Closing Comments The Shuttle had its faults and its critics, but once on-orbit it was nearly always able to complete its tasks. Its capabilities enabled the fleet of just three Orbiters not merely to visit a space station, albeit a Russian one, but to expand it, resupply it, and deliver and retrieve resident crewmembers. After countless designs and studies stretching back almost five decades and with the Shuttle having been flying for fifteen years, the fleet was given the chance to do what it had been designed to accomplish, namely to assemble and maintain a much larger space sta- tion as an international venture. The legacies of the Shuttle are many and varied across the 135 missions of the thirty-­ year program but paramount in any assessment must be the creation of the International Space Station. Nevertheless the physical assembly of the station is not the full story. As related in these pages, that legacy took an international team many years to achieve and included devising how to prepare the hardware and deliver hundreds of tons of logistics and cargo into space, where most of it was linked together. For just a few days on each mission, crews blended their skills in robotics, spacewalking, and cargo handling into a smooth and almost seamless operation. A great deal was learned, not only by the Russians and Americans, but by the other partners from Shuttle-Mir and various other joint ventures. This cooperative teamwork delivered significant results for each expedition flown to the ISS, even after the Shuttle was retired. Experience from past cooperation, together with new lessons learned from the fiasco of Space Station Freedom and the success of Shuttle-Mir, helped to establish firm foundations for the future. Equally, the experiences of the ISS, both on Earth and in space, are paving the way for further peaceful joint ventures that will take us back to the Moon and eventually on to new endeavors deeper in space. The Shuttle missions to Mir and the ISS had a remarkable record of success, without a single docking failure across either program. The nine Shuttle missions that docked at Mir logged 38 days 14 hr 52 min attached to the station. The thirty-seven ISS assembly mis- sions added another 276 days 11 hr 23 min to this total. Atlantis, Discovery and Endeavour clocked up an impressive total of 315 days 2 hr 15 min (some 45 weeks) docked at the two © Springer International Publishing Switzerland 2017 301 D.J. Shayler, Assembling and Supplying the ISS, Springer Praxis Books, DOI 10.1007/978-3-319-40443-1 302 Closing Comments The First and the Last. The crew of STS-1 who proved the Shuttle concept, and the crew of STS-135 who rounded out the Shuttle’s involvement with the ISS and ended its thirty-year­ program: [l-r] Doug Hurley (STS-135 PLT), Bob Crippen (STS-1 PLT), John Young (STS-1 CDR), Chris Ferguson (STS-135 CDR), Sandra Magnus (STS-135 MS1), and Rex Walheim (STS-135 MS2). stations, completing a vast program of joint operations with eight resident Mir resident crews and seventeen ISS resident crews from 1995 through to 2011. Behind the scenes, there were successes in management and budget, in mission plan- ning and control, in crew selection and training, in hardware development and processing, and in launch and recovery operations. From the missions themselves, valuable experience was gained in rendezvous and docking large vehicles together, extensive robotic opera- tions, planning and executing multiple EVA operations and understanding how to transfer tons of hardware inside and outside a large structure. Now the ISS is complete, the work continues to develop and expand the science pro- gram as an international laboratory that just happens to be situated in Earth orbit. Scores research papers and conference presentations have been issued since the ISS commenced scientific work, essentially in 2001. Details concerning the hundreds of investigations can be found on the websites of the space agencies and their academic and industrial partners. A number of publications focus on the daily activities on the ISS and the research being conducted there, but it is interesting to speculate how the configuration of a space station would have been different if the Shuttle had not been available to assemble it. Ideally, had the Saturn V still been in service, that would have been used to lift far larger elements for a station. Indeed, that seems to be the preferred option even today. The station that we have was designed to be launched using the Shuttle. The irony is that although a larger vehicle is currently being developed in support of future NASA goals in space, there are no plans to expand the ISS further, nor are there any thoughts of replacing it with a more sophisticated ISS Mk-II. But the Chinese have announced their intention to construct their own Mir-class station in the 2020s. Closing Comments 303 The Shuttle was ideally suited to launch, assemble, and supply the multi-modular design of the station originally conceived as Freedom and later morphed into the ISS with something of the Russian Mir-2 proposal thrown in. It will also be fascinating to witness developments, in due course, of whatever comes after the ISS and the ultimate decommis- sioning of the station. Had the Shuttle not been retired in 2011, would it have been economically viable to sustain it as a general duty delivery truck and garbage hauler? Perhaps not. We’ve seen the failure of the effort to develop a commercial Shuttle and with no plans to expand or replace the ISS it would have been difficult to retain the fleet simply for logistics when unmanned vehicles were available for that function. The one advantage that the Shuttle had over its current and planned rivals was its to-orbit and to-Earth mass capability but with no new large payloads to deliver it was indeed time to retire the fleet. The sad part of that decision was that the replacement for the Shuttle was nowhere near ready to fly, and so, like during the six year period between ASTP and STS-1, we will have a pause in American human space flight capability.* The Apollo-Saturn production line by which manned space station operations could have followed on without a break after the initial lunar landings was scrapped to create the Shuttle and a new type of space station. Over forty years after the final Apollo flew the ASTP mission, we again see a complete change of direction with utter confusion of long-­ term plans and the timetables to execute them. Nearly fifty years after the first Apollo astronaut stepped on to the Moon, the ISS is today providing a wealth of research which, it is to be hoped, will assist those on Earth and those lucky few who will eventually set off into deep space. Hopefully the ISS, with its current and future fleets of resupply vehicles, will remain operational for at least another decade. This is testament to the legacy of the Shuttle and the design of the International Space Station. The Space Transportation System was the key to assembling the ISS, but was not required for its further operation. In assembling the ISS, and perhaps in servicing the Hubble Space Telescope, the Shuttle achieved its zenith with tasks that it was always meant to perform. It also offered the opportunity to greatly expand the experience and knowledge of people within the space program, not only flying missions but also on the ground, and more importantly internationally, and at a wide vari- ety of levels of involvement. It is from that wealth of information that, in due course, future generations will benefit. During his career as a NASA astronaut, Leroy Chiao was involved in an expedition to the ISS in 2004. As he recalled two years later, “I had flown three Shuttle missions. I had flown a science Shuttle mission (STS-65, Spacelab IML-2) and I’d gotten to fly on a mis- sion (STS-72) during which I had my first spacewalk, testing tools and assembly tech- niques we ended up using on the space station. On my third Shuttle flight (STS-92) I led an EVA team to help assemble the station. And finally I got to be the Commander of the * As this book goes to press in 2017 we have already seen six years pass since the retirement of the Shuttle fleet, and the first manned flight of the new Orion spacecraft is still some years in the future. 304 Closing Comments The End: July 2011, STS-135 Atlantis captures the final views of the completed ISS from a Space Shuttle. Closing Comments 305 station on a long-duration mission. I flew up and down on a Soyuz, and got to do Russian EVAs as well operate the robotic arm.”† Like many of his colleagues, Chiao would have really loved to fly to the Moon but he recognized that the experiences gained on Shuttle missions would contribute to the data- base of experience and knowledge accumulated over the long series of flights into space. That knowledge will allow future explorers to embark on voyages to the Moon and beyond. When those pioneers explore the solar system, they might reflect that the years of Shuttle operations with space stations were an essential step for international cooperation in the exploration of space. The result of all those decades of effort was suitably summarized by the words of Chris Ferguson, STS-135 CDR, as Atlantis left the ISS on July 19, 2011, to conclude the Shuttle’s involvement in the space station program: When a generation accomplishes a great thing it has the right to stand back for a moment, admire, and take pride in its work.