor speed. critical functions were designed with throws for system power-up and certain To protect against corrupt software, the only triple redundancy, which meant valve actuations, control of the Orbiter general purpose computers had a that fail-operational/fail-safe reliability systems was through the general backup computer that operated with a allowed the loss of two of the boxes purpose computers installed in the completely different code independent before the function was lost. forward avionics bay in the middeck. of the Primary Avionics Software The avionics systems redundancy System. This fifth computer, called the Each Orbiter had five hardware- management scheme was essentially Backup Flight System, operated in the identical general purpose computers; controlled via computer software that background, processing the same four functioned as the primary means to operated within the general purpose critical ascent/re-entry functions in case control the Orbiter systems, and one computers. This scheme was to select the four general purpose computers was used as a backup should a software the middle value of the avionics failed or were corrupted by problems anomaly or problem cause the loss of components when the systems had with their software. The Backup Flight the four primary computers. During three or four avionics boxes executing System could be engaged at any ascent and re-entry—the critical phases the same function. On loss of the first moment only by manual crew of flight—four general purpose box, the redundancy management command, and it also performed computers were used to control the scheme would down mode to the oversight and management of Orbiter spacecraft. The primary software, called “average value” of the input received noncritical functions. For the first 132 the Primary Avionics Software System, from the functioning boxes. Upon the flights of the Space Shuttle Program, was divided into two major systems: second box failure, the scheme would the Backup Flight System computer system software, responsible for further down mode to the “use value,” was never engaged and, therefore, was computer operation, synchronization, which essentially meant that the not used for Orbiter control. and management of input and output function was performed by using input operations; and applications software, The overall avionics system architecture data from only one remaining unit in which performed the actual duties that used the general purpose the system. This robust avionics required to fly the vehicle and operate computer redundancy was developed architecture allowed the loss of the vehicle systems. with a redundancy requirement for avionics redundancy within a function Even though simple in their architecture fail-operational/fail-safe capability. without impacting the ability of the compared to today’s computers, the These redundancy schemes allowed for Orbiter to perform its required mission. general purpose computers had a the loss of redundancy in the avionics complex redundancy management systems and still allowed continuation Maneuverability, Rendezvous, scheme in which all four primary of the mission or safe landing of the and Docking Capability computers were tightly coupled together Orbiter. All re-entry critical avionics and processed the same information functions, such as general purpose Maneuverability at the same time. This tight coupling computers, aero surface actuators, rate was achieved through synchronization gyro assemblies, accelerometer The Orbiter was very maneuverable and steps and cross-check results of their assemblies, air data transducer could be tightly controlled in its pointing processes about 440 times per second. assemblies, etc., were designed with accuracy, depending on the objective it The original International Business four levels of redundancy. This meant was trying to achieve. The Orbiter Machines computers had only about that each of these functions was controllability and pointing capability 424 kilobytes of memory each. The controlled by four avionic boxes that was performed by the use of 44 Reaction central processing unit could process performed the same specific function. Control System thrusters installed both The loss of the first box allowed for in the forward and the aft portions of the
62 The Space Shuttle and Its Operations Reaction Control Thrusters and Orbital Maneuvering System
Right Aft Propulsion System Pod (14 jets, 1 Orbital Maneuvering System engine)
Reaction Control System Jets
Orbital Maneuvering System Engines
Reaction Control System Jets Jets
Left Aft Propulsion System Pod Forward Reaction (14 jets, 1 Orbital Control System Maneuvering (16 jets) System engine)
Orbital Maneuvering System Jets Engine
Reaction Control System Jets
vehicle. Of the 44 thrusters, six were were vernier thrusters. The thrusters The general purpose computers also Reaction Control Systems and each were installed on the Orbiter in such a controlled the tight Orbiter attitude had a thrust level of only 111 newtons way that both the rotational and the and pointing capability via the Orbiter (25 pounds-force). The remaining translational control was provided to Digital Auto Pilot—a key piece of 38 thrusters were considered primary each of the Orbiter’s six axes of control application software within the thrusters and each had a thrust level of with each axis having either two or computers. During orbit operations, 3,825 newtons (860 pounds-force). three thrusters available for control. the Digital Auto Pilot was the primary means for the crew to control Orbiter The total thruster complement was The Orbital Maneuvering System pointing by the selection of different divided between the forward thrusters provided propulsion for the shuttle. attitude and attitude rate deadbands, located forward of the crew cabin, and During the orbit phase of the flight, it which varied between +/ -1 .0 and the aft thrusters located on the two was used for the orbital maneuvers 5.0 degrees for attitude and +/-0.02 and Orbital Maneuvering System pods in needed to achieve orbit after the Main 0.2 deg/sec for attitude rate. The Digital the tail of the Orbiter. The forward Propulsion System had shut down. Auto Pilot could perform three-axis thrusters (total of 16) consisted of It was also the primary propulsion automatic maneuver, attitude tracking, 14 primary thrusters and two vernier system for orbital transfer maneuvers and rotation about any axis or body thrusters. Of the 28 thrusters in the aft, and the deorbit maneuver. vector. Crew interface to the Digital 24 were primary thrusters and four
The Space Shuttle and Its Operations 63 Auto Pilot was via the Orbiter cathode The final stage of rendezvous into the shuttle guidance, navigation, ray tubes/keyboard interface, which operations—proximity operations— and control software. Instead, data allowed the crew to control parameters began with the Orbiter’s arrival within were displayed on and controlled by in the software. With very accurate thousands of meters (feet) of the target a laptop computer mounted in the aft control of its orientation, the Orbiter orbital position. During proximity cockpit. This laptop hosted software could provide a pointing capability to operations, the crew used their highest called the Rendezvous Proximity any part of the celestial sky as required fidelity sensors (laser, radar, or direct Operations Program that displayed to accomplish its mission objectives. measurement out the window with a the Orbiter’s position relative to the camera) to obtain the target vehicle’s target for increased crew situational Rendezvous and Docking relative position. The crew then awareness. This display was used transitioned to manual control and extensively by the commander to The shuttle docked to, grappled, used the translational hand controller manually fly the vehicle from 61 0 m deployed, retrieved, and otherwise to delicately guide the Orbiter in for (2,000 ft) to docking. serviced a more diverse set of orbiting docking or grappling operations. objects than any other spacecraft in This assembly of hardware and history. It became the world’s first The first rendezvous missions targeted software aptly met the increased general purpose space rendezvous satellite objects less massive than the accuracy required by delicate docking vehicle. Astronauts retrieved payloads shuttle and grappled these objects with mechanisms and enabled crews to pilot no larger than a refrigerator and docked its robotic arm. During the proximity the massive shuttle within amazing to targets as massive as the ISS, despite operations phase, the commander only tolerances. In fact, during the final the shuttle being designed without had a docking camera view and 0.9 m (3 ft) of docking with the ISS, specific rendezvous targets in mind. accompanying radar information to the Orbiter had to maintain a 7.62-cm In fact, the shuttle wasn’t designed guide the vehicle. Other astronauts (3-in.) lateral alignment cylinder and to physically dock with anything; it aimed payload bay cameras at the target the closing rate had to be controlled was intended to reach out and grapple and recorded elevation angles, which to within 0.02 m/sec (0.06 ft/sec). objects with its robotic arm. were charted on paper to give the The commander could control this commander awareness of the Orbiter’s with incredibly discrete pulses of the A rendezvous period lasted up to 4 days position relative to the target. Once the Reaction Control System thrusters. and could be divided into three phases: commander maneuvered into a position Both the commander and the pilot ground targeted; on-board targeted; and where the target was above the payload were trained extensively in the art of human-piloted proximity operations. bay, a mission specialist grappled the shuttle proximity operations, learning The first phase began with launch into a target with the robotic arm. This method techniques that allowed them to lower orbit, which lagged the target proved highly reliable and applicable to pilot the Orbiter to meet tolerances. vehicle. The Orbiter phased toward the a wide array of rendezvous missions. The shuttle was never meant to be target vehicle due to the different piloted to this degree of accuracy, but orbital rates caused by orbital altitude. Shuttle rendezvous needed a new innovative engineering and training Mission Control at Johnson Space strategy to physically dock with large made these dockings uneventful and Center tracked the shuttle via ground vehicles: the Russian space station Mir even routine. assets and computed orbital burn and the ISS. Rendezvous with larger parameters to push the shuttle higher space stations required more precise The success of shuttle rendezvous toward the target vehicle. As the shuttle navigation, stricter thruster plume missions was remarkable considering neared the target, it transitioned to limitations, and tighter tolerances its operational complexity. Spacecraft on-board targeting using radar and star during docking operations. New tools rendezvous is an art requiring the trackers. These sensors provided such as the laser sensors provided highly scripted choreography of navigation data that allowed on-board highly accurate range and range rate hardware systems, astronauts, and computers to calculate subsequent information for the crew. The laser was members of Mission Control. It is a orbital burns to reach the target vehicle. mounted in the payload bay and its precise and graceful waltz of billions data were routed into the shuttle cabin of dollars of hardware and human but could not be incorporated directly decision making.
64 The Space Shuttle and Its Operations Post-Columbia-Accident Inspection System
The Orbiter Boom Sensor System inspects Area of Inspection the wing leading edge. This system was built for inspections after the Columbia accident (STS-107 ).
Sensor STS-88 (1998) Endeavour’s Shuttle Robotic Arm grapples the Boom Russian Module Zarya for berthing onto the International Space Station (ISS) Node 1, thus beginning the assembly sequence for the ISS. Robotic Arm/Operational Capability The Canadian Space Agency provided the Shuttle Robotic Arm. It was designed, built, and tested by Spar Aerospace Ltd., a Canadian Company. The electromechanical arm measured about 15 m (50 ft) long and 0.4 m (1 5 in.) in diameter with a six-degree- of-freedom rotational capability, and it consisted of a manipulator arm that was under the control of the crew via displays and control panels located in the Orbiter aft flight deck. The Shuttle Robotic Arm was comprised of six joints that corresponded roughly to the joints of a human arm and could handle a payload weighing up to 29,000 kg (65,000 pounds). An end effector was used to grapple a payload or any other fixture and/or component that had a grapple fixture for handling by the arm.
The Space Shuttle and Its Operations 65 Even though NASA used the Shuttle space programs combined, including Extravehicular Mobility Unit Robotic Arm primarily for handling Gemini, Apollo, and Skylab. During The extravehicular mobility unit payloads, it could also be used as a previous programs, EVAs focused was a fully self-sufficient individual platform for extravehicular activity primarily on simple tasks, such as the spacecraft providing critical life (EVA) crew members to attach jettison of expended hardware or support systems and protection from themselves via a portable foot restraint. the collection of geology samples. the harsh space environment. Unlike The EVA crew member, affixed to the The Space Shuttle Program advanced previous suits, the shuttle suit was portable foot restraint grappled by the EVA capability to construction of designed specifically for EVA and was end effector, could then be maneuvered massive space structures, high-strength the cornerstone component for safe around the Orbiter vehicle as required maneuvers, and repair of complicated conduct of EVA during the shuttle era. to accomplish mission objectives. engineering components requiring a It operated at 0.03 kgf/cm 2 (4.3 psi) combination of precision and gentle Following the Return to Flight after the pressure in the vacuum environment handling of sensitive materials and loss of Columbia, the Shuttle Robotic and provided thermal protection for structures. As of October 2 01 0, the Arm was used to move around the interfacing with environments and shuttle accomplished about 157 EVAs Orbiter Boom Sensor System, which components from -73°C (- 100°F) to in 132 flights. Of those EVAs, allowed the flight crew to inspect the 177°C (350°F). It provided oxygen 105 were dedicated to ISS assembly Thermal Protection System around and removed carbon dioxide during and repair tasks. Shuttle EVA the entire Orbiter or the reinforced an EVA, and it supplied battery power crews succeeded in handling and carbon-carbon panels installed on the to run critical life support and ancillary manipulating elements as large as leading edge of the wings. extravehicular mobility unit systems, 9,000 kg (20,000 pounds); relocating including support l ights, cameras, During buildup of the ISS, the Shuttle and installing large replacement and radio. The suit, which also Robotic Arm was instrumental in the parts; capturing and repairing failed provided crew members with critical handling of modules carried by the satellites; and performing surgical-like feedback on system operations Orbiter—a task that would not have repairs of delicate solar arrays, rotating during EVA, was the first spacesuit been possible without the use of this joints, and much more. controlled by a computer. robotic capability. The Orbiter’s EVA capability consisted Future space programs will benefit of several key engineering components tremendously from NASA’s EVA Extravehicular Activity and equipment. For a crew member to experience during the shuttle flights. step out of the shuttle and safely enter Capability To ensure success, the goal has the harsh environment of space, that been and always will be to design The Space Shuttle Program provided crew member had to use the integrated for EVAs that are as simple and a dramatic expansion in EVA airlock, an extravehicular mobility unit straightforward as possible. Fewer capability for NASA, including the spacesuit, a variety of EVA tools, and and less-complicated provisions will ability to perform tasks in the space EVA translation and attachment aids be required for EVA interfaces on environment and ways to best protect attached to the vehicle or payload. EVA spacecraft, and functions previously and accommodate a crew member tools consisted of a suite of components thought to require complicated and in that environment. The sheer that assisted in handling and translating automated systems can now rely on number of EVAs performed during cargo, translating and stabilizing at EVA instead. During the shuttle era, the course of the program resulted the work site, operating manual NASA took the training wheels off in a significant increase in knowledge mechanisms, and attaching bolts and of EVA capability and now has a of how EVA systems and EVA crew fasteners, often with relatively precise fully developed and highly efficient members perform. torque requirements. Photo and operational resource in support of television operations provided Prior to the start of the program, a total both scheduled and contingency documentation of the results for future of 38 EVAs were performed by all US EVA tasks. troubleshooting, when necessary.
66 The Space Shuttle and Its Operations Crew Compartment deck, middeck, and utility area. directly below the flight deck, Accommodation for Crew The flight deck, located on the top accommodated up to three additional and Payloads level, accommodated the commander, crew members and included a pilot, and two mission specialists galley, toilet, sleep locations, storage The Orbiter’s crew cabin had a behind them. The Orbiter was lockers, and the side hatch for habitable volume of 71 .5 m 3 (2,525 ft 3) flown and controlled from the entering and exiting the vehicle. and consisted of three levels: flight flight deck. The middeck, located The Orbiter airlock was also located
Flight deck showing the commander and pilot seats, along with cockpit controls.
The Space Shuttle and Its Operations 67 in the middeck area; it allowed Most of the day-to-day mission middeck stowage capability was up to three astronauts, wearing operations took place on the middeck. equivalent to 127.5 middeck lockers in extravehicular mobility unit The majority of hardware required which each locker was about 0.06 m 3 spacesuits, to perform an EVA in for crew members to live, work, and (2 ft 3) in volume. This volume could the vacuum of space. The standard perform their mission objectives was accommodate all required equipment practice was for only two crew stowed in stowage lockers and bags and supplies for a crew of seven for as members to perform an EVA. within the middeck volume. The entire many as 16 days.
Crew compartment middeck conﬁguration showing the forward middeck lockers in Avionics Bay 1 and 2, crew seats, and sleeping bags.
68 The Space Shuttle and Its Operations Performance Capabilities and Limitations Maximum Deploy Capability for Each Vehicle Versus Altitude
Throughout the history of the 50 program, the versatile shuttle vehicle Endeavour 22 48
was configured and modified to t
h Atlantis g accomplish a variety of missions, i The up-mass e 46 W Discovery capability including: the deployment of Earth d Deploy scenarios are a o
l downweight limited of the shuttle observation and communication y 20 44 a below 388 kilometers
P decreased satellites, interplanetary probes, and (210 nautical miles) relative to the 42 scientific observatories; satellite orbital altitude. retrieval and repair; assembly; crew 18 40 ) )
s 0 0 0 0 0 0 0 0 0 0 0 0 0 0 s 0 0 Nautical 5 6 7 8 9 0 1 2 3 4 5 6 7 8 m 0 d rotation; science and logistics resupply 0 a 0 n 0 1 1 1 1 1 2 2 2 2 2 2 2 2 2 Miles , , r u 1 1 g o x x 8 3 8 4 0 o ( ( l P i of both the Russian space station Mir 7 3 8 4 0 Kilometers K 2 3 3 4 5 and the ISS, and scientific research The Orbiter’s Altitude and operations. Each mission type had its own capabilities and limitations.
Deploying and Servicing Satellites The largest deployable payload launched by the shuttle in the life of the program was the Chandra X-ray Observatory. Deployed in 1999 at an inclination of 28.45 degrees and an altitude of about 2 41 km (1 30 nautical miles), Chandra—and the support equipment deployed with it—weighed 22,800 kg (50,000 pounds). In 1990, NASA deployed the Hubble Space Telescope into a 28.45-degree inclination and a 555-km (300-nautical-mile) altitude. Hubble weighed 13,600 kg (30,000 pounds). Five servicing missions were conducted over the next 19 years to upgrade Hubble’s science instrumentation, thereby enhancing its scientific capabilities. These subsequent servicing missions were essential in
Atlantis’ (STS-125 ) robotic arm lifts Hubble from the cargo bay and is moments away from releasing the orbital observatory to start it on its way back home to observe the universe.
The Space Shuttle and Its Operations 69 correcting the Hubble mirror spherical aberration, thereby extending the operational life of the telescope and upgrading its science capability. Kenneth Reightler Captain, US Navy (retired). Pilot on STS-48 (1991) and Assembling the International STS-60 (1994). Space Station The ISS Node 1/Unity module was “When I think about the legacy launched on STS-88 (1 998), thus beginning the assembly of the ISS, of the Space Shuttle Program which required a total of 36 shuttle in terms of scientiﬁc and missions to assemble and provide engineering accomplishments, logistical support for ISS vehicle the word that comes to mind is operations. As of October 2 01 0, versatility. Each of my ﬂights Discovery had flown 12 missions and involved so many projects and Atlantis and Endeavour had flown 11 missions to the ISS, with each experiments, all involving such a wide variety of science and engineering, mission carrying 12,700 to 18,600 kg it seems almost impossible to catalog them. It is hard to imagine a spacecraft (28,000 to 41 ,000 pounds) of cargo other than the Space Shuttle that could accommodate such an extensive list in the cargo bay and another 3,000 to on just one ﬂight. 4,000 kg (7,000 to 9,000 pounds) of equipment stowed in the crew cabin. “The shuttle’s large cargo bay could hold large, complex structures or many The combined total of ISS structure, small experiments, an amazing variety of experiments. We carried big, intricate logistics, crew, water, oxygen, nitrogen, satellites as well as smaller, simpler ones able to be deployed remotely or and avionics delivered to the station for using robotic and/or human assistance. all shuttle visits totaled more than 603,300 kg (1 ,330,000 pounds). No “For me, as an engineer and a pilot, it was an unbelievable experience to now other launch vehicle in the world could be conducting world-class science in a range of disciplines with the potential deliver these large 4.27-m- (1 4-ft)- to beneﬁt so many people back on Earth, such as experiments designed to diameter by 15.24-m- (50-ft)-long structures or have this much capability. help produce vaccines used to eradicate deadly diseases, to produce synthetic hormones, or to develop countermeasures for the effects of aging. I consider ISS missions required modifications it to be a rare honor and privilege to have operated experiments to which to the three vehicles cited above— Discovery, Atlantis, and Endeavour— so many scientists and engineers had devoted their time, energy, and thought. to dock to the space station. The In some cases, people had spent entire careers preparing for the day when docking requirement resulted in the their experiments could be conducted, knowing that they could only work in Orbiter internal airlock being moved space and there might be only one chance to try. externally in the payload bay. This change, along with the inclusion of the “Each of my ﬂights brought moments of pride and satisfaction in such docking mechanism, added about singular experiences.” 1,500 kg (3,300 pounds) of mass to the vehicle weight.
70 The Space Shuttle and Its Operations A Platform for Scientific Research The Orbiter was configured to accommodate many different types of scientific equipment, ranging from large pressurized modules called Spacelab or Spacehab where the crew conducted scientific research in a shirt-sleeve environment to the radars and telescopes for Earth mapping, celestial observations, and the study of solar, atmospheric, and space plasma physics. The shuttle was often used to deploy and retrieve science experiments and satellites. These science payloads were: deployed using the Shuttle Robotic Arm; allowed to conduct free-flight scientific operations; and then retrieved using the arm for return to Earth for further data analysis. This was a unique capability that only the Orbiter could perform. The Orbiter was also unique because it was an extremely stable platform on which to conduct microgravity research studies in material, fundamental physics, combustion science, crystal growth, and biotechnology that required minimal movement or disturbance from the host vehicle. NASA studied the effect of space adaptation on both humans and animals. Crews of seven worked around the clock conducting research in these pressurized modules/laboratories that were packed with scientific equipment. Much research was conducted with the international community. These missions brought together international academic, industrial, and governmental
The crew from the International Space Station captured this view of STS-97 (2000).
Memories of Wonder
“We have arrived at the base of the launch pad, dressed for the occasion in bright orange pressure suits that ﬁt worse than they look. This is the day! As we enter the service elevator that will take us 193 feet up to the level of the shuttle cabin, we get to appreciate the size of this ship, the mighty solid rockets that hold the gargantuan cozy and safe, alas, our comfort is tempered by the External Tank and the seemingly fragile shuttle craft, poised knowledge of the machine and the job we are about to do. on this unlikely contraption like a gigantic moth, gathering ‘GLS is go for main engine start…’ sounds the familiar strength, for she knows full well where she is going today. female voice. The rumbling below signals the beginning of One by one, between nervous smiles and sheer anticipation, an earthquake. We feel a sudden jolt, the ship is free and we climb into our ship, aided by expert technicians who she ﬂies! We feel the shaking and vibration and the onset of execute their tasks with seamless and clockwork precision, the ‘g’ forces that build up uncomfortably, squeezing our while soothing our minds with carefree conversation. chests and immobilizing our limbs as the craft escapes the The chatter over the audio channels reverberates, pull of the Earth. And in less than 9 minutes, we are in space. unemotional, precise, relentless, and the countdown The view is the most beautiful thing we ever saw and we will clock is our master. We often say that, on launch day, the see this over and over from what is now our new home in the ship seems alive, hissing and creaking with the ﬂow of vacuum of space. The days will pass and this extraordinary the super-cold ﬂuids that give her life. Over the course of vehicle will carry us to our destination…to our destiny. 3 hours, waiting patiently for the hour of deliverance, It has learned to dance in space, with exquisite precision and we have each become one with the Orbiter. The chatter has grace, ﬁrst alone, then with other lonely dates, the Hubble subsided, the technicians have gone. It is just us now, our telescope, the Russian Mir station and the International orange cocoons securely strapped and drawing the sap of Space Station, and when the job was done, it returned to land the mother ship through multiple hoses and cables. It feels softly, majestically, triumphant…and ready to do it all again.”
partners to obtain maximum benefits microgravity. These boxes enabled study diffusion, and combustion and results. The facilities included crew members to handle, transfer, and modules for conducting research on the middeck glove boxes for conducting manipulate experiment hardware and single most important chemical process research and testing science procedures material that were not approved for use in our everyday lives. The shuttle had and for developing new technologies in in the shuttle. There were furnaces to freezers for sample return as well as the
72 The Space Shuttle and Its Operations capability to store large amounts of Spacelab and Spacehab science data for further analysis back on Earth. modules, these payloads were not Scientists used spin tables to conduct accessible by the crew, but rather were biological and physiological research exposed to the space environment. on the crew members. The crew activated and operated these experiments from the pressurized The Orbiter provided all the power confines of the Orbiter flight deck. and active cooling for the laboratories. The Shuttle Radar Topography Mission A typical Spacelab was provided was dedicated to mapping the Earth’s approximately 6.3 kW (8.45 hp) topography between 60 ° North and of power, with peak power as high 58 ° South, including the ocean floor. as 8 .1 kW (1 0.86 hp). To cool the The result of the mission was a three- laboratories’ electronics, the modules dimensional digital terrain map of were tied into the Orbiter’s cooling 90% of the Earth’s surface. The Orbiter system so thermal control of the provided about 10 kW (1 3.4 hp) of payload was the same as thermal power to the Shuttle Radar Topography control for the Orbiter avionics. Mission payload during on-orbit In an effort to share this national operations and all of the cooling for the resource with industry and academia, payloads’ electronics. NASA developed the Get Away Special Program, designed to provide inexpensive access to space for both An Enduring Legacy novices and professionals to explore The shuttle was a remarkable, versatile, new concepts at little risk. In total, complex piece of machinery that over 100 Get Away Special payloads demonstrated our ingenuity for human were flown aboard the shuttle, and exploration. It allowed the United each payload often consisted of States and the world to perform several individual experiments. magnificent space missions for the The cylindrical payload canisters in benefit of all. Its ability to deploy which these experiments were flown satellites to explore the solar system, measured 0. 91 m (3 ft) in length with carry space laboratories to perform a 0.46-m (1 .5-ft) diameter. They were human/biological/material science, and integrated into the Orbiter cargo bay carry different components to assemble on the sill/sidewall and required the ISS were accomplishments that will minimal space and cargo integration not be surpassed for years to come. engineering. The experiments could be confined inside a sealed canister, or the canister could be configured with a lid that could be opened for experiment pointing or deployment. The shuttle was also an extremely accurate platform for precise pointing of scientific payloads at the Earth and celestial targets. These unpressurized payloads were also integrated into the cargo bay; however, unlike the
The Space Shuttle and Its Operations 73 Processing When taking a road trip, it is important to plan ahead by making sure your vehicle is prepared for the journey. A typical road trip on Earth can be the Shuttle for routine and simple. The roadways are already properly paved, service Flight stations are available if vehicle repairs are needed, and food, lodging, and stores for other supplies can also be found. The same, however, could not be said for a Space Shuttle trip into space. The difficulties associated with Steven Sullivan space travel are complex compared with those we face when traveling here. Preparing the Shuttle for Flight Food, lodging, supplies, and repair equipment must be provided for within Ground Processing the space vehicle. Jennifer Hall Peter Nickolenko Vehicle preparation required a large amount of effort to restore the shuttle Jorge Rivera to nearly new condition each time it flew. Since it was a reusable vehicle Edith Stull Steven Sullivan with high technical performance requirements, processing involved a Space Operations Weather tremendous amount of “hands-on” labor; no simple tune-up here. Not only Francis Merceret was the shuttle’s exterior checked and repaired for its next flight, all Robert Scully components and systems within the vehicle were individually inspected and Terri Herst verified to be functioning correctly. This much detail work was necessary Steven Sullivan because a successful flight was dependent on proper vehicle assembly. Robert Youngquist During a launch attempt, decisions were made within milliseconds by equipment and systems that had to perform accurately the first time—there was no room for hesitation or error. It has been said that a million things have to go right for the launch, mission, and landing to be a success, but it can take only one thing to go wrong for them to become a failure.
In addition to technical problems that could plague missions, weather conditions also significantly affected launch or landing attempts. Unlike our car, which can continue its road trip in cloudy, windy, rainy, or cold weather conditions, shuttle launch and landing attempts were restricted to occur only during optimal weather conditions. As a result, weather conditions often caused launch delays or postponed landings.
Space Shuttle launches were a national effort. During the lengthy processing procedures for each launch, a dedicated workforce of support staff, technicians, inspectors, engineers, and managers from across the nation at multiple government centers had to pull together to ensure a safe flight. The whole NASA team performed in unison during shuttle processing, with pride and dedication to its work, to make certain the success of each mission.
74 The Space Shuttle and Its Operations Preparing the the demands of the largest and most The initial six operational missions were complex reusable space vehicle. scheduled to land at DFRC/Edwards Shuttle for Flight Air Force Base because of the safety The end of a mission set in motion margins available on the lakebed a 4- to 5-month process that included Ground Processing runways. Wet lakebed conditions more than 750,000 work hours and diverted one of those landings—Space Imagine embarking on a one-of-a-kind, literally millions of processing steps to Transportation System (ST S)- 3 (1 982)— once-in-a-lifetime trip. Everything prepare the shuttle for the next flight. to White Sands Space Harbor. STS-7 must be exactly right. Every flight of (1 983) was the first mission scheduled to the Space Shuttle was just that way. Landing land at KSC, but it was diverted to A successful mission hinged on ground During each mission, NASA Edwards Air Force Base runways due operations planning and execution. designated several landing sites— to unfavorable Florida weather. The Ground operations was the term used to three in the Continental United States, 10th shuttle flight—STS-41B (1 984)— describe the work required to process three overseas contingency or was the first to land at KSC. the shuttle for each flight. It included transatlanic abort landing sites, and landing-to-launch processing—called a various emergency landing sites Landing Systems “flow”—of the Orbiter, payloads, Solid located in the shuttle’s orbital flight Similar to a conventional airport, the Rocket Boosters (SRBs), and External path. All of these sites had one thing in KSC shuttle landing facility used visual Tank (ET). It also involved many common: the commander got one and electronic landing aids both on important ground systems. Three chance to make the runway. The the ground and in the Orbiter to help missions could be processed at one time, Orbiter dropped like a rock and there direct the landing. Unlike conventional all at various stages in the flow. Each were no second chances. If the target aircraft, the Orbiter had to land perfectly stage had to meet critical milestones or was missed, the result was disaster. the first time since it lacked propulsion throw the entire flow into a tailspin. Kennedy Space Center (KSC) in Florida and landed in a high-speed glide at Each shuttle mission was unique. and Dryden Flight Research Center 343 to 364 km/hr ( 21 3 to 226 mph). The planning process involved creating (DFRC)/Edwards Air Force Base in Following shuttle landing, a convoy a detailed set of mission guidelines, California were the primary landing of some 25 specially designed vehicles writing reference materials and manuals, sites for the entire Space Shuttle or units and a team of about 150 trained developing flight software, generating Program. White Sands Space Harbor in personnel converged on the runway. a flight plan, managing configuration New Mexico was the primary shuttle The team conducted safety checks for control, and conducting simulation pilot training site and a tertiary landing explosive or toxic gases, assisted the and testing. Engineers became masters site in case of unacceptable weather crew in leaving the Orbiter, and at using existing technology, systems, conditions at the other locations. prepared the Orbiter for towing to the and equipment in unique ways to meet Orbiter Processing Facility.
The landing-to- launch ground operations “ﬂow” at Kennedy Space Center prepared each shuttle for its next ﬂight. This 4- to 5-month process required thousands of work hours and millions of individual processing steps. After landing, the Orbiter is moved to the Orbiter Space Shuttle Atlantis landing, STS-129 (2009). Processing Facility.
Landing Orbiter Processing Facility: 120-130 days
The Space Shuttle and Its Operations 75