Shuttle Builds Since its inception, the International Space Station (ISS) was destined to have a close relationship with the Space Shuttle. Conceived for very the International different missions, the two spacecraft drew on each other’s strengths Space Station and empowered each other to achieve more than either could alone. The shuttle was the workhorse that could loft massive ISS elements into space. It could then maneuver, manipulate, and support these pieces John Bacon Melanie Saunders with power, simple data monitoring, and temperature control until the Improvements to the Shuttle pieces could be assembled. The ISS gradually became the port of call Facilitated Assembly of for the shuttles that served it. the International Space Station Lee Norbraten The idea of building a space station dates back to Konstantin Financial Benefits of the Tsiolkovsky’s writings in 1883. A space station would be a small colony Space Shuttle for the United States Melanie Saunders in space where long-term research could be carried out. Visionaries in Psychological Support— many nations offered hundreds of design concepts over the next century Lessons from Shuttle-Mir and a half, and a few simple outposts were built in the late 20th to International Space Station century. The dreams of an enduring international space laboratory Albert Holland coalesced when the shuttle made it a practical reality.

As a parent and child grow, so too did the relationship between the shuttle and the ISS as the fledgling station grew out of its total dependence on the shuttle to its role as a port of call. The ISS soon became the dominant destination in the heavens, hosting vehicles launched from many spaceports in four continents below, including shuttles from the Florida coast.

130 The Space Shuttle and Its Operations Creating the In April 1984, STS-41C deployed Spacelab and Spacehab Flights one of the most important and International Space comprehensive test programs—the Skylab had been an interesting first Station Masterpiece— Long Duration Exposure Facility. step in research but, after the Saturn V STS-32 retrieved the facility in January production ceased, all US space station in Well-planned 1990, giving critical evidence of the designs would be limited to something Increments performance and degradation timeline of similar to the Orbiter’s 4.6-m (1 5-ft.) materials in the low-Earth environment. payload bay diameter. The shuttle Building this miniature world in the It was a treasure trove of data about had given the world ample ways vacuum of space was to be the largest the micrometeoroid orbital debris to evolve concepts of space station engineering challenge in history. It was threat that the ISS would face. NASA’s modules, including a European Space made possible by the incomparable ability to launch such huge test fixtures Agency-built Spacelab and an capabilities of the winged fleet of and to examine them back on Earth American-built Spacehab. Each module shuttles that brought and assembled the after flight added immensely to the rode in the payload bay of the Orbiter. pieces. The space station did not spring engineers’ understanding of the These labs had the same outer diameter into being “out of thin air.” Rather, it technical refinements that would be as subsequent ISS modules. made use of progressively sophisticated necessary for the massively complicated engineering and operations techniques The shuttle could provide the necessary ISS construction. that were matured by the Space Shuttle power, communications, cooling, Program over the preceding 17 years. The next stage in the process would and life support to these laboratories. This evolution began before the first involve an international connection and Due to consumables limits, the shuttle International Space Station (ISS) the coming together of great scientific could only keep these labs in orbit assembly flight ever left the ground— and engineering minds. for a maximum of 2 weeks at a time. or even the drawing board. Through the experience, however,

Early Tests Form a Blueprint NASA ran a series of tests beginning with a deployable solar power wing experiment on Discovery’s first flight (Space Transportation System [STS]-41D in 1984) to validate the construction techniques that would be used to build the ISS. On STS-41G (1 984), astronauts demonstrated the safe capability for in-space resupply of dangerous rocket propellants in a payload bay apparatus. Astronauts practiced extravehicular activity (EVA) assembly techniques for space-station-sized structures in experiments aboard STS-61B (1 985). Several missions tested the performance of large heat pipes in space. NASA explored mobility aids and EVA handling limits during STS-37 (1 991 ). Space Shuttle Atlantis (STS-71) is docked with the Russian space station Mir (1995). At the time, Atlantis and Mir had formed the largest spacecraft ever in orbit. Photo taken from Russian Soyuz vehicle as shuttle begins undocking from Mir. Photo provided to NASA by Russian Federal Space Agency.

The Space Shuttle and Its Operations 131 astronaut crews and ground engineers discovered many issues of loading and Astronaut Shannon Lucid floats in the deploying real payloads, establishing tunnel that connects optimum work positions and locations, Atlantis’ (STS-79 clearances, cleanliness, mobility, [1996]) cabin to the environmental issues, etc. Spacehab double module in the cargo bay. Lucid and her Shuttle-Mir crew mates were already separated In 1994, the funding of the Space from the Russian Station Program passed the US Senate space station Mir by a single vote. Later that year, and were completing end-of-mission Vice President Al Gore and Russian chores before their Deputy Premier Viktor Chernomyrdin return to Earth. signed the agreement that redefined both countries’ space station programs. That agreement also directed the US Striving for Lofty Heights— when the shuttle could angle enough Space Shuttle Program and the Russian And Reaching Them to meet the Russian orbit. space program to immediately hone the complex cooperative operations The biggest effect on the shuttle in Thus, in a cooperative program with required to build the new, larger-than- this merged program was the need to vehicles like Mir (and later the ISS), the dreamed space station. That operations reach a higher-inclination orbit that shuttle had only a tiny “window” each development effort would come through could be accessed from Baikonur day when it could launch. The brief a series of increasingly complex flights Cosmodrome in Kazakhstan. At an chance to beat any intermittent weather of the shuttle to the existing Russian inclination of 51 .6 degrees to the meant that the launch teams and space station Mir. George Abbey, equator, this new orbit for the ISS Mission Control personnel often had to director of Johnson Space Center, would not take as much advantage of wait days for acceptable weather during provided the leadership to ensure the the speed of the Earth’s rotation toward the launch window. As a result of the success of the Shuttle-Mir Program. the East as had originally been planned. frequent launch slips, the Mir and ISS Instead of launching straight eastward control teams had to learn to pack days The Space Shuttle Program immediately and achieving nearly 1,287 km/hour with spontaneous work schedules for engaged Mir engineers and the Moscow (800 mph) from Earth’s rotation, the the station crew on a single day’s Control Center to begin joint operations shuttle now had to aim northward notice. Flexibility grew to become a planning. Simultaneously, engineers to meet the vehicles launched from high art form in both programs. working on the former US-led Space Baikonur, achieving a benefit of only Once the shuttle had launched into the Station Program, called Freedom, went 901 km/hour (560 mph). The speed orbit plane of the Mir, it had to catch to work with their counterparts who difference meant that each shuttle could up to the station before it could dock had been designing and building Mir’s carry substantially less mass to orbit for and begin its mission at the outpost. successor—Mir-II. The new joint the same maximum propellant load. The Normally, rendezvous and docking program was christened the ISS Mir was already in such an orbit, so the would be completed 2 days after Program. Although NASA’s Space constraint was in place from the first launch, giving the shuttle time to make Shuttle and ISS Programs emerged as flight (STS-63 in 1995). flagships for new, vigorous international up any differences between its location cooperation with the former Soviet The next challenge of the 51 .6-degree around the orbit compared to where states, the immediate technical orbit was a very narrow launch window the Mir or ISS was positioned at the challenges were formidable. The Space each day. In performing a rendezvous, time of launch, as well as time for Shuttle Program had to surmount many the shuttle needed to launch close to ground operators to create the precise of these challenges on shorter notice the moment when the shuttle’s launch maneuvering plan that could only be than did the ISS Program. pad was directly in the same flat plane perfected after the main engines cut as the orbit of the target spacecraft. off 8½ minutes after launch. Typically, there were only 5 minutes

132 The Space Shuttle and Its Operations Generally, the plan was to launch The mechanism—called an The Russian wires were designed to then execute the lengthy rendezvous Androgynous Peripheral Docking be soldered into each pin and socket preparation the day after launch. System—became an integral part of while the US connector pins and sockets The shuttle conducted the last stages of the shuttle’s future. It looked a little were all crimped under pressure to their the rendezvous and docking the next like a three-petal artichoke when seen wires in an exact fit. US wire had nickel morning so that a full day could be from the side. US engineers were plating, Russian wire did not. US wire devoted to assembly and cargo transfer. challenged to work scores of details could not be easily soldered into This 2-day process maximized the and unanticipated challenges to Russian connector pins, and Russian available work time aboard the station incorporate this exotic Russian wire could not be reliably crimped into before the shuttle consumables gave apparatus in the shuttle. The bolts that American connector pins. Ultimately, out and the shuttle had to return to held the Androgynous Peripheral unplated Russian wire was chosen Earth. The Mir and ISS teams worked Docking System to the shuttle were and new techniques were certified to in the months preceding launch to manufactured according to Système assure a reliable crimped bond at each place their vehicles in the proper phase International (SI, or metric) units American pin. Even though the in their respective orbits, such that this whereas all other shuttle hardware and Russian system and the shuttle were 2-day rendezvous was always possible. tools were English units. For the first both designed to operate at 28 volts, time, the US space program began to direct current (Vdc), differences in the Arriving at the rendezvous destination create hardware and execute operations grounding strategy required extensive was only the first step of the journey. in SI units—a practice that would discussions and work. The shuttle still faced a formidable become the norm during the ISS era. hurdle: docking. The Space Shuttle Atlantis (STS- 71 ) All connectors in the cabling were arrived at the Mir on June 29, 1995, of Russian origin and were unavailable with the international boundary drawn Docking to Mir in the West. Electrical and data at the crimped interface to a Russian The American side had not conducted interfaces had to be made somewhere. wire in every US connector pin and a docking since the Apollo-Soyuz The obvious solution would be to socket. US 28-Vdc power flowed Test Project of 1975. Fortunately, put a US connector on the “free” end in every Russian Androgynous Moscow’s Rocket and Space of each cable that led to the docking Peripheral Docking System electronic Corporation Energia had further system. Each side could engineer component, beginning a new era in developed the joint US-Russian from there to its own standards and international cooperation. And this docking system originally created for hardware. Yet, even that simple plan happened just in time, as the US and the Apollo-Soyuz Test Project in had obstacles. Whose wire would partners were poised to begin work on a anticipation of their own shuttle—the be in the cable? project of international proportions. Buran. Thus, the needed mechanism was already installed on Mir. The Russians had a docking mechanism on their space station in a 51 .6-degree orbit, awaiting a shuttle. That View of the Orbiter mechanism had a joint US-Russian Docking System that allowed the shuttle design heritage. The Americans had a to attach to the fleet of shuttles that needed to practice International Space servicing missions to a space station Station. This close-up in a 51 .6-degree orbit. In a surprisingly image shows the rapid turn of events, the US shuttle’s payload bay closeout on STS-130 (2010). basic design began to include a sophisticated Russian mechanism. That mechanism would remain a part of most of the shuttle’s ensuing missions.

The Space Shuttle and Its Operations 133 Construction of The Mir and the late-era Salyut stations in-space construction techniques, power were built from such self-contained systems, large gyroscopes, and robotics. the International spacecraft linked together. Although What emerged out of the union of Space Station Begins these Soviet stations were big, they were the Freedom and the Mir-II programs somewhat like structures built primarily was a space station vastly larger and The International Space Station (ISS) out of the trucks that brought the pieces more robust (and more complicated) was a new kind of spacecraft that and were not of a monolithic design. than either side had envisioned. would have been impossible without Only about 15% of each module could the shuttle’s unique capabilities; it be dedicated to science. The rest of the mass was composed of the infrastructure The Pieces Begin to was the first spacecraft designed to be Come Together assembled in space from components needed to get the mass to the station. that could not sustain themselves The ISS would take the best features Although the ISS ultimately included independently. The original 1984 of both the merged Mir-II and the several necessary Mir-style modules International Freedom Space Station— Freedom programs. It would use in the Russian segment, the other already well along in its manufacture— proven Russian reliability in logistics, partner elements from the United States, was reconfigured to be the forward propulsion, and basic life support and Canada, European Space Agency, Italy, section of the ISS. The Freedom enormous new capabilities in US power, and Japan were all designed with the heritage was a crucial part of ISS plans, communications, life support, and shuttle in mind. Each of these several as its in-space construction was a thermal control. The integrated Russian dozen components was to be supported major goal of the program. All previous modules helped to nurture the first few by the shuttle until each could be spacecraft had either been launched structural elements of the US design supported by the ISS infrastructure. intact from the ground (such as the until the major US systems could be These major elements typically shuttle itself, Skylab, or the early carried to the station and activated. required power, thermal control, and Salyut space stations) or made of fully These major US systems were made telemetry support from the shuttle. functional modules, each launched possible by assembly techniques Not one of these chunks could make intact from the ground and hooked enabled by the shuttle. The United it to the ISS on its own, nor could any together in a cluster of otherwise States could curtail expensive and be automatically assembled into the independent spacecraft. difficult projects in both propulsion and ISS by itself. Thus, the shuttle enabled crew rescue vehicles and stop worrying a new era of unprecedented in situ construction capability. This timeline represents the Space Shuttle about the problem of bootstrapping fleet’s delivery and attachment of several their initial infrastructure, while the Because it grew with every mission, major components to the International Russians would be able to suspend the ISS presented new challenges to Space Station. The specific components sophisticated-but-expensive efforts in are outlined in red in each photo.

Endeavour (STS-88) brought US-built Unity Discovery (STS-92) delivered Z1 truss and Endeavour (STS-97) delivered new node, which attached to Russian-built Zarya. antenna (top) and one of the mating adapters. solar array panels.

1998 2000

134 The Space Shuttle and Its Operations spacecraft engineering in general and elements dramatically cooled at the tip of a remote manipulator. to the shuttle in particular. With each throughout the flight to the ISS. On The assembly tasks in orbit involved a new module, the spacecraft achieved previous space station generations like combination of docking, berthing, more mass, a new center of mass, new Skylab, Salyut, and Mir, such modules automatic capture, automatic antenna blockages, and some enhanced needed heaters, a control system to deployment, and good old-fashioned or new capability and constraints. regulate them, and a power supply to elbow grease. run them both. These functions all During the assembly missions, the The shuttle had mastered the rendezvous passed to the shuttle, allowing an shuttle and the ISS would each need and docking issues in a high-inclination optimized design of each ISS element. to reconfigure the guidance, navigation, orbit during the Mir Phase 1Program. and control software to account for Each mission, therefore, had a kind of However, just getting there and getting several different configurations. special countdown called the “Launch to docked would not assemble the ISS. Each configuration needed to be Activation” timeline. This unique Berthing and several other attachment analyzed for free flight, initial docked timeline for every cargo considered how techniques were required. configuration with the arriving long it would take before such element still in the Orbiter payload bay, temperature limits were reached. and final assembled and mated Sometimes, the shuttle’s ground support Docking and Berthing configuration with the element in its systems would heat the cargo in the Docking ISS position. There were usually one payload bay for hours before the launch or two intermediate configurations with to gain some precious time in orbit. Docking and berthing are conceptually the element robotically held at some Other times electric heaters were similar methods of connecting a distance between the cargo bay and its provided to the cargo element at the pressurized tunnel between two final destination. expense of shuttle power. At certain objects in space. The key differences times the shuttle would spend extra time arise from the dynamic nature of the Consequently, crews had to update pointing the payload bay intentionally docking process with potentially large a lot of software many times during toward the sun or the Earth during the residual motions. In addition, under the mission. At each step, both the long rendezvous with the ISS. All these docking there is a need to complete ISS and the shuttle experienced a new activities led to a detailed planning the rigid structural mating quickly. and previously unflown shape and process for every flight that involved Such constraints are not imposed on size of spacecraft. thermal systems, attitude control, the slower, robotically controlled Even the most passive cargos robotics, and power. berthing process. involved active participation from the The growth of the ISS did not come Docking spacecraft need to mate shuttle. For example, in the extremely at the push of a button or even solely quickly so that attitude control can be cold conditions in space, most cargo restored. Until the latches are secured,

Atlantis (STS-98) brought Destiny laboratory. Endeavour (STS-100) delivered and attached Atlantis (STS-104) delivered Quest airlock. Space Station Robotic Arm.

2001

The Space Shuttle and Its Operations 135 there is very little structural strength at the interface. Therefore, neither vehicle attempts to fire any thrusters or exert any control on “the stack.” During this period of free drift, there is no telling which attitude can be expected. The sun may consequently end up pointing someplace difficult, such as straight onto a radiator or edge-on to the arrays. Thus, it pays to get free-flying vehicles latched firmly together as quickly as possible. Due to the large thermal differences— up to 400° C (7 52°F) between sun-facing metal and deep-space-facing metal— Astronaut Peggy Whitson, Expedition 16 commander, works on Node 2 outfitting in the vestibule between the thermal expansion of large metal the Harmony node and Destiny laboratory of the International Space Station in November 2007. surfaces can quickly make the precise alignment of structural mating hooks or is somewhat akin to the moment when from the vehicle’s center of gravity. bolts problematic, unless the metal a large ship first tosses its shore lines Sufficient torque had to be applied at surfaces have substantial time to reach to dock hands on the pier; it serves the interface to overcome the large the same temperature. As noted, time is only to keep the two vehicles lightly moment of the massive shuttle as it of the essence. Hence, docking connected while the next series of damped its motion. mechanisms were forced to be small— functions is completed. about the size of a manhole—due to Next, the mechanism had to retract, this need to rapidly align in the The mechanism must next damp out pulling the two spacecraft close enough presence of large thermal differences. leftover motions in X, Y, and Z axes together that strong latches could as well as damp rotational motions engage. The strong latches clamped A docking interface is a sophisticated in pitch, yaw, and roll while bringing the two halves of the mechanism mechanism that must accomplish many the two spacecraft into exact together with enough force to compress difficult functions in rapid succession. alignment. This step was a particular the seals. These latches held the It must mechanically guide the challenge for shuttle dockings. For the halves together against the huge force approaching spacecraft from its first first time in space history, the docking of pressure that would try to push them contact into a position where a “soft mechanism was placed well away apart once the hatches were opened capture” can be engaged. Soft capture inside. While this final cinching of

Atlantis (STS-110) delivered S0 truss. Atlantis (STS-112) brought S1 truss. Endeavour (STS-113) delivered P1 truss.

2002

136 The Space Shuttle and Its Operations the latches happened, hundreds of simultaneously mated. All berthing electrical connections and even a interface utilities were subsequently few fluid transfer lines had to be hooked between the modules in the automatically and reliably connected. pressurized tunnel (i.e., in a Finally, there had to be a means to let “shirtsleeve” environment). During air into the space between the hatches, extravehicular activities (EVAs), and all the hardware that had been astronauts connected major cable routes filling the tunnel area had to be only where necessary. removed before crew and cargo could The interior cables and ducts connected freely transit between the spacecraft. in a vestibule area inside the sealing Berthing rings and around the hatchways. This arrangement allowed thousands Once docked, the shuttle and of wires and ducts to course through station cooperated in a gentler way the shirtsleeve environment where they called berthing, which led to much could be easily accessed and maintained larger passageways. while allowing the emergency closure The Unity connecting module is being put of any hatch in seconds. This hatch into position to be mated to Endeavour’s Berthing was done under the control (STS-88 [1998]) docking system in the cargo closure could be done without the need of a robotic arm. It was the preferred bay. This mating was the first link in a long chain to clear or cut cables that connected the method of assembling major modules of events that led to the eventual deployment modules. This “cut cable to survive” of the connected Unity and Zarya modules. of the ISS. The mechanism halves situation occurred, at great peril to the could be held close to each other crew, for several major power cables could only reach the length of the indefinitely to thermally equilibrate. across a docking assembly during the payload bay, the ISS needed a The control afforded by the robotic Mir Program. second-generation arm to position its positioning meant that the final assembly segments and modules for alignment and damping system in subsequent hooking, berthing, and/or berthing could be small, delicate, and Robotic Arms Provide EVA bolt-downs. lightweight while the overall tunnel Necessary Reach could be large. Building upon the lessons learned The assembly of the enormous ISS from the shuttle experience, the same In the case of the ISS, the berthing required that large structures were Canadian Space Agency and contractor action only completed the hard placed with high precision at great team created the larger, stiffer, and structural mating and sealing, unlike distance from the shuttle’s payload more nimble Space Station Robotic docking, where all utilities were bay. As the Shuttle Robotic Arm

Atlantis (STS-115) brought P3/P4 truss. Discovery (STS-116) delivered P5 truss. Atlantis (STS-117) delivered S3/S4 truss and another pair of solar arrays.

2006 2007

The Space Shuttle and Its Operations 137 Arm, also known as the “big arm.” The robotic feats were amazing between the segments. The crew then The agency and team created a 17-m indeed—and unbelievable at times— attached major appendages and (56-ft) arm with seven joints. The yet successful construction of the payloads with a smaller mechanism completely symmetric big arm was ISS depended on a collaboration of called a Common Attachment System. also equipped with the unique ability to human efforts, ingenuity, and a host Where appropriate, major systems were use its end effector as a new base of of other “nuts-and-bolts” mechanisms automatically deployed or retracted operations, walking end-over-end and techniques. from platforms that were pre-integrated around the ISS. Together with a mobile to the delivered segment before launch. transporter that could carry the new The solar array wings were deployed by arm with a multiton cargo element at Other Construction swinging two half-blanket boxes open its end, the ISS robotics system worked Mechanisms from a “folded hinge” launch position in synergy with the Shuttle Robotic The many EVA tests conducted by and then deploying a collapsible mast to Arm to maneuver all cargos to their shuttle crews in the 1980s inspired ISS extend and finally to stiffen the blankets. final destinations. designers to create several simplifying Like the Russian segment’s smaller The Space Station Robotic Arm could construction techniques for the solar arrays, the tennis-court-sized grip nearly every type of grapple enormous complex. While crews US thermal radiators deployed fixture that the shuttle’s system could assembled the pressurized modules automatically with an extending handle, which enabled the astounding using the Common Berthing scissor-like mechanism. combined robotic effort to repair a Mechanism, they had to assemble major Meanwhile, the ISS design had to torn outboard solar array on STS -1 20 external structures using a simple large- accommodate the shuttle. It needed to (2007). On that memorable mission, hook system called the Segment-to- provide a zigzag tunnel mechanism the Space Station Robotic Arm Segment Attachment System designed (the Pressurized Mating Adapter) to “borrowed” the long Orbiter Boom for high strength and rapid alignment. optimize the clearance to remove Sensor System, allowing an The Segment-to-Segment Attachment payloads from the bay after the shuttle unprecedented stretch of 50 m (1 65 ft) System had many weight and had docked. ISS needed to withstand down the truss and 27 m (90 ft) up to reliability enhancements resulting from the shuttle’s thruster plumes for heating, reach the damage. the lack of a need for a pressurized loads, contamination, and erosion. It The Space Station Robotic Arm was seal. Such over-center hooks were also had to provide the proper electrical robust. Analysis showed that it was used in many places on the ISS exterior. grounding path for shuttle electronics, capable of maneuvering a fully loaded In major structural attachments even though the ISS operated at a Orbiter to inspect its underside from (especially between segments of the significantly higher voltage. the ISS windows. 100-m [328-ft] truss), the EVA crew additionally drove mechanical bolts

Endeavour (STS-118) delivered the Discovery (STS-120) brought Harmony Atlantis (STS-122) delivered European Space S5 truss segment. Node 2 module. Agency’s Columbus laboratory.

2007 2008

138 The Space Shuttle and Its Operations Improvements to the Shuttle Facilitated Assembly of the International Space Station

NASA had to improve Space Shuttle ISS, the launch window was limited to a capability before the International Space period of about 5 minutes, when the launch Station (ISS) could be assembled. The pad on the rotating Earth was aligned altitude and inclination of the ISS orbit with the ISS orbit. By rearranging the required greater lift capability by the prelaunch checklist to complete final tests shuttle, and NASA made a concerted effort earlier and by adding planned hold periods to reduce the weight of the vehicle. to resolve last-minute technical concerns, Engineers redesigned items such as crew the 5-minute launch window could be met seats, storage racks, and thermal tiles. with high reliability. The super lightweight External Tank Finally, physical interfaces between the Astronaut Carl Walz, Expedition 4 flight allowed the larger ISS segments to be engineer, stows a small transfer bag into a shuttle and the ISS needed to be launched and assembled. Modifications larger cargo transfer bag while working in the coordinated. NASA designed docking International Space Station Unity Node 1 during to the ascent flight path and the firing of fixtures and transfer bags to joint docked operations with STS-111 (2002). Orbital Maneuvering System engines accommodate the ISS. The agency alongside the main engines during ascent modified the rendezvous sequence to ISS to the shuttle. This allowed the shuttle provided a more efficient use of propellant. prevent contamination of the ISS by to remain docked to the ISS for longer Launch reliability was another concern. the shuttle thrusters. In addition, NASA periods, thus maximizing the work that For the shuttle to rendezvous with the could transfer electrical power from the could be accomplished.

Further Improvements of miles by the shuttle’s star tracker so seeking vastly dimmer points of light. Facilitate Collaboration that rendezvous could be conducted. Thus, the shuttle’s final rendezvous Between Shuttle and Station The ISS was so huge that in sunlight it with the ISS involved taking a relative would saturate the star trackers of the navigational “fix” on the ISS at night, The ISS needed a tiny light source that shuttle, which were accustomed to when the ISS’s small light bulb could be seen at a distance of hundreds approximated the light from a star.

Endeavour (STS-123) brought Kibo Japanese Endeavour (STS-123) also delivered Canadian- Discovery (STS-124) brought Pressurized Experiment Module. built Special Purpose Dextrous Manipulator. Module and robotic arm of Kibo Japanese Experiment Module.

2008 continued

The Space Shuttle and Its Operations 139 Other navigational aids were mounted This choreography grew progressively The Roles of on the ISS as well. These aids included a more worrisome as the ISS added visual docking target that looked like a more arrays. It was particularly the Space Shuttle branding iron of the letter “X” erected difficult during the last stages of Program Throughout vertically from a background plate in the docking and in the first moments of center of the hatch. Corner-cube glass a shuttle’s departure, when it was Construction reflectors were provided to catch a laser necessary to fire thrusters in the general Logistics Support— beam from the shuttle and redirect it direction of the station. Expendable Supplies straight back to the shuttle. This There were also limits as to how soon remarkable optical trick is used by The shuttle was a workhorse that a shuttle might be allowed to fire an several alignment systems, including the brought vast quantities of hardware engine after it had just fired one. European Space Agency’s rendezvous and supplies to the International Space It was possible that the time between system that targeted other places on the Station (ISS). Consumables and spare each attitude correction pulse could ISS. Thus, it was necessary to carefully parts were a key part of that manifest, match the natural structural frequency shield the different space partners’ with whole shuttle missions dedicated of that configuration of the ISS. This reflectors from the beams of each to resupply. These missions were called pulsing could amplify oscillations to other’s spacecraft during their respective “Utilization and Logistics Flights.” the point where the ISS might break if final approaches to the ISS. Otherwise All missions—even the assembly protection systems were not in place. a spacecraft might “lock on” to the flights—contributed to the return of Of course, this frequency changed each wrong place for its final approach. trash, experiment samples, completed time the ISS configuration changed. experiment apparatus, and other items. As the station grew, it presented new Thus, the shuttle was always loading challenges to the shuttle’s decades-old new “dead bands” in its control logic to control methods. The enormous solar prevent it from accidentally exciting Unique Capacity to arrays, larger than America’s Cup yacht one of these large station modes. Return Hardware and sails, caught the supersonic exhaust In all, the performances of all the Scientific Samples from the shuttle’s attitude control jets “players” in this unfolding drama were and threatened to either tear or Perhaps the greatest shuttle contribution stellar. The complexity of challenges accelerate the station in some strange to ISS logistics was its unsurpassed required flexibility and tenacity. angular motion. Thus, when the shuttle capability to return key systems and The shuttle not only played the lead was in the vicinity of or docked to the components to Earth. Although most of in the process, it also served in ISS, a careful ballet of shuttle engine the ISS worked perfectly from the start, supporting roles throughout the entire selection and ISS array positions was the shuttle’s ability to bring components construction process. always necessary to keep the arrays and systems back was essential in from being damaged. rapidly advancing NASA’s engineering

Discovery (STS-119) brought Endeavour (STS-127) delivered Kibo Japanese Endeavour (STS-130) delivered Node 3 S6 truss segment. Experiment Module Exposed Facility and with Cupola. Experiment Logistics Module Exposed Section. 2009 2010

140 The Space Shuttle and Its Operations knowledge in many key areas. This allowed ground engineers to thoroughly Mass Transported by Space Shuttle to Station diagnose, repair, and sometimes (kg) 20,000 redesign the very heart of the ISS. (pounds) 44,000 19,100 The shuttle upmass was a highly 42,000 18,100 valued financial commodity within 40,000 17,200 the ISS Program, but its recoverable d 38,000 a o l 16,300 down-mass capability was unique, y a 36,000 P hotly pursued, and the crown jewel 15,400 34,000 at the negotiation table. As it became 14,500 clear that more and more partners 32,000 13,600 5 4 3 2 1 0 9 8 7 6 9 4 3 2 0 8 7 6 5 1 4 3 2 1 0 8 5 4 0 2 6 2 7 8 1 would have the capability to deliver 30,000 8 6 3 3 3 3 3 3 2 2 2 2 1 2 2 2 2 1 1 1 1 2 1 1 1 1 1 0 0 0 0 0 0 9 9 9 0 8 9 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 cargo to the ISS but only NASA STS Mission retained any significant ability to return cargo intact to Earth, the cachet cargo to ride up with the shuttle on assembly—much of it “hands on”— only increased. Even the Russian every launch in place of such canisters. in the harsh environment of space. partner—with its own robust resupply The shuttle would even carry precious Spacewalking crews assembled the capabilities and long, proud history ice cream and frozen treats for the ISS ISS in well over 100 extravehicular in human spaceflight—was seduced crews in freezers needed for the return activity (EVA) sessions, usually lasting by the lure of recoverable down mass of frozen medical samples. 5 hours or more. EVA is tiring, time and agreed that its value was twice consuming, and more dangerous than that of 1 kg (2.2 pounds) of upmass. The shuttle would periodically reboost routine cabin flight. It is also NASA negotiators had a particular the ISS, as needed, using any leftover exhilarating to all involved. Despite fondness for this one capability that propellant that had not been required for the dangers of EVA, the main role for the Russians seemed to value higher contingencies. The shuttle introduced air shuttle in the last decade of flight was than their own capabilities. into the cabin and transferred to assemble the ISS. Therefore, EVAs compressed oxygen and nitrogen to the came to dominate the shuttle’s activities ISS tanks as its unused reserves allowed. during most station visits. Symbiotic Relationship ISS crews even encouraged shuttle Between Shuttle and the crews to use their toilet so that the These shuttle crew members were International Space Station precious water could be later recaptured trained extensively for their respective from the wastes for oxygen generation. missions. NASA scripted the shuttle Over time the two programs developed flights to achieve ambitious assembly several symbiotic logistic relationships. The ISS kept stockpiles of food, water, objectives, sometimes requiring four The ISS was eager to take the and essential consumables that were EVAs in rapid succession. The level of pure-water by-product of the shuttle’s collectively sufficient to keep a guest proficiency required for such long, fuel cell power generators because crew of seven aboard for an additional complicated tasks was not in keeping water is the heaviest and most vital 30 days—long enough for a rescue with the ISS training template. consumable of the life support system. shuttle to be prepared and launched to Therefore, the shuttle crews handled The invention of the Station to Shuttle the ISS in the event a shuttle already at most of the burden. They trained until Power Transfer System allowed the the station could not safely reenter the mere days before launch for the shuttle to draw power from the ISS Earth’s atmosphere. marathon sessions that began shortly solar arrays, thereby conserving its own after docking. oxygen and hydrogen supplies and extending its stay in orbit. Extravehicular Activity by Space Shuttle Crews Shuttle Airlock The ISS maintained the shared Between assembly flights STS-97 contingency supply of lithium hydroxide Even with all of the automated and (2000) and STS -1 04 (20 01 )—the first canisters for carbon dioxide scrubbing robotic assembly, a large and complex time a crew was already aboard the ISS by both programs, allowing more vehicle such as the ISS requires an enormous amount of manual to host a shuttle and the flight when

The Space Shuttle and Its Operations 141 Clayton Anderson Astronaut on STS-117 (2007) and STS-131 (2010). Spent 152 days on the International Space Station before returning on STS-120 (2007).

“Life was good on board the International Space Station (ISS). Time typically passed quickly, with much to do each day. This was especially true when an ISS crew prepared to welcome ‘interplanetary guests’…or more specifically, a Space Shuttle crew! During my 5-month ISS expedition, our Astronaut Clayton Anderson, Expedition 15 flight engineer, smiles ‘visitors from another planet’ included STS-117 (my ride up), for a photo while floating in the Unity node of the International Space Station. STS-118, and STS-120 (my ride down). “The integration of shuttle and ISS crews was like forming “While awaiting a shuttle’s arrival, ISS crews prepared in an ‘All-Star’ baseball team. In this combined form, wonderful many ways. We may have said goodbye to ‘trash-collecting things happened. At the moment hatches swung open, tugs’ or welcomed replacement ships (Russian Progress, a complicated, zero-gravity dance began in earnest and a European Space Agency Automated Transfer Vehicle, and the well-oiled machine emerged from the talents of all on board Japanese Aerospace Exploration Agency H-II Transfer Vehicle) executing mission priorities flawlessly! fully stocked with supplies. Just as depicted in the movies, life on the ISS became a little bit like Grand Central Station! “Shuttle departure was a significant event. I missed my STS-117 and STS-118 colleagues as soon as they left! “Prepping for a shuttle crew was not trivial. It was I wanted them to stay there with me, flying through the reminiscent of work you might do when guests are coming station, moving cargo to and fro, knocking stuff from the to your home! ISS crews ‘pre-packed…,’ gathering loads walls! The docked time was grand…we accomplished so of equipment and supplies no longer needed that must be much. To build onto the ISS, fly the robotic arm, perform disposed of or may be returned to Earth…like cleaning spacewalks, and transfer huge amounts of cargo and supplies, house! This wasn’t just ‘trash disposal’—sending a vehicle we had to work together, all while having a wonderfully good to its final rendezvous with the fiery friction of Earth’s time. We talked, we laughed, we worked, we played, and we atmosphere. Equipment could be returned on shuttle to thoroughly enjoyed each other’s company. That is what enable refurbishment for later use or analyzed by experts camaraderie and ‘crew’ was all about. I truly hated to see to figure out how it performed in the harsh environment of them go. But then they were home…safe and sound with outer space. It was also paramount to help shuttle crews by their feet firmly on the ground. For that, I was always grateful, prepping their spacewalking suits and arranging the special yet I must admit that when a crew departed I began to tools and equipment that they would need. This allowed think more of the things that I did not have in orbit, some them to ‘jump right in’ and start their work immediately 354 km (220 miles) above the ground. after crawling through the ISS hatch! Shuttle flights were all about cramming much work into a short timeframe! “Life was good on board the ISS…I cherished every single The station crew did their part to help them get there! minute of my time in that fantastic place.”

142 The Space Shuttle and Its Operations the ISS Quest airlock was activated, of ISS EVAs and shuttles provided the was abandoned in later flights. respectively—the shuttle crews were majority of the gases for this work. Launch and re-entry suits needed to be hampered by a short-term geometry Docked shuttles could replenish the shared or, worse, spared on the Orbiter problem. The shuttle’s airlock was part small volume of unrecoverable air that middeck to fit the arriving and departing of the docking tunnel that held the two could not be compressed from the crew member. Different Russian suits spacecraft together, so in that period the airlock. The prebreathe procedure of were used in the Soyuz rescue craft, so shuttle crew had to be on its side of pure oxygen to the EVA crew also was those suits had to make the manifest the hatch during all such EVAs in case supported by shuttle reserves through a somewhere. Further, a special custom-fit of an emergency departure. Further, system called Recharge Oxygen Orifice seat liner was necessary to allow each the preparations for EVA required that Bypass Assembly. This system was crew member to safely ride the Soyuz the crew spend many hours at reduced delivered on STS -11 4 (2005) and used to an emergency landing. This seat liner pressure, which was accomplished for the first time on STS -12 1 (2006). had to be ferried to the ISS with each prior to Quest by dropping the entire Finally, the shuttle routinely new crew member who might use the shuttle cabin pressure. Since the ISS repressurized the ISS high-pressure Soyuz as a lifeboat. Thus, a lot of was designed to operate at sea-level oxygen and nitrogen tanks and/or the duplication occurred in the hardware atmosphere, it was necessary to keep cabin itself prior to leaving. The ISS required for shuttle-delivered crews. the shuttle and station separated by rarely saw net losses in its on-board closed hatches while EVAs were in supplies, even in the midst of such Shuttle Launch Delays preparation or process. This hampered intense operations. Fewer ISS As a shuttle experienced periodic the transfer of internal cargos and other consumables were thus used whenever delays of weeks or even months from intravehicular activities. a shuttle could support the EVAs. its original flight plan, it was necessary International Space Station Airlock to replan the activities of ISS crews The Shuttle as Crew Transport who were expecting a different crew On assembly flight 7A (STS -1 04), the makeup. Down-going crews sometimes addition of the joint airlock Quest Although many crews came and went found their “tours of duty” had allowed shuttle crews to work in aboard the Russian Soyuz rescue craft, been extended. Arriving crews found continuous intravehicular conditions the shuttle assisted the ISS crew their tours of duty shortened and their while their EVA members worked rotations at the station during early work schedule compressed. As the outside. Even in this airlock, shuttle flights. This shuttle-based rotation of construction evolved, the shuttle carried crews continued to conduct the majority ISS crew had several significant a smaller fraction of the ISS crew. drawbacks, however, and the practice

Left photo: Astronauts John Olivas (top) and Christer Fuglesang pose for a photo in the STS-128 (2009) Space Shuttle airlock. Right photo: Astronauts Garrett Reisman (left) and Michael Good—STS-132 (2010)—pose for a photo between two extravehicular mobility units in the International Space Station (ISS) Quest airlock. By comparison, the Quest airlock is much larger and thus allows enough space for the prebreathe needed to prevent decompression sickness to occur in the airlock, isolated from the ISS.

The Space Shuttle and Its Operations 143 of exercise equipment and then refurbishing it; not the sort of thing they could just dive in and do without Michael Foale, PhD reviewing the procedures. Astronaut on STS-45 (1992), STS-56 (1993), STS-63 (1995), STS-84 (1997), and Shuttle Helps Build STS-103 (1999). International Partnerships Spent 145 days on Russian space station Mir before returning on STS-86 (1997). Partnering With the Russians Spent 194 days as commander of Expedition 8 It is hard to overstate the homogenizing on the International Space but draconian effect that the shuttle On board the International Space Station, Astronaut Michael Station (2003-2004). initially had on all the original Foale fills a water microbiology bag for in-flight analysis. international partners who had joined the Freedom Space Station Program or “When we look back 50 years to this time, we won't remember the experiments who took part in other cooperative that were performed, we won't remember the assembly that was done. spaceflights and payloads. The shuttle What we will know was that countries came together to do the first joint was the only planned way to get their international project, and we will know that that was the seed that started us hardware and astronauts to orbit. Thus, “international integration” was off to the moon and Mars.” decidedly one-sided as NASA engineers and operators worked with existing partners to meet shuttle standards.

Whenever NASA scrubbed a launch says that they can dock. Two days Such standards included detailed attempt for even 1 day, the scrub before they are to get here, they tell us specifications for launch loads disrupted the near-term plan on board that they’re not coming on that day. capability, electrical grounding and the ISS. Imagine the shuttle point of For the next week or so of attempts, power quality, radio wave emission view in such a scrub scenario: “We’ll they will be able to tell us only at the and susceptibility limits, materials try again tomorrow and still run exactly moment of launch that they will in fact outgassing limits, flammability limits, the script we know.” be arriving 2 days later.” toxicity, mold resistance, surface temperature limits, and tens of Now imagine the ISS point of view in At that juncture, did ISS crew members thousands of other shuttle standards. the same scenario: “We’ve been sleep shift? Did they shut down the The Japanese H-II Transfer Vehicle planning to take 12 days off from our payloads and rewire for the shuttle’s and European Space Agency’s (ESA’s) routine to host seven visitors at our arrival? Did they try to cram in one Automated Transfer Vehicle were home. These visitors are coming to more day of experiments while they not expected until nearly a decade rehab our place with a major new waited? Did they pack anything at all? after shuttle began assembly of the home addition. We need to wrap up This was the type of dilemma that ISS. Neither could carry crews, so all any routine life we’ve established and crews and planners faced leading astronauts, cargoes, supplies, and conclude our special projects and up to every launch. Therefore, a few structures had to play by shuttle’s rules. then rearrange our storage to let these weeks before each launch, ISS seven folks move back and forth, start planners polled the technical teams Then the Earth Moved packing things for the visitors to take for the tasks that could be put on the with them, and reconfigure our wiring “slip schedule,” such as small tasks The Russians and Americans started and plumbing to be ready for them to or day-long procedures that could working together with a series of do their work. Then we must sleep be slotted into the plan on very short shuttle visits to the Russian space shift to be ready for them at the strange notice. Some of these tasks were station Mir. There was more at stake hour of the day that orbital mechanics complex, like tearing down a piece than technical standards. Leadership

144 The Space Shuttle and Its Operations roles were more equitably distributed path. It also provided the Russian have to retest its hardware to a new and cooperation took on a new government a huge boost in prestige as standard. During the Mir Phase 1 diplomatic flavor in a true partnership. a senior partner in the new worldwide Program, the shuttle encountered the partnership. That critical role made new realities of cooperative spaceflight In the era following the fall of the Russian integration the dominant and set about the task of defining new Berlin Wall (1 989) along with the end focus of shuttle integration, and it ways of doing business. of Soviet communism and the Soviet subsequently changed the entire US Union itself, the US government seized It was difficult but necessary to perspective on international spaceflight. the possibility of achieving two key compare every standard for mutual goals—the seeding of a healthy Two existing spacecraft were about to acceptability. In most cases, the intent of economy in Russia through valuable meet, and engineers in each country had the constraint was instantly compatible western contracts, and the prevention to satisfy each other that it was and the implementation was close of the spread of the large and safe for each vehicle to do so. Neither enough to sidestep an argument. The now-saleable missile and weapon side could be compelled to simply standards compatibility team worked technology to unstable governments accept the other’s entire system of tirelessly for 4 years to allow cross from the expansive former Soviet standards and practices. The two sides certification. This was an entirely new military-industrial complex that was certainly could not retool their experience for the Americans. particularly cash-strapped. The creation programs, even if they had wanted to As difficult as the technical of a joint ISS was a huge step toward accept new standards. Tens of thousands requirements were, an even more each of those goals, while providing of agreements and compromises had to fundamental issue existed in the the former Freedom program with an be reached, and quickly. Only where documents themselves. The Russians additional logistics and crew transport absolutely necessary did either side had never published in English and, similarly, the United States had not published in Cyrillic, the alphabet of Financial Benefits of the Space Shuttle the Russian language. Chaos might immediately ensue in the computers for the United States that tracked each program’s data.

Just as the International Space Station (ISS) international agreements called for each Communicating With Multiple Alphabets partner to meet its obligations to share in common operations costs such as propellant The space programs needed something delivery and reboost, the agreements also required each partner to bear the cost of robust to handle multiple alphabets, delivering its contributions and payloads to orbit and encouraged use of barter. As a and they needed it soon. In other words, result, the European Space Agency (ESA) and the Japan Aerospace Exploration Agency the programs needed more bytes for (JAXA) took on the obligation to build some of the modules within NASA’s contribution every character. Thus, the programs as payment in kind for the launch of their laboratories. In shifting the cost of became early adopters of the system that several Asian nations had been development and spares for these modules to the international partners—and without forced to adopt as a national standard taking on any additional financial obligation for the launch of the partner labs—NASA to capture the 6,000+ characters of was able to provide much-needed fiscal relief to its capped “build-to-cost” kanji—pictograms of Chinese origin development budget in the post-redesign years. The Columbus laboratory took a used in modern Japanese writing. dedicated shuttle flight to launch. In return, ESA built Nodes 2 and 3 and some The Universal Multiple-Octet Coded research equipment. The Japanese Experiment Module that included Kibo would take Character Set—known in one 2.3 shuttle flights to place in orbit. JAXA paid this bill by building the Centrifuge ubiquitous word processing Accommodation Module (later deleted from the program by NASA after the Vision for environment as “Unicode” and standardized worldwide as International Space Exploration refocused research priorities on the ISS) and by providing other Standards Organization (ISO) Standard payload equipment and a non-ISS launch. 10646—allowed all character sets of

The Space Shuttle and Its Operations 145 the world to be represented in all their suits in tribute to their fallen Russian end of the station, whereas desired fonts. Computers in space comrades. After the Columbia accident, the Japanese elected to berth their agencies around the world quickly the Russians launched 14 straight vehicle—the H-II Transfer Vehicle— modified to accept the new character uncrewed and crewed missions to to the station. The manipulation of ISO Standard, and instantly the cosmos continue the world’s uninterrupted the H-II Transfer Vehicle and its was accessible to the languages of all human presence in space before the berthing to the ISS were similar to nations. This also allowed a common shuttle returned to share in those duties. the experience of all previous modules lexicon for acronyms. that the shuttle had brought to the space Other Faces on station. The big change was that the National Perceptions the International Stage vehicle had to be grabbed in free flight by the station arm—a trick previously The Russians had a highly “industrial” All the while, teams of specialists from only performed by the much more approach to operating a spacecraft. the Canadian Space Agency, Japanese nimble shuttle arm. NASA ISS Their cultural view of a space station Space Exploration Agency, Italian engineers and Japanese specialists appeared to most Americans to be Space Agency, and ESA each worked worked for years with shuttle robotics more as a facility for science, not side-by-side with NASA shuttle and veterans to develop this exotic necessarily a scientific wonder unto station specialists at Kennedy Space procedure for the far-more-sluggish ISS. itself. Although the crews continued Center to prepare their modules for to be revered as Russian national launch aboard the shuttle. Shortly after The experience paid off. In the grapple heroes, the spacecraft on which they the delivery of the ESA Columbus of H-II Transfer Vehicle 1 in 2009, flew never achieved the kind of iconic laboratory on STS -1 22 (2008) and the and following the techniques first status that the Space Shuttle or the Japanese Kibo laboratory on STS -1 24 pioneered by shuttle, the free-flight ISS achieved in the United States. (2008), each agency’s newly developed grapple and berth emerged as the By contrast, the American public was visiting cargo vehicle joined the fleet. attachment technique for the upcoming more likely to know the name of the fleet of commercial space transports The Europeans had elected to dock particular one of four Orbiters flying expected at the ISS. their Automated Transfer Vehicle at the the current mission than the names of the crew members aboard. Although the Soyuz was reliable, it was “For Shuttle ESA was a junior partner, but now a small capsule—so small that it limited the size of crews that could use it as a with ISS we are equal partners” —Volker Damann, ESA lifeboat. All crew members required long stays in Russia to train for Soyuz and many Russian life-critical systems. This was in addition to their US training and short training stays with the other partners. Overall, however, the benefits of having this alternate crew and supply launch capability were Canadian Space Agency European Space Agency Japan Aerospace Exploration Agency abundantly clear in the wake of the Columbia (STS -1 07) accident in 2003. The Russians launched a Progress supply ship to the ISS within 24 hours and then launched an international crew of Ed Lu and Yuri Malenchenko exactly

10 weeks after the accident. Both crew National Aeronautics and members wore the STS -1 07 patch on Space Administration Russian Federal Space Agency

146 The Space Shuttle and Its Operations From Shuttle-Mir to International Unheeded Skylab Lesson: Take a Break! Space Station— The US planners might be applauded for their optimism and ambition in scheduling Crews Face Additional large workloads for the crew, but they had missed the lesson of a previous generation Challenges of planners resulting from the “Skylab Rebellion.” This rebellion occurred when the Skylab-4 crew members suddenly took a day off in response to persistent over-tasking The Shock of Long-Duration by the ground planners during their 83-day mission. From “Challenges of Space Spaceflights Exploration” by Marsha Freeman: NASA had very little experience with the realities of long-term flight. Since “At the end of their sixth week aboard Skylab, the third crew went on the shuttle’s inception, the shuttle team strike. Commander Carr, science pilot Edward Gibson, and Pogue stopped had been accustomed to planning working, and spent the day doing what they wanted to do. As have almost single-purpose missions with tight all astronauts before and after them, they took the most pleasure and scripts and well-identified manifests. The shuttle went through time-critical relaxation from looking out the windows at the Earth, taking a lot of stages of ascent and re-entry into Earth’s photographs. Gibson monitored the changing activity of the Sun, which had atmosphere on every flight, with limited also been a favourite pastime of the crew.” life-support resources aboard. Thus, the overall shuttle culture was that every It is both ironic and instructive to note that during the so-called “rebellion,” the crew second was crucial and every step was members actually filled their day off with intellectually stimulating activities that were potentially catastrophic. It took a while also of scientific use. Although these activities of choice were not the ones originally for NASA to become comfortable with the concept of “time to criticality,” scripted, they were a form of mental relaxation for these exhausted but dedicated where systems aboard a large station did scientists. The crew members of Skylab-4 just needed some time to call their own. not necessarily have to have immediate consequences. These systems often didn’t even have immediate failure was handled in stride and with great the shuttle’s heritage was one of recovery requirements. flexibility. Their flexible manifesting well-defined cargos with launch dates For instance, the carbon dioxide practices were a shock to veteran that were weather-dependent. scrubber or the oxygen generator could shuttle planners. The Soyuz and the Prior to the Mir experience, the shuttle be off for quite some time before the uncrewed Progress were particularly engineers had maintained stringent vast station atmosphere had to be reliable at getting off the pad on time, manifesting deadlines to keep the adjusted. What mattered most was come rain, sleet, wind, or clouds. This weight and balance of the Orbiter flexibility in the manifest to get needed reliability came from the Russians’ within tight constraints and to handle parts up to space. The shuttle’s self- simple capsule-on-a-missile heritage, the complex task of verifying the contained missions with well-defined and allowed mission planners to structural loads during ascent for the manifests were not the best experience pinpoint spacecraft arrivals and unique mix of items bolted to structures base for this pipeline of supplies. departures months in advance. The that would press against their fittings in cargos aboard the Progress, however, the payload bay in nonlinear ways. New Realities were tweaked up until the final day as Nonlinearity was a difficult side effect dictated by the needs at the destination, Russia patiently guided shuttle and then of the way that heavy loads had to be just as overnight packages are International Space Station (ISS) teams distributed. The load that each part of identified and manifested until the through these new realities. The the structure would see was completely final minutes aboard a regularly delivery of parts, while always urgent, dependent on the history of the loads it scheduled airline flight. In contrast,

The Space Shuttle and Its Operations 147 had seen recently. If a load was moved, capability to conduct operations for realize that most ISS expedition removed, or added to any of the cargo, extended hours, sleep shift as members expect to remain about 185 it could invalidate the analysis. necessary, and develop proficiency days in orbit. This experience, per crew in tightly scripted procedures. It was member, is equal to the combined Earth This was an acceptable way of like asking performers to polish a orbital, lunar orbital, and trans-lunar operating a stand-alone mission until 15-day performance, with up to 2 years experience accumulated by all US one faced a manifesting crisis such as of training to perfect the show. astronauts until the moment the United the loss of an oxygen generator or a Astronauts spent about 45 days of States headed to the moon on Apollo 11 . critical computer on the space station. training for each day on orbit. They Thus, each such Mir (or ISS) crew Shortly after starting the Mir Phase I would have time to rest before and after member matched the accumulated total Program, the pressures of emergency the mission, with short breaks, if any, crew experience of the first 9 years of manifest demands led to a new included in their timeline. the US space effort. suite of tools and capabilities for That would be a lot of training for a With initially three and eventually six the shuttle team. Engineers developed half-year ISS expedition. The crew long-duration astronauts permanently new computer codes and modeling would have to train for over 22 years aboard the ISS, the US experience in techniques to rapidly reconfigure under that model. One way to put the space grew at a rapidly expanding rate. the models of where the masses training issue into perspective is to By the middle of ISS Expedition 5 were attached and to show how the shuttle would respond as it shook during launch. Items as heavy as 250 kg (5 51 pounds) were swapped out in the cargo within months or weeks of launch. In some cases, items as large as suitcases were swapped out within hours of launch. During the ISS Program, Space Transportation System (STS) -1 24 carried critical toilet repair parts that had been hand-couriered from Russia during the 3-day countdown. The parts had to go in about the right place and weigh about the same amount as parts removed from the manifest for the safety analysis to be valid. Nevertheless, on fewer than 72 hours’ notice, the parts made it from Moscow to space aboard the shuttle.

Training The continuous nature of space station operations led to significant philosophical changes in NASA’s Posing in Node 2 during STS-127 (2009)/Expedition 20 Joint Operations: Front row (left to right) : training and operations. A major facet Expedition 20 Flight Engineer Robert Thirsk (Canadian Space Agency); STS-127 Commander Mark of the training adjustment had to do Polansky; Expedition 19/20 Commander Gennady Padalka (Cosmonaut); and STS-127 Mission with the emotional nature of Specialist David Wolf. Second row (left to right) : Astronaut Koichi Wakata (Japanese Aerospace long-duration activities. Short-duration Exploration Agency); Expedition 19/20 Flight Engineer Michael Barratt; STS-127 Mission Specialist Julie Payette (Canadian Space Agency); STS-127 Pilot Douglas Hurley; and STS-127 Mission Specialist shuttle missions could draw on Thomas Marshburn. Back row (left to right) : Expedition 20/21 Flight Engineer Roman Romanenko the astronauts’ emotional “surge” (Cosmonaut); STS-127 Mission Specialist Christopher Cassidy; Expedition 20 Flight Engineer Timothy Kopra; and Expedition 20 Flight Engineer Frank De Winne (European Space Agency).

148 The Space Shuttle and Its Operations (2002), only 2½ years into the ISS minimum of 8 hours per night for to provide specialized training on occupation, the ISS expedition crews long-term health. The Russians had demand. These were played on on-board had worked in orbit longer than warned eager US mission planners that notebook computers for the station crews had worked aboard all other their expectations of 10 hours of crew but occasionally for the shuttle US-operated space missions in the productive work from every crew crews as well. This training was useful previous 42 years, including the member every day, 6 days per week in executing large tasks on the slip shuttle’s 100+ flights. Clearly, the was unrealistic. A 5-day workweek schedule, unscheduled maintenance, or training model had to change. with 8-hour days (with breaks), plus on contingency EVAs scheduled well periodic holidays, was more like it. after the crew arrival on station. Shuttle operations were like a decathlon of back-to-back sporting Station crews worked on generic events—all intense, all difficult, and Different Attitude and Planning EVA skills, component replacement all in a short period of time—while of Timelines techniques, maintenance tasks, and space station operations were more general robotic manipulation skills. like an ongoing trek of many months, The ISS plan eventually settled in Many systems-maintenance skills requiring a different kind of stamina. exactly as the veteran Russian planners needed to be mastered for such a ISS used the “surge” of specialized had recommended. That is not to say huge “built environment.” The station training by the shuttle crews to execute that ISS astronauts took all the time systems needed to closely replicate most of the specialized extravehicular made available to them for purely a natural existence on Earth, including activities (EVAs) to assemble the personal downtime. These are some of air and water revitalization, waste vehicle. The station crew training the galaxy’s most motivated people, so management, thermal and power schedule focused on the necessary several “unofficial” ways evolved to let control, exercise, communications critical-but-general skills to deal them contribute to the program beyond and computers, and general cleaning with general trekking as well as the scripted activities, but only on a and organizing. a few planned specific tasks for that voluntary basis. The 363-metric-ton (400-ton) ISS expedition. Only rarely did ISS crews The ISS planners ultimately learned had a lot of hardware in need of routine take on major assembly tasks in the one productivity technique from the inspection and maintenance that, in period between shuttle visits (known Russians and the crews invented shuttle experience, was the job of in the ISS Program as “the stage”). another. At the Russians’ suggestion, ground technicians—not astronauts. Another key in the mission scripting the ground added a “job jar” of tasks These systems were the core focus of and training problem was to consider with no particular deadline. These tasks ISS training. There were multiple when and how that “surge capability” could occupy the crew’s idle hours. languages and cultures to consider could be requested of the ISS crew. If a job-jar item had grown too stale (most crew members were multilingual) That all depended on how long that and needed doing soon, it found its way and usually two types of everything: crew would be expected to work at the onto the short-term plan. Otherwise, two oxygen generators; two condensate increased pace, and how much rest the the job jar (in reality, a computer file collectors; two carbon dioxide crew members had had before that of good “things to do”) was a useful separators; multiple water systems; period. Nobody can keep competing in means to keep the crew busy during different computer architectures; and decathlons day after day; however, such off-duty time. The crew was inventive, even different food rations. Each ISS periodic surges were needed and would even adding new education programs crew member then trained extensively need to be compensated by periodic to such times. for the specific payloads that would be holidays and recovery days. active during his or her stay on orbit. Tasks vs. Skills Scores of payloads needed operators Humans need a balanced workday with and human subjects. Thus, it took about padding in the schedule to freshen up Generally, training for both the ground 3 years to prepare an astronaut for after sleep, read the morning news, eat, and the crew was skills oriented for long-duration flight. exercise, sit back with a good movie, station operations and task oriented for write letters, create, and generally shuttle operations. The trainers grew relax before sleep, which should be a to rely on electronic file transfers of intricate procedures, especially videos,

The Space Shuttle and Its Operations 149 Major Missions of robotic capture of the FGB from the called it “…the most difficult mission shuttle’s cargo element, Space Shuttle the shuttle has ever had to fly, and the Shuttle Support Endeavour needed to extend its arm simplest of all the missions it will have nearly to its limit just to reach the to do in assembling the ISS.” He was By May 2 01 0, the shuttle had flown free-flying FGB. Even so, the arm correct. The shuttle began an ambitious 34 missions to the International Space could only touch Zarya’s forward end. series of firsts, expanding its capabilities Station (ISS). Although no human with nearly every assembly mission. In the shuttle’s first assembly act of space mission can be called “routine,” the ISS Program, Astronaut Nancy some missions demonstrated STS-97—First US Solar Arrays Currie grappled the heaviest object particular strengths of the shuttle and the Shuttle Robotic Arm had ever STS-97 launched in November 2000 her crews—sometimes in unplanned manipulated, farther off-center than with one of its heaviest cargos: the heroics. A few such missions are any object had ever been manipulated. massive P6 structural truss; three highlighted to illustrate the high Because of the blocked view of the radiators; and two record-setting drama and extraordinary achievement payload bay (obstructed by Node 1 and solar array wings. At nearly 300 m 2 of the shuttle’s 12-year construction the Pressurized Mating Adapter 2), she (3,229 ft²) each, the solar wings could of the ISS. completed this grapple based on each generate more power than any television cues alone—another first. spacecraft in history had ever used. STS-88—The First Big Step After the FGB was positioned above After docking in an unusual-but- The shuttle encountered the full suite the top of the cargo stack, the shuttle necessary approach corridor that of what would soon be routine used new software to accommodate the arrived straight up from below the ISS, challenges during its first ISS assembly large oscillations that resulted from the Endeavour and her US/Canadian crew mission—Space Transportation System massive off-center object as it moved. gingerly placed the enormous mast high (STS)-88 (1 998). The narrow launch Next, the shuttle crew reconnected the above the Orbiter and seated it with the window required a launch in the middle Androgynous Peripheral Docking first use of the Segment-to-Segment of the night. This required a huge sleep System control box to a second Attachment System. shift. The cargo element (Node 1 with Androgynous Peripheral Docking The first solar wing began to two of the three pressurized mating System cable set and prepared to drive automatically deploy as scheduled, adapters already attached) needed to be the interface between the Pressurized just as the new massive P6 structure warmed in the payload bay for hours Mating Adapter 1 and the FGB. Finally, began to block the communications before launch to survive until the Currie limped the manipulator arm path to the Tracking and Data Relay heaters could be activated after the first while Commander Robert Cabana Satellites. The software dutifully extravehicular activity (EVA). The engaged Endeavour’s thrusters and flew switched off the video broadcast so as rendezvous was conducted with the the Androgynous Peripheral Docking not to beam high-intensity television cargo already erected in a 12-m (39-ft) System halves together. The successful signals into the structure. When the tower above the Orbiter docking mating was followed by a series of video resumed, ground controllers saw mechanism. This substantially changed three EVAs to link the US and Russian a disturbing “traveling wave” that the flight characteristics of the shuttle systems together and to deploy two violently shook the thin wing as it and blocked large sections of the sky as stuck Russian antennas. unfolded. Later, it was determined that seen from the Orbiter’s high-gain This process required continuous lubricants intended to assist in television antenna. operation from two control centers, as deployment instead added enough The rendezvous required the robotic had been practiced during the Mir surface tension to act as a delicate capture of the Russian-American Phase I Program. adhesive. This subtle sticking kept the bridge module: the FGB named fanfolds together in irregular clumps Before departing, the shuttle (with yet Zarya. (Zarya is Russian for “sunrise.” rather than letting them gracefully another altitude-control software “FGB” is a Russian acronym for the unfold out of the storage box. The configuration) provided a substantial generic class of spacecraft—a clumps would be carried outward in reboost to the fledgling ISS. At a press Functional Cargo Block—on which the the blanket and then would release conference prior to the STS-88 mission, Zarya had been slightly customized.) rapidly when tension built up near the Lead Flight Director Robert Castle Due to the required separation of the final tensioning of the array.

150 The Space Shuttle and Its Operations Robert Cabana Colonel, US Marine Corps (retired). Pilot on STS-41 (1990) and STS-53 (1992). Commander on STS-65 (1994) and STS-88 (1998).

Reflections on the International Space Station

“Of all the missions that have been accomplished by the Space Shuttle, the assembly of the International Space Station (ISS) Robert Cabana (left), mission commander, and Sergei Krikalev, certainly has to rank as one of the most challenging and Russian Space Agency mission specialist, helped install equipment successful. Without the Space Shuttle, the ISS would not be aboard the Russian-built Zarya module and the US-built Unity module. what it is today. It is truly a phenomenal accomplishment, especially considering the engineering challenge of assembling “We worked and talked late into the night about what this hardware from all parts of the world, on orbit, for the first time small cornerstone would become and what it meant for and having it work. Additionally, the success is truly amazing international cooperation and the future of exploration when one factors in the complexity of the cultural differences beyond our home planet. I made the first entry into the between the European Space Agency and all its partners, log of the ISS that night, and the whole crew signed it the Canada, Japan, Russia, and the United States. next day. It is an evening I’ll never forget.

“When the Russian Functional Cargo Block, also known as Zarya, which means sunrise in Russian, launched on November 20, 1998, it paved the way for the launch of Space Shuttle Endeavour carrying the US Node 1, Unity. The first assembly mission had slipped almost a year, but in December 1998, we were ready to go. Our first launch attempt on December 3 was scrubbed after counting down to 18 seconds due to technical issues with the Auxiliary Power Units. It was a textbook count for the second attempt on the night of December 4, and Endeavour performed flawlessly.

“Nancy Currie carefully lifted Unity out of the bay and we “Since that berthed it to Endeavour’s docking system with a quick pulse flight, the ISS of our engines once it was properly positioned. With that has grown task complete, we set off for the rendezvous and capture of to reach its full Zarya. The handling qualities of the Orbiter during rendezvous potential as and proximity operations are superb and amazingly precise. a world-class Once stabilized and over a Russian ground site, we got microgravity the ‘go’ for grapple, and Nancy did a great job on the arm research capturing Zarya and berthing it to Unity high above the Orbiter. facility and an This was the start of the ISS, and it was the shuttle, with its engineering unique capabilities, that made it all possible. proving ground “On December 10, Sergei Krikalev and I entered the ISS for for operations the first time. What a unique and rewarding experience it was in space. As it passes overhead, it is the brightest star in the to enter this new outpost side by side. It was a very special 2 early evening and morning skies and is a symbol of the days that we spent working inside this fledgling space station. preeminent and unparalleled capabilities of the Space Shuttle.”

The Space Shuttle and Its Operations 151 Within hours, several astronauts and engineers flew to Boeing Rocketdyne Psychological Support— in Canoga Park, California, to Lessons From Shuttle-Mir to International Space Station develop special new EVA techniques with the spare solar wing. A set of Using crew members’ experiences from flying on Mir long-duration flights, NASA’s tools and at least three alternate plans were conceived in Houston, Texas, and medical team designed a psychological support capability. The Space Shuttle began in California. By the time the crew carrying psychological support items to the International Space Station (ISS) from woke up the next morning, a special the very beginning. Prior to the arrival of the Expedition 1 crew, STS-101 (2000) EVA had been scripted to save the and STS-106 (2000) pre-positioned crew care packages for the three crew members. array. Far beyond the reach of the Subsequently, the shuttle delivered 36 such packages to the ISS. The shuttle Shuttle Robotic Arm, astronauts Joseph transported approximately half Tanner and Carlos Noriega crept slowly of all the packages that were along the ISS to the array base and sent to the ISS during that gently rethreaded the tension cable back onto the pulleys. They used era. The contents were tailored techniques developed overnight in to the individual (and crew). California that were relayed in the Packages contained music form of video training to the on-board CDs, DVDs, personal items, notebook computers. cards, pictures, snacks, Meanwhile, engineers rescripted specialty foods, sauces, holiday the deployment of the second wing to decorations, books, religious minimize the size of the traveling supplies, and other items. waves. The new procedures worked. The shuttle delivered a guitar (STS-105 [2001]), an electronic keyboard (STS-108 As STS-97 departed, the ISS had [2001]), a holiday tree (STS-112 [2002]), external music speakers (STS-116 [2006]), acquired more electric power than any numerous crew personal support drives, and similar nonwork items. As prior spacecraft and was in a robust communications technology evolved, the shuttle delivered key items such as the configuration, ready to grow. Internet Protocol telephones. STS-100—An Ambitious The shuttle also brought visitors and fellow space explorers to the dinner table of Agenda, and an the ISS crews. In comparison to other vehicles that visited the space station, the Unforeseen Challenge shuttle was self-contained. It was said that when the shuttle visited, it was like having your family pull up in front of your home in their RV—they arrived with their own STS -1 00 launched with a four-nation independent sleeping quarters, galley, food, toilet, and electrical power. This made a crew in April 20 01 to deliver the Space Station Robotic Arm and the shuttle arrival a very welcome thing. Raffaello Italian logistics module with major experiments and supplies for the new US Destiny laboratory, The deployment was stopped and a pulled tight enough to stretch the tent which had been delivered in February. bigger problem became apparent. into a strong structure. The whole thing The Space Station Robotic Arm The wave motion had dislodged the was in danger of collapsing, particularly deployed worked well, guided by key tensioning cable from its pulley if the shuttle fired jets to leave. Rocket Canada’s first spacewalker, Chris system and the array could not be fully plumes would certainly collapse the Hadfield. Hadfield reconnected a tensioned. The scenario was somewhat massive wings. If Endeavour left balky power cable at the base of the like a huge circus tent partially erected without tensioning the array, another Space Station Robotic Arm to give the on its poles, with none of the ropes shuttle might never be able to arrive arm the required full redundancy. unless the array was jettisoned.

152 The Space Shuttle and Its Operations Space Station R obotic Arm by using the stage in a “must succeed” EVA. it to return its own delivery pallet to During that EVA, the ISS would briefly Endeavour’s cargo bay. Through a mix be in an interim configuration where of intravehicular activity, EVA, and the shuttle could not dock to the ISS. robotic techniques shared across four On this flight, the ISS would finally space agencies, the ISS and Endeavour achieve the full complement of solar each ended the ambitious mission more arrays and reach its full width. capable than ever. Shortly after the shuttle docked, the ISS main array joint on the starboard side STS-120—Dramatic exhibited a problem that was traced to Accomplishments crushed metal grit from improperly treated bearing surfaces that fouled the By 2007, with the launch of STS -1 20, whole mechanism. While teams worked ISS construction was in its final stages. to replan the mission to clean and Crew members encountered huge lubricate this critical joint, a worse EVA tasks in several previous flights, problem came up. The outermost solar usually dealing with further problems array ripped while it was being in balky ISS solar arrays. A severe deployed. The wing could not be Russian computer issue had occurred retracted or further deployed without during flight STS -11 7 in June of that sustaining greater damage. It would be year, forcing an international problem destroyed if the shuttle tried to leave. Raffaello, the Italian logistics module, flies in the resolution team to spring into action payload bay on STS-100 in 2001. The huge Space Station Robotic Arm while the shuttle took over attitude could not reach the distant tear, and control of the station. Raffaello was successfully berthed crews could not safely climb on the and the mission went smoothly until a STS -1 20, however, was to be one for 160-volt array to reach the tear. software glitch in the evolving ISS the history books. It was already In an overnight miracle of cooperation, computer architecture brought all ISS historic in that by pure coincidence skill, and ingenuity, ISS and shuttle communications to a halt, along with both the shuttle and the station were engineers developed a plan to extend the capability of the ground to commanded by women. Pamela Melroy the Space Station R obotic Arm ’s reach command and control the station. commanded Space Shuttle Discovery using the Orbiter Boom Sensor System Coordinating through the shuttle’s and Peggy Whitson commanded the with an EVA astronaut on the end. communications systems, the station, ISS. Further, the Harmony connecting The use of the boom on the shuttle’s shuttle, and ground personnel organized node would need to be relocated during arm for contingency EVA had been a dramatic restart of the ISS. Astronaut Pamela A major control computer was rebuilt Melroy (left), STS-120 using a payload computer’s hard drive, (2007) commander, while the heartbeat of the station was and Peggy Whitson, maintained by a tiny piece of rescue Expedition 16 software—appropriately called “Mighty commander, pose for a photo in the Mouse”—in the lowest-level computer Pressurized Mating on the massive spacecraft. Astronaut Adapter of the Susan Helms directly commanded the International Space ISS core computers through a notebook Station as the computer. That job was normally shuttle crew members exit the station to assigned to Mission Control. Having board Discovery for rescued the ISS computer architecture, their return trip home. the ISS crew inaugurated the new

The Space Shuttle and Its Operations 153 validated on the previous flight. The new technique using the Space Station Robotic Arm and boom would barely reach the damaged area with the tallest astronaut in the corps—Scott Parazynski—at its tip in a portable foot restraint. This technique came with the risk of potential freezing damage to some instruments at the end of the Orbiter Boom Sensor System. Overnight, Commander Whitson and STS -1 20 Pilot George Zamka manufactured special wire links that had been specified to the millimeter in length by ground crews working with a spare array. In one of the most dramatic repairs (and memorable images) in the history of spaceflight, Parazynski, surrounded by potentially lethal circuits, rode the boom and arm combination on a record-tying fifth single-mission EVA to the farthest edge of the ISS. Once there, he carefully “stitched” the vast array back into perfect shape and strength with the five space-built links. These few selected vignettes cannot possibly capture the scope of the ISS assembly in the vacuum of space. Each shuttle mission brought its own drama and its own major contributions to the ISS Program, culminating in a new colony in space, appearing brighter to everyone on Earth than any planet. This bright vision would never have been possible without the close relationship— and often unprecedented cooperative problem solving—that ISS enjoyed with its major partner from Earth. While anchored to a foot restraint on the end of the Orbiter Boom Sensor System, Astronaut Scott Parazynski, STS-120 (2007), assesses his repair work as the solar array is fully deployed during the mission's fourth session of extravehicular activity while Discovery is docked with the International Space Station. During the 7-hour, 19-minute spacewalk, Parazynski cut a snagged wire and installed homemade stabilizers designed to strengthen the damaged solar array's structure and stability in the vicinity of the damage. Astronaut Douglas Wheelock (not pictured) assisted from the truss by keeping an eye on the distance between Parazynski and the array.

154 The Space Shuttle and Its Operations The International Space Station and Space Shuttle Endeavour, STS-135 (2011)—as photographed by European Space Agency astronaut Paolo Nespoli from aboard the Russian Soyuz spacecraft—following completion of space station assembly. Summary the steam engine, the printing press, shuttle and station grew to where the and fire. The shuttle carried the new generation took up the journey When humans learn how to manipulate modules of this engine of invention, while the accomplished veteran eased any force of nature, it is called assembled them in orbit, provided toward retirement. “technology,” and technology is the supplies and crews to maintain it, and The shuttle’s true legacy does not live fabric of the modern world and its even built the original experience base in museums. As visitors to these economy. One such force—gravity— that allowed it to be designed. is now known to affect physics, astounding birds marvel up close at chemistry, and biology more Over the 12 years of coexistence, these engineering masterpieces, they profoundly than the forces that have and even further back in the days need only glance skyward to see the previously changed humanity, such as when the old Freedom design was ongoing testament to just a portion of fire, wind, electricity, and biochemistry. first on the drawing board, the the shuttles’ achievements. In many Humankind’s achievement of an International Space Station (ISS) twilight moments, the shuttle’s greatest international, permanent platform in and Space Shuttle teams learned a lot single payload and partner—the space will accelerate the creation of from each other, and both teams and stadium-sized ISS—flies by for all to new technologies for the cooperating both vehicles grew stronger as a see in a dazzling display that is brighter nations that may be as influential as result. Like a parent and child, the than any planet.

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