"New Heights in Reuse: Space Shuttle and the Competition" (Jul '87 cover, Aviation Week & Space Technology)
Chapter 10: Apogee
Though the RS-IC separated from the S-IVC at only 67 kilometers, its five mighty engines imparted enough momentum to it for it to coast to 110 kilometers, just over the Karman line. As the S-IVC and the Orbiter pulled away, and the mild deceleration induced by the J-2S exhaust fell into the noise, the Lifter continued its slow pitch-over maneuver, its nose tilting up toward the black sky. With a loud BANG, the explosive bolts holding the conical interstage to the nose fired, casting the corrugated aluminum shell into the void, drifting slowly, less than a meter per second, away from the Lifter. Even here, aerodynamic forces tugged at both, gently, unpredictably, but the Lifter’s greater momentum reduced their impact on it--the Interstage started to trail behind and drop back.
With the sun hidden by the Lifter’s bulbous nose, the crew got to gaze upon a clear, black daytime sky, flooded with stars. On earth, the sun’s glare and the scattering of light through the atmosphere hides half of the constellations from view for a large chunk of the year, but in space, the crew got to take in a view of the winter constellations in July. With nothing but the red-tinted analog indicators on the Lifter’s control board to pollute the light, Young’s and Crippen’s eyes adjusted just fast enough to see Orion pluck an arrow from his quiver to attack Taurus. Then, the bright blue-white of Earth intruded through their windshield again, first the Gulf of Mexico, then the green-brown curve of Florida and the much lighter blue-green of the Bahamas. The storms that had delayed the launch were followed by a high-pressure system that left clear skies across most of the peninsula--though the tail end of the storm system was just visible, north and east of Grand Bahama. The Lifter’s ascent continued, and even as they coasted further east, their field of view widened, parts of Georgia and Cuba and Alabama entering their view. Crippen and Young each kept one eye out and another on their controls--the auxiliary power units were performing nominally, keeping the control surfaces ready for entry, and the peroxide attitude-control thrusters were all functional. With earth over their heads, the stars under their feet, and faint red light at their fingertips, the crew of Constitution coasted past the official edge of space.
The crew only had so long to focus on the view above them before the fast pace of mission events pulled their attention back into the cockpit. As Young confirmed the vehicle’s alignment in retro attitude, Crippen read off a few screens in front of him, confirming the activation of the control systems for the Student Suborbital Experiment Bay. In the nose, a controller began to feed power to the several small, short-duration experiment packages mounted there. Crippen read off the confirmation that the systems were online, confirmed it with the ground, and moved on to the next item on the checklist. With no further interaction, the controller would run through the rest of the mission, putting the small packages through their paces. They ranged in complexity from high-schoolers’ experiments in microgravity boiling mechanics to university-level experiments in crystal development, brought together by a shared need for a cheap, recoverable launch. Cameras recorded the unique fluid phenomena in this strange regime where viscosity dominated and buoyancy was absent, while geiger counters measured the rate at which cosmic rays penetrated the Lifter’s hull as it climbed. Someday soon, many of these experiments would shift to Orbiter flights or to Spacelab, but, for now, experienced researchers and budding scientists alike took advantage of a system with margin to spare. Endeavour was still climbing to the stars, but STS-8 would produce its first scientific data before the S-IVCs engine even burnt out as Constitution coasted toward the peak of her arc. [/I]
The first launch of Russia’s STS-equivalent sparked fiery new discussions about the next stage of American space exploration. While the STS delivered on many of its promises of flight schedule and cost, the Lifter and Shuttle had been conceptualized as enablers for a broader framework of space exploration and exploitation. While the KH-12 and new commercial satellites like Geostar indicated the ways that Lifter was succeeding,
Mir pointed out the weaknesses of NASA’s space exploration program. Though the new Grumman Multi-Purpose Extension Module expanded the size and duration of Shuttle missions to Spacelab and the capacity of the system for non-Spacelab missions, there was still lack of direction for the next stages of NASA’s human exploration program. It fell to politicians and planners to decide how to respond, and if
Groza and
Uragan’s debut would be the first sparks igniting a new competition in spaceflight.
The American space program had been designed in the 1960s to demonstrate the superiority of the American political and economic system to that of the Soviet Union. It had succeeded in this goal with the landing of Apollo 11 on the Moon in 1969, only for the Soviet Union to (apparently) retake the initiative in the 1970s with the Salyut program, which demonstrated Soviet skill in actual in-space operations. The 1980s saw the pendulum swing back in the other direction, as repeated American successes on all fronts of space activity, from launch to in-space operations to unmanned planetary exploration, seemingly left the Soviet Union in the dust. The debut of
Raskat and
Berkut in 1986, though only matching earlier American achievements, hinted that the Soviet Union was preparing a big push to retake its lead. Though American space advocates tended toward a libertarian-capitalist ideology, there had always been an undercurrent of authoritarianism and admiration for authoritarian methods in both the advocate and entrepreneur communities and among the rank-and-file engineers and managers of the industry. As Charles Lindbergh had once praised the German
Luftwaffe, so his heirs looked at the apparent priority that space conquest got in the Soviet Union with envious eyes. 1986, consequently, saw a flurry of predictions that the Soviet Union was preparing to deploy everything from a permanent space station to solar power satellites to “a colony on the Moon,” in the words of
National Geographic. While in retrospect it boggles the mind that so much was expected in space of a power with so little time left on Earth, it must be remembered that very few intellectuals of the 1970s and 1980s seriously entertained the idea that the Cold War’s end was imminent.
In any case, by 1986, the Space Lifter had been spun off to the Space Transportation Corporation and both the Shuttle and Spacelab were in regular operation. The production lines for both Shuttle and Lifter were closed, with the Orbiter fleet capped at four, plus a set of “structural spares” and the
Pathfinder test airframe, and the Lifter fleet capped at 4, a number deemed suitable for up to 30 flights per year indefinitely. In this comparatively sleepy environment, NASA’s engineers and managers had already begun debating their Next Big Thing.
Berkut’s flight only added some more fuel to a fire already kindled at NASA. In 1984, Congress had authorized a National Commission on Space, including such luminaries as Thomas Paine, Chuck Yeager, and Neil Armstrong, whose purpose was to outline the programs NASA needed to take the next great steps in spaceflight. In early 1986, the NCS published its conclusions: in order to sustainably expand human presence beyond Low Earth Orbit, the key technologies NASA required were electric launch and propulsion technologies, long-duration closed ecosystems, aerobraking, artificial gravity, nuclear power plants for electricity generation, and hypersonic air-breathing propulsion. As it happened, many of these technologies were already under research and development by both NASA and the USAF, the latter of which had picked up with Project Timberwind where NASA had left off with the cancellation of NERVA, and which was researching SCramjet propulsion for the National Aero-Space Plane project. NASA, for its part, was hard at work investigating closed-loop life support technologies and artificial gravity. However, a growing section of NASA’s younger, post-Apollo engineers and managers found a source of disappointment in the NCS’s recommendations: if followed to their conclusion, the only fundamentally new vehicle they’d yield was a Space Transfer Vehicle, the reusable space tug for which Thomas Paine’s original vision in 1970 had called. While no one doubted the utility of such a vehicle, the 1980s had seen the resurgence of a lobby that was interested in the Moon and Mars as human destinations, and the refusal of the NCS to recommend either destination, and the subsequent lackadaisical attitude Congress had taken to funding any of the programs it
had recommended, left a feeling that the other worlds would ever remain
just out of reach. As one attendee at a Case for Mars Conference in Boulder remarked in 1987, “we didn’t get to the Moon when someone said ‘let’s put my lunar module on your heavy lifter.’ We got to the Moon by committing to it and designing an architecture optimized for it. If we keep designing architectures only for orbital operations, that’s all we’ll ever have.” Unfortunately, the NCS was hesitant to recommend either the Moon or Mars as immediate, near-term destinations, owing to the projected cost of an immediate, mostly-expendable effort.
While efforts focused beyond Earth orbit remained distinctly back-burner, efforts directed towards a large, permanent follow-up to Spacelab had been ongoing since President Reagan’s 1984 direction of NASA efforts towards such a project. However, after three years, little real progress had been made. Far from the unified vision which had characterized Project Apollo or the development of the Space Lifter, the American large space station effort remained stranded for more than two years in the blizzard of studies and competing visions which had characterized the early years of the development of the Space Shuttle. A variety of factions had sprung up to critique the station’s purpose and scope. More than the usual squabbles between NASA’s centers over the division of project management, these reflected a deeper struggle over the role and goals of the station project, and the basic tools which would see it carried out. The result was slow progress along a multitude of different tracks.
Johnson Space Center in Houston, coordinator of all manned mission operations, saw themselves as the natural home to any space station development efforts. After all, any manned station with a permanent crew would be controlled from Houston, like Skylab, Shuttle, and Spacelab before it. Moreover, Johnson had long been a focal point for the development of closed loop life support, a key challenge for a permanent space station, and one that they considered unquestionably necessary for missions to Mars. They conceived the NASA response to Reagan’s challenge as a bustling space operations center, with a crew of a dozen or more astronauts working to support laboratories, telescopes, satellite servicing, and the construction, checkout, and maintenance on a fleet of tugs usable for transferring payloads to geostationary orbit, the moon, and beyond. Components would be a mix of Lifter-sized 40-50 metric tons modules and smaller 10-ton modules hauled up by Space Shuttle and regularly rotated home, as with the LDEF or the Grumman MPEM, then assembled under the watchful eye of Shuttle-launched astronauts and augmented with further assembly conducted via EVA.
Marshall was equally enthusiastic about seeing another massive development project come home to its natural roost at the center which had
built Skylab, and supervised the design and assembly of the Space Lifter and Spacelab’s Service Module. Their proposals were largely of similar epic scope and varying role as Johnson’s, but focused more on the larger module sizes, with assembly to be conducted by the modules themselves under autonomous control to minimize risk to astronauts and the number of manned missions required to assemble the station. They even proposed that the station could be launched one large module at a time, first a man-tended power and service module, then growing over time with more habitats, laboratories, and hangars as the needs of the program drove it. The initial module would be similar in concept and function to the Spacelab Pressurized/Service Module split, and one proposal even called for using Spacelab itself as the initial home for checking out the modules as the station was constructed, before casting the older station loose once again.
A dissenting voice on the consensus of a few large 50-ton Lifter-launched modules augmented by specialized 10-ton Shuttle lofted modules came from a faction with membership from both Johnson and Marshall, made up largely of engineers and managers working on the Wet Workshop Evaluation Mission, then aimed for space in 1987. They contended that their project could turn the vast number of expended S-IVC stages into a massive resource for space station construction and space development. Instead of a relatively small crew of a dozen or so, a few “dry” 40-50 ton modules would serve as the foundation for converting numerous larger S-IVC stages, purging them, fitting them with docking facilities, and assembling them into any number of configurations for a large station—or even for more than one in various orbits. Once this resource was tapped, the stream of S-IVC stages lofted would turn into the raw material for laboratories, spin stations, greenhouses, personal quarters, medical facilities, hangars, processing facilities to turn the expended tanks into telescopes or in-space tugs, or even into furnaces to smelt their fellows into raw materials for manifold purposes.
All the manned spaceflight factions sought the support of the space science community. This community, though, was cooler in general on the concepts put forward for such grandiose visions, while divided into its own factions. Biologists specializing in human adaptations to microgravity were excited by the longer crew mission durations a permanent station would enable. After all, the longest missions to Spacelab possible even with the MPEM were barely more than two months, short even compared to final Skylab mission a decade earlier, much less the missions routinely flown by Soviet cosmonauts. Researchers working on experiments which required heavy intervention by astronauts and unsuited for remote monitoring and operation on Spacelab were also excited by the potential of such a station for plant growth, animal studies, and materials processing. For the moment, these researchers were forced to choose between the readily available astronaut time which came from flying in the MPEM aboard Space Shuttle free flights and the longer durations of months or years possible in the isolation of Spacelab. However, while these factions eagerly embraced the concept of a permanent manned station, other factions liked the isolation of Spacelab and the Long Duration Exposed Facility from the intervention of astronauts. For those specializing in crystal growth, physical sciences, ground imaging, and astronomy, Spacelab and the LDEF’s man-tended operation was ideal. Crews in space or on the ground could coordinate the preparation of experiments, then leave them to run on their own, taking away their variable temperatures, atmospheric requirements, and unpredictable vibrations within the station with them. While a larger platform would be valuable, it might not be if it came with the requirement to support a constant crew presence. On the whole, the space science community worried about the way that the many studies from Marshall, Johnson, and the smaller centers focused on the construction and operations of stations, with more efforts spent on the design of windows for hangars for moon tugs than on the options and applications of the laboratories scattered throughout the stations. It was, one scientist remarked, as though the station designers viewed science as some kind of substance which laboratories and instruments produced given an astronaut’s presence, good only to be brought back to the Earth for processing into budgetary funds and new space technologies. Given this perceived attitude, the scientific community was more concerned with ensuring that any new station would not draw effort away from the utilization and utility of existing platforms. This left the scientific community distinctly conservative in the discussions, more concerned with preserving the status quo of Spacelab, Shuttle free flights, and missions like the LDEF than with any faction’s concepts for the large station. As 1986 turned into 1987, the space station program continued to make slow progress in defining those items all the proposals would require, like large docking ports, large solar panel deployment schemes, and environmental control systems, but little real progress in defining a single overall architecture for the station. While NASA continued to debate the direction of American spaceflight focus for the immediate future, Russia continued to up the ante.
Even as
Raskat,
Groza, and
Uragan laid the foundations for a new monument to the scientific and technological prowess of the Workers’ Paradise, the old Soviet manned program began to draw to a close. In order to control costs, the venerable R-7 and the newer Proton family of rockets was scheduled to phase out as
Groza took over more and more of the Soviet space launch requirements. Unlike the American Space Lifter,
Groza could be scaled down to loft only 12 tonnes at a time by leaving off the upper stage and reducing the number of boosters. This meant that all but the smallest Soviet rockets (the Kosmos family, whose LEO payload was only 1.5 tonnes) could be more effectively replaced with variants of the
Raskat-
Groza system--and even that small remaining market was challenged when the Yuzhnoye design bureau proposed to simply fit an upper stage to
Raskat in a side-mounted payload fairing. Proton, whose toxic and corrosive propellants had been raising the ire of Kazakh Communist Party officials for decades, was the first to go. Twin-
Raskat Groza launches could easily and cost-effectively replace Proton for 20-ton class payloads. The
Soyuz family of rockets was to be retained for a few years longer, to maintain Soviet crewed launch capability until the
Uragan spacecraft were ready to pick up the torch, but no further improvements of the
Soyuz design were planned. The
Soyuz-TM, specially optimized for space station operations, had been cancelled earlier in the decade, though its Kurs docking radar would survive to be mounted to the last few
Soyuz-T spacecraft. The last
Soyuz flights of the 1980s, and of the programme as a whole, would seal their own obsolescence by providing final validation for hardware to be integrated to the
Uragans.
Soyuz T-15 was one such mission. This 50-day mission to the space station saw Leonid Kizim and Vladimir Solovyov collect experiments laid out by the previous crew, test electron beam welding techniques in low earth orbit, test a new folding girder design, and, finally, reboost
Salyut to a higher orbit to forestall reentry. Though no further use of the space station was planned, Soviet planners hedged their bets against the chance of a budgetary crisis in Moscow, and left the space station in an orbit not expected to decay until the mid-1990s.
The reboost of
Salyut was not the end of the
Soyuz T-15 mission, however. While they occupied Salyut, the
Raskat-
Groza system had taken to the launch pad again, bearing a new payload--the 40-tonne core module for the new, modular space station
Mir. Injected into the same 51.6-degree orbit occupied by Salyut 7,
Mir’s core module was of a brand new design, optimized for the longer and wider payload fairing of the
Groza rocket. Though
Mir’s life-support, power, and thermal control systems drew heavily on those tested in the
Salyut program, the station’s pressure vessel was of a new design, with two axial docking ports and two more port and starboard ports. The
Mir core module was designed to provide power, communications, thermal control, and crew accommodations for up to 6 cosmonauts on long-term missions, and to support two laboratory modules at a time. The laboratory modules, still under construction in 1986, were similar to the American MPEM, but designed to stay on orbit between missions. They would be carried in an
Uragan payload bay, and attached to the port or starboard docking ports as needed. This would allow
Mir’s scientific capability to be adjusted according to the needs and interests of researchers on Earth, and allow easy upgrades to the laboratories in the very factories in which they were first built.
Soyuz T-15 rendezvoused with
Mir on October 19, 1986, for a brief, two-week stay during which Kizim and Solovyov checked out the station’s life-support, communications, and thermal control systems. Uncooperative station docking systems being a frequent nuisance in the Salyut program, they also repeatedly docked and undocked with the station’s axial docking ports, in order to verify that the rendezvous equipment on the station was functional. The successes proved that the Kurs system did in fact allow
Soyuz to dock without the station actively maneuvering to match.
As the completion of the
Uragan life-support systems dragged on, the decision was made to use up the remaining stock of
Soyuz-T craft to utilize
Mir in the interim. Though the
Mir core module was primarily a service and habitation module, it did have some limited scientific capacity, mostly in the field of space medicine and optical earth observation.
Soyuz T-16 rendezvoused with
Mir on March 5, 1987, carrying Aleskander Laveykin and Yuri Romanenko, who spent 5 months aboard the station studying anti-microgravity countermeasures (including a new design of elastic resistance suit, changed exercise regimes using the new equipment launched on the
Mir core module, and pharmaceutical treatments) and performing extravehicular activities to attach sensors to the exterior of the hull. They also performed basic astronomical observations (with small, simple instruments carried in their
Soyuz) to test the utility of
Mir’s gyroscopic stabilization system, which reduced the reaction-control propellant requirements of the immense space station, at the cost of a high electric power requirement. Among the more revolutionary innovations in life-support on
Mir was a refrigeration-based CO2 scrubbing system, which cooled air until carbon dioxide deposited on a surface for collection, eliminating the need for lithium hydroxide canisters. After some initial hiccups in the third week of the mission, Laveykin and Romanenko repaired the mechanism, which would perform remarkably reliably for the remainder of
Mir’s on-orbit life.
Soyuz T-17 followed T-16 in 1988, bringing Valeri Polyakov and Vladimir Titov to a rendezvous with
Mir on January 7, for a six-month stay. They continued the medical sciences experiments of the T-16 crew, and performed new ones--among their cargo was a specially-designed surgical dummy used to test first-aid techniques for microgravity. Most notable, however, was the rendezvous of the second
Uragan orbiter,
Kryechyet, “Falcon.” Fitted with a docking radar and life-support system, this
Uragan launched unmanned on a
Raskat-
Groza heavy stack, carrying the first of the laboratory modules built for
Mir--the KP
Spektr module, fitted with earth-observation sensors and observation equipment. The first of
Mir’s dedicated laboratory modules,
Spektr brought a massive increase in the scientific capability of the station, giving Polyakov and Titov the ability to perform detailed studies of ground and atmospheric targets, measuring atmospheric gas concentrations and collecting infrared and ultraviolet photographs of the Earth’s surface. Polyakov and Titov also entered
Kryechyet’s flight deck, measuring the atmospheric concentration there and determining that the life-support system was, in fact, functional, and clearing the way for manned launches of the
Uragan orbiters in the years to come.
While the Soviet Union slowly but steadily worked to match and in some cases exceed the progress of the American Space Transportation System and Spacelab efforts, the European Space Agency found its own launch vehicle family, Ariane, something of a disappointment. Though far more reliable than the Europa rockets it replaced, Ariane was far more expensive than the Space Lifter, particularly after the Space Transportation Corporation enacted further cost-saving measures in 1985. While Ariane certainly gave the European Space Agency the ability to launch its own scientific and civil satellites and gave France her own military launch capability, the system found very little interest outside Europe (with the exception of states like Brazil, whose attempts to develop her own satellite launch capability hindered cooperation with the US), and even the United Kingdom had chosen instead to purchase Space Lifter flights for its military payloads.
Though many ESA bureaucrats were content to simply have an independent launch capability, and countries like Germany and Italy preferred to move on to other development programs (such as a permanent “lifeboat” escape vehicle for Spacelab, which would help enable a transition from man-tended to permanently-occupied operations and lay groundwork for future European manned spacecraft), Arianespace and CNES engineers began to study alternative rocket configurations in 1983 that would allow them to reduce costs and compete with STC’s Space Lifter. Recognizing the benefits of reusability demonstrated in the United States, but also recognizing the great strides that the ESA had made in hydrogen-burning rocket engine development and automated control systems, they explored several variants on a purely-European reusable launcher. A range of two and three stage solutions were initially examined, starting in 1982. There were as many approaches within these broad parameters as there were European aerospace firms and institutions. While most converged on hydrogen-oxygen for the core stage, there was disagreement about how to recover the core or whether to bother at all. Proposals for both the core and boosters ranged from fixed wings to folding wings to ballistic reentry to recovery of only the engines, with propulsion ranging from landing rockets to gliding to jets to turboprops, and every conceivable combination. Options for the boosters included solid-propellant (favored by some French engineers, owing to their experience with ballistic missiles), hydrogen, kerosene, hypergollics (favored by the Ariane teams), and pressure-fed natural gas (favored by German engineers based in Stuttgart). By 1984, the range of options began to narrow. The realities of launch from French Guyana forced an emphasis on either water landings (as polar orbit launches required flight directly north, over the open Atlantic), which favored ballistic or airbag landings, or very long-range powered flight to a suitable landing site (sites in the Caribbean and Canada were both considered for the core stage, depending on its exact trajectory). Pressure-fed and solid boosters both lent themselves well to water landings, but conversely their high-thrust, low-specific-impulse characteristics were best suited for the booster stages--which actually could stage close enough to the launch site to fly back.
The logic of multi-stage rocket design began to limit the options. The hydrogen-burning core stage would be the most expensive part of the vehicle and supply most of the delta-v, so it was the most crucial to reuse. It was also undesirable to drop high-performance cryogenic engines into the ocean, so a consensus on a reusable core emerged. While the first design studies had tackled anything from 2 tonnes to 200 tonnes to Low Earth Orbit, a study of the European and global space industry’s actual needs refined the payload target down to 16 tonnes. This would give the new launcher the ability to launch larger geostationary payloads individually, avoiding the logistical headaches of arranging shared launches, while also enabling the launch of an indigenous European manned space capsule, based on the multitude of Spacelab lifeboat projects then under study. The greatest issue remaining to confront was exactly what technology was best suited to developing a reusable launch vehicle that could put 16 tonnes in Low Earth Orbit, a question whose answer eluded program managers for several years.
Alone among the major spacefaring powers, Japan did not found her launch vehicle industry upon a ballistic missile or atomic deterrent program. By law and custom, Japan had renounced such weapons after the carnage of the Second World War. Nevertheless, Japan was quick to join the ranks of spacefaring nations, becoming the fourth nation (after the Soviet Union, United States, and France) to launch its own satellite with the launch of the Osumi satellite on February 11, 1970. Japan’s first two satellite launchers, the Lambda and Mu families, were small and simple solid-fueled rockets, modest by the standards of the gigantic boosters of the Soviet-American Space Race, but they provided a firm foundation for the development of a healthy aerospace sector.
Unlike the French, Japan’s leaders had no illusions about retaking a “rightful place in the sun,” and so cooperation between the Japanese and American governments on space access was comparatively smooth and easy. Japan’s next satellite launch vehicle, the N-I, was based on a license-built Thor IRBM, with a new, Japanese-made upper stage, powered by a liquid-fueled LE-3 engine. The experience gained in the LE-3 development program paved the way for a whole suite of new Japanese engine development programs in the 1970s and 1980s, intended to form the foundation for a fully-reusable Japanese launch vehicle--perhaps even a single-stage-to-orbit spaceplane. Japanese researchers developed a wholly-indigenous hydrogen-burning rocket engine, the LE-5, and conducted research on a host of exotic engine designs, ranging from staged-combustion LH2/LOX engines to air-breathing rocket engines to scramjets.
It was this dynamic and evolving Japanese aerospace sector that attracted interest from American corporations in the 1980s. McDonnell-Douglas, building on its longstanding partnership with Mitsubishi Heavy Industries, took a keen interest in the turboramjet and scramjet research being conducted in Japan, and proposed to use air-breathing engines developed by Ishikawajima-Harima Heavy Industries (whose work built on Aerojet’s research in the 1950s) in their National Aero-Space Plane proposal. Though McDonnell-Douglas did not win the prime contract for NASP, their suggestion to use a Japanese engine design stoked a sudden interest in Japanese propulsion technologies among American aerospace firms. While Japanese businessmen and government officials were reluctant to give much technical access to representatives from Aerojet or Pratt & Whitney, representatives of the more general aerospace firms (McDonnell-Douglas, Martin-Marietta, Boeing, and Grumman) had a much easier time interacting with their Japanese counterparts. American engineers witnessed static-fire tests of a variety of new Japanese hardware, and attended briefings on progress made in more exotic propulsion projects.
The most significant incident during these meetings came in 1986, when Martin-Marietta Vice President of Technical Operations Norm Augustine met with Yohei Mimura to discuss possible Japanese use of Martin-Marietta’s Reusable Launch Vehicle design. To Augustine’s surprise, when he mentioned that Pratt & Whitney and Marshall Space Flight Center had both performed design studies on staged-combustion LH2/LOX engines, Mimura alluded to a staged-combustion-cycle engine already in development and undergoing breadboard component testing, the LE-7. Inquiring further, Augustine and other Martin-Marietta executives learned that Mitsubishi Heavy Industries had been hard at work on a staged-combustion-cycle engine of indigenous design since 1984, intended for the all-Japanese replacement of the N-II rocket. Though they were relative latecomers to cryogenic rocketry, Mitsubishi’s engineers had made great strides in integrating cutting-edge computational fluid simulations to their design process, promising a radical reduction in the cost and development time of the new engine, which they planned to have on the test stand by 1989. They also benefitted from great improvements in metallurgy made between 1970 and 1984, giving them access to better steel and titanium alloys than Pratt & Whitney or Rocketdyne engineers could assume in the waning days of the Apollo program. While they lacked the experience of Soviet engineers, Mitsubishi’s engine designers were the equals of any of their American counterparts.
Japan’s leading aerospace institutions, including NASDA, NAL (the National Aerospace Laboratory), and ISAS (the Institute of Space and Astronautical Sciences), had been intimately involved in evaluating the propulsion systems under development and study by Mitsubishi, Ishikawajima-Harima, and Japanese universities. Inspired by the success of the American Space Lifter and now by the Soviet demonstration of the
Raskat-
Groza system, Japanese engineers and executives had proposed a variety of reusable launch systems, ranging from a miniature Shuttle on top of the proposed H-II expendable rocket to a reusable suborbital sounding rocket to a fully-reusable, air-breathing SSTO program. Martin Marietta’s research during the CRLV program, published openly with the American Institute of Aeronautics and Astronautics, had shown very convincingly that a reusable TSTO would have a lower development cost and comparable operating costs to an SSTO of similar performance--ultimately, the cost of integrating two reusable stages was modest compared to the cost of simply turning the stages around between landing and launch. Martin-Marietta further challenged the conventional wisdom by pointing out that the payload mass fraction of a ballistic, vertical-landing spacecraft could, in fact, exceed that of a winged or lifting-body vehicle, as the horizontal-landing vehicles needed additional structural support to support greater side-loads, whereas vertical-landing craft were already designed to handle axial loads. As a result, a small but growing fraction of Japan’s aerospace establishment was convinced that a fully-reusable, two-stage vehicle would be the most economically viable way forward for Japan’s launch industry. This segment only grew with every milestone passed in the checkout of Martin-Marietta’s Terminal Descent Demonstrator as it prepared for its first flights. Mitsubishi’s revelation of their LE-7 development program had been far from unintentional--rather, it was the first suggestion of an exchange of MHI’s new high-performance rocket engine for Martin-Marietta’s skill with vertical rocket landings.
However, there remained among NASDA’s leadership concerns about committing to an undemonstrated architecture like that proposed by Martin-Marietta, and a reluctance to commit to such a program alone. Augustine’s visit to Japan was an opportunity to measure the possibilities for a partnership with the American company, to evaluate their interest in Japan’s propulsion technologies and the possibility of a relationship similar to that which Mitsubishi in particular and Japanese aerospace in general enjoyed with McDonnell-Douglas. Ideally, NASDA and Mitsubishi wanted to leverage Japan’s strengths in rocket engine development as much as possible, in such a manner that, if the partnership fell through, they would still be able to pivot back to developing their own RLV or returning to the expendable H-II design still under consideration.
The partnership would not be identical, however--whereas the earlier relationship had amounted to Mitsubishi license-building a fully-developed American rocket stage, a joint Japanese-American TSTO would involve the development of new intellectual and physical capital that would not be the sole property of either firm, and there was the possibility of international arms-trafficking regulations keeping such a joint venture out of lucrative government and commercial satellite contracts. A partnership to develop the new vehicles would require the creation of a new, jointly-owned venture. There was precedent for such an organization--in the 1970s, General Electric and Snecma (of France) had created CFM International to manufacture the CFM56 turbofan engine, which used parts made in both the United States and France. CFM International’s engines were manufactured in both Ohio and France, depending on the final buyer for the engines, and both Snecma and GE profited from the exchange of technology and the new markets opened by operating on both sides of the Atlantic.
As Augustine and other Martin-Marietta executives met with their counterparts at Mitsubishi Heavy Industries and with regulators at NASDA, the first outlines of a similar joint venture began to take shape. As 1986 gave way to 1987, an agreement emerged between Mitsubishi Heavy Industries and Martin-Marietta to found a new joint venture--Trans-Pacific Launch Industries, which would jointly develop a TSTO reusable launch vehicle, powered by Japan’s LE-7 and LE-5A rocket engines, but with an airframe and control system developed by Martin-Marietta. The completed vehicles could be assembled in either the United States or Japan (indeed, most likely both, as the CFM56 engine was assembled in both the US and France), while Martin-Marietta retained control over the airframe production line and Mitsubishi focused on the engines. Mitsubishi would supply over 50% of the development capital, while Martin supplied its experience with the TDD.
Formally incorporated in 1987, TPLI would spend the next several years pushing the TDD’s landing software to greater lengths and evaluating designs for the reusable upper stage, while Mitsubishi worked on finishing the LE-7 development process and developing the improved LE-5A variant of its LE-5 rocket engine. In addition to the staged-combustion cycle, the LE-7 had to be capable of deep throttling and very reliable restart in flight, stretching its development cycle into the early 1990s.
American dominance in the field of reusable rockets was no longer unchallenged: the Soviet
Groza system was the first real competition to the Space Transportation System, and Europe, Japan, and even commercial firms were taking the demonstrated benefits of reusability as a pathway for the future of space launch and operations. While this challenge spurred new discussions over the lack of major American space station development or the failure to make a broader plan for the use of Lifter for the development of space, the presence of another competitor in the race only drove home that if NASA was no longer unchallenged, it was unimpeachably dominant. The program had made its 50th launch in 1984, then the 75th mission had inaugurated 1986. Now, as the program closed in on its 100th launch, it was flying as many as 18 missions a year. The main barrier to higher launch rates wasn’t the system’s capabilities but a paucity of payloads, even as the size of commercial satellites grew to fill the Lifter’s Multiple Launch Adaptor. While the Soviets struggled to clear the hurdle of launching two manned
Uragan flights in one year, payload schedulers at NASA, the DoD, and the Space Transportation Corporation made plans for pulling off a similar feat within as little as a week, and to demonstrate two critical roles for the Space Shuttle in the process.
For almost two years, engineers at NASA’s Marshall and Johnson space centers had been collaborating to turn the principles of wet workshop implementation, as developed originally for Skylab’s earliest ancestors, into practice for the Wet Workshop Evaluation Mission, often known by the shorthand “Wetlab”. Specialized modifications had been made to an S-IVC diverted from the main production flow, and a new docking module had been fabricated based on Spacelab and MPEM derived hardware, intended to fly inside the Shuttle for the mission. The S-IVC was fitted with metal mesh partitions and brackets to mount hardware to on orbit, and engineers had spent months designing and testing the ways to fit all the critical systems of a temporary space station into the confines of the Shuttle and the Docking Module. Referencing a new furniture company which was growing around the world, one NASA engineer described it as “trying to design Spacelab as built by IKEA.” However, finally, the hardware was ready and a crew was assigned for training and flight. With an eye to the Public Affairs Office, the mission was assigned the much-anticipated STS-100 mission designation.
At the same time NASA was seeking a public spectacle for their test of a new approach to space operations, the National Reconnaissance Office was eyeing its own new capability. Their KH-12 LUCID electro-optical satellites, with their massive 168-inch main mirrors, were a major improvement over previous KH-11 and KH-9 satellites. However, their capacity came at a price tag staggering compared to previous generations of optical satellites. One of the benefits of the electro-optical design was that film capacity no longer would limit the lifespan of these monsters, but other elements could: failing solar arrays, motors, and batteries, malfunctioning gyroscopes, aging avionics. Moreover, the rapid advance of digital technologies even since the introduction of the KH-11 in 1976 meant that the state of the art for detectors, storage, and controls for satellites had advanced staggeringly even since the KH-12 design was frozen for production in 1983. As the satellites orbited, their capabilities would slowly erode while the state of the art lept ahead.
However, unlike the smaller KH-8 or KH-9 satellites of old, the KH-12 was too expensive to simply dispose of and replace. As Space Shuttle advocates had promoted, there was another way. In 1982, the STS-24 mission to repair the Solar Maximum Mission had demonstrated the repair and enhancement of a flying mission with the assistance of astronauts, and the lesson had not been missed by the KH-12 design team, nor those of their civilian counterparts working on NASA’s Space Telescope project. As the Space Lifter enabled the size and capacity of these two optical systems, the Space Shuttle would allow both to be serviced on orbit. Detectors, avionics, gyroscopes, batteries, and more were examined during design with an eye towards future visits by astronauts on EVA. Quick-connects were developed to link systems intended to be removed and replaced by crews wearing EVA suit gloves and using vacuum-rated tools. Handrails and access panels dotted the outside of the satellites, unlike the bare metal skins of previous generations. Now the planning would pay off.
Two years after its first launch, the time was approaching for the first LUCID platform to be serviced. While west coast Space Shuttle launches typically received less attention than those from Kennedy Space Center, the DoD sought additional shielding from the public eye as a critical national security asset was brought in for a tune up. The first LUCID servicing mission was assigned mission slot STS-101. The planned launch date just days after STS-100 would allow the mission to hide in the public interest NASA’s PAO was focusing on Wetlab. Not for the first time, civilian missions from NASA would serve as cover for the activities of the NRO. Also not for the first time, the best laid plans would go awry.
As NASA’s Public Affairs office drummed up attention on the temporary second American space station mission and the hundredth flight of the Space Lifter, the near-simultaneous launch of a second Shuttle from a second coast west was just one more detail. As intended, the absence of mission details for
Resolution was overshadowed by a rush of stories on the mission and crew of STS-100. While the eyes of those casually interested in spaceflight focused on Florida,
Intrepid was readied in California. However, clouds were on the horizon, both proverbially and literally. A break of bad weather was the first interruption in the schedule, with both missions slipping a week to wait out storms and unsatisfactory winds in Florida. However, in the meantime, further inspections of the STS-100 showed a potential concern with an umbilical plate carrying liquid oxygen to the Space Lifter
Independence.
Destiny’s mission was delayed several more days as the ground crews tested, inspected, and finally removed the entire assembly. It would require servicing before flight. While awaiting a NASA decision on how long the delay might be, Vandenberg launch operations eyed a streak of anticipated bad weather in California. Waiting for
Independence and STS-100 to be ready for Wetlab might mean the delay of STS-101 by more than a month past its originally scheduled date if the close alignment of flights was to be preserved.
Ultimately, leadership made the decision: Wetlab had absorbed enough attention that
Resolution could carry out her servicing mission. While waiting for the originally planned alignment would offer minor benefits in mission secrecy, it would require unwarranted delays. Not for the first time, a Vandenberg launch and a Cape launch would switch their originally planned order. As with the several times the situation had happened before, the STS mission number would stay attached to the two missions even as they switched places. Having the launch sequence in order was of minor benefit given the effort involved in changing hundreds of pages of typewritten documentation, mission patches, briefing notes, and more. While the public continued to take in news on the STS-100 mission to test a new type of station, the actual hundredth launch, STS-101, launched from Vandenberg into thick afternoon clouds on July 23rd, 1987. Less than thirty seconds into the flight,
Intrepid carried
Resolution through the lowest cloud layer, shrouding the mission from the view of the few spectators who had braved intermittent rain showers. Little more was seen before
Intrepid’s return twenty minutes later to a landing on Vandenberg’s runway.
As always, schedule slips were perverse. Almost as soon as Resolution's schedule was no longer tied to it, NASA and STC engineers were able to diagnose and resolve the issues with
Independence's umbilical plate more quickly than anticipated.
Independence and
Destiny belatedly lifted off just two days into
Resolution’s flight, cutting into a cloudless sky in front of thousands of sightseers. The mission reached orbit without incident, the aluminum protrusions within the hydrogen tank having no significant effect on the fluid distribution in flight. The Orbiter, after separating from the upper stage, opened its payload bay, exposing the Docking Module, which filled most of the small bay’s volume. Using the Canadian-built robotic arm, the crew attached the Docking Module to Destiny’s own docking ring and unfurled the small solar array. On the second day of the flight, following a complete check-out of the Docking Module and remote venting of the S-IVC’s residual propellant, the crew docked Destiny and the Docking Module to the mating attachment fitted to the top of the S-IVC’s hydrogen tank. After pressurizing the tank with compressed oxygen and nitrogen, the crew, equipped with eye protection, dust masks, and head-mounted flashlights, entered the cavernous volume of the S-IVC’s hydrogen tank.
Not since Skylab 4 had any crew had so much elbow room in a spacecraft. Pulling themselves down the length of the tank by handholds and mesh floors, the crew inspected all the brackets and attachment points inside the vehicle. Everything seemed to have survived both the launch and exposure to the hard cryogenic propellant the tank had been designed to hold. In one of the more enduringly popular images from the Shuttle program, Commander Charles Bolden, illuminated only by the light filtering in from the Docking Module and his own head-light, jumped gently from the oxygen tank’s bulkhead up the entire length of the hydrogen tank, reaching the Docking Module almost 10 seconds later.
The crew quickly set to work fitting the S-IVC out as a habitable volume. Attaching fluorescent lights to the wall-mounted brackets, they ran power cables from the Docking Module through the open hatch, and set up fans to circulate air between the two spacecraft. Coolant pipes were also run in, to help radiate the crew’s body heat and the heat given off by the electrical systems. Experiment pallets were handled in through the narrow docking hatch, and secured along the walls. This mission had few actual scientific experiments--the pallets were mostly empty--but they proved the concept of moving equipment from the tight confines of the Orbiter to the much roomier Workshop.
While Destiny’s crew could set to work immediately, it had taken most of
Resolution’s lead to even reach rendezvous with the target LUCID platform. Shuttle had always used the massive delta-v capacity required by its integral pusher abort engines to provide some of its own circularization and for orbital maneuvering.
Resolution took this capacity to a new level on STS-101. Instead of boosting payload, the Shuttle carried a smaller payload of barely four metric tons from its initial low, sun-synchronous polar orbit into the highly eccentric orbit of the KH-12 satellites, skimming the lower bounds of the Van Allen belt at just under 1000 km apogee. Even raising its apogee by more than 700 km would leave ample margin to reverse the maneuver for return. Still, the mission in its cloak of secrecy felt remote from Earth as they crept into visual range of the LUCID platform. The KH-12 loomed large, more like a space station than the small satellites Shuttle had previously serviced; the approach to grapple had more in common with docking to Spacelab than the Solar Maximum Mission or recovering the LDEF. Regardless of the challenge,
Resolution’s commander, Richard Lawyer, managed it handily. The crew latched onto the satellite and went to work.
On this early mission, the key capability was to demonstrate any servicing at all and conduct basic inspections impossible by telemetry: future missions using the boosted capacity of the Dual-Engine Upper Stage would be required for major overhaul of the primary instruments. Still, they were able to conduct some small maintenance tasks of great value. One of the KH-12’s gyroscopes had failed in late 1986, and
Resolution had brought a spare. Working together, Lawyer and Mission Specialist Henry Hartsfield extracted the failed unit and installed the replacement. The mission wasn’t solely tasked with upkeep on LUCID, though. On their next EVA, they extracted and replaced one of the platform’s magnetic tape memory modules with one of nearly double the storage capacity. These modules were used to cache images during mapping passes, as data came in from the optic’s CCD arrays faster than it could be downlinked back to Earth. By enhancing the capacity, LUCID would be able to take more pictures and provide better combined imagery of areas critical to national security. The upgraded storage had already been installed on the ground in the latest KH-12, launched earlier in 1987, but now it would be installed on the existing LUCID constellation. The other major task was one in which the National Reconnaissance Office took particular pleasure: demonstrating the capacity to swap some of the platform’s imaging systems. On this flight, they would be pulling the lightest and smallest of the platform’s instruments: the same color mapping camera which had taken the images infamously leaked to
Jane’s. The new system, likewise mounted already to the newest LUCID platform, offered better resolution thanks to a revised CCD array. The leak now would constitute disinformation on actual LUCID capabilities, and the successful swap paved the way for upgrades of other optics once the DEUS became available to boost servicing mission payload.
While the crew of STS-101 were up to their elbows in billions of dollars of critical national-security hardware under near-total media blackout, the crew of STS-100 continued to create an ongoing spectacle aboard Wetlab as they tested variations on the proposed uses of wet workshops as much as possible within the limited mission capacity and duration possible in a Shuttle freeflight without an MPEM. Most excitingly to engineers planning missions to Mars and other destinations, the fifth mission day saw Ehricke’s original vision vindicated when
Destiny used her attitude control thrusters to impart a very slow spin to the docked assembly. Though the center-of-mass of the spacecraft was very close to the Orbiter, the sheer length of the S-IVC’s hydrogen tank meant that even the 1-rpm spin rate achieved produced noticeable acceleration at the oxygen tank’s upper bulkhead. Cameras placed there showed objects falling gently to rest on the bulkhead, and the crew, when they ventured down to provide their own observations, reported feeling a light but noticeable weight.
The S-IVC was de-spun on the sixth day of the mission, shortly before
Destiny separated and returned to Earth. Returning the Docking Module to the payload bay for possible future reuse, the crew separated from the upper stage and deorbited the Shuttle. Several days later, over the Indian Ocean, a pack of solid rocket motors fitted to the base of the empty stage fired, lowering the stage’s perigee to under 100 kilometers over the South Pacific. It joined the rest of the Low Earth Orbit S-IVCs at the bottom of the ocean just hours after.
Resolution had made her return back to Earth without trouble two days earlier, carrying with her the hardware removed from LUCID.
The Wet Workshop experiment had been a technical success, but it had also revealed the shortcomings of the Wet Workshop concept. At the end of the day, the crew of STS-76 had lived and worked in a big, empty aluminum tank. Any attempt to outfit such a stage would have required a much bigger equipment module than the Docking Module or the Orbiter Destiny--there was simply no room in the spacecraft for enough equipment to actually utilize the vast bulk of the hydrogen tank. Compared to the experience of Spacelab four years earlier, the Wet Workshop required much more work to set up and had less ultimate utility. While an Equipment Module could have been built to house equipment for a functional Wet Workshop, such a module would, essentially, be a Space Station itself, rendering the Wet Workshop redundant.
The one unmitigated advantage that the Wet Workshop had over competing Space Station proposals was in the ease with which its length enabled artificial gravity experiments. Though the 1-rpm spin rate of STS-100 allowed only 3% of a G at the base of the hydrogen tank, a 4-rpm rate could provide half a G, while a 5-rpm rate would provide well over 80% of a G--enough to mitigate the deleterious effects of microgravity that had been apparent since Skylab. While this actually acted against the Wet Workshop as an Earth-orbiting Space Station (as it would render the microgravity science experiments then in-vogue impossible), it kept the Wet Workshop popular among planners of interplanetary missions. Most notably, NASA’s Design Reference Mission 1.0 for human missions to Mars would feature an S-IVC retained for the duration of the mission and spun up to address concerns about bone deterioration and interpersonal tensions among the crew.
While Wetlab had added fuel to the fire of debates over future NASA stations and beyond-Earth exploration,
Resolution’s LUCID servicing mission had much more direct impact in the near term. Both missions had demonstrated the capabilities of Shuttle for major overhauls and operations on space hardware, but while
Endeavour’s crews had worked almost entirely in shirtsleeves, assembling small hardware and moving materials,
Resolution’s four-man crew had spent days trading off gruelling EVAs. Also, Wetlab was for the moment a one-off demonstrator. The STS-101 mission profile was one
Resolution and other polar-launched orbiters were due to repeat many times over: a regular servicing schedule for the planned four-satellite KH-12 constellation would require such a mission to launch every year. The demonstration of the repair and even improvement of a delicate optical instrument already on-orbit was also groundwork for Hubble. Though the secrecy involved with LUCID operations meant that the sharing of details was challenging to arrange, NASA had assisted in developing the mission profiles and training for STS-101, as they supported all USAF Shuttle missions, and was able to learn key lessons for Hubble, still more than a year from launch.
The dual successes of STS-100 and STS-101 in 1987 were planned to be followed in 1988 by another feather in the cap of NASA’s unmanned science program, managed through the Jet Propulsion Laboratory. Magellan lifted off on the STS-116 on April 6, 1988, carried on a Lifter-Centaur stack. The Lifter, Liberty, separated neatly from the S-IVC second stage on-time. As they pitched the booster over to point the heavily armored ventral surface forward, to protect the rest from the flame of the second-stage engine, Commander John Blaha and Pilot Richard Richards, both veteran Lifter pilots who had made the trip half-way to orbit before, waited for the slight acceleration that would indicate the successful ignition of the J-2S-2, waiting to complete the flip for the descent burn.
It never came. The RS-IC, nose-up, coasted in free-fall as the seconds ticked by.
“Houston, be advised. We have no second-stage backscatter. Say again, we have no second-stage backscatter.”
"Copy that,
Liberty, we are working it.” Back on on the ground, the voice of the Flight Director came over the main loop, talking over the ongoing discussion between the Lifter and CapCom. “All operators, contingency procedures in effect. Booster operators, watch your data. All other operators, secure all notes. GC, lock the doors." Even as the understanding of the mission failure percolated through the Space Transportation System’s vast network of control and support teams, Launch and Landing Control at Kennedy Space Center stoically prepared for the Lifter’s Return to Launch Site.[/I]
