It began with the desire to ensure a continuous human presence in Earth orbit during the post-Moon landing era. The result of this effort has required a continued access to orbit with the Space Shuttle, giving humans the experience of living and working in space. Through successes and failures, a diverse and highly skilled group of NASA employees and contractors, as well as international collaborators, worked together to accomplish the goal of sustaining a human presence in low-Earth orbit.
While experience in the 1980s tempered earlier predictions in the 1970s about cost-effective operations, the Space Shuttle proved to be a remarkable space access vehicle that served effectively, if not inexpensively, for thirty years of human spaceflight. Its accomplishments were impressive between 1981 and 2011:
- The Space Shuttle successfully met many of the post-Apollo goals for human spaceflight.
- It flew 135 missions over 30 years, with multiple flights per year except during two stand-downs after accidents.
- The shuttle took 335 people into space.
- It delivered satellites, telescopes, and planetary probes. It recovered some satellites for refurbishment.
- It carried research experiments on every flight and full laboratories almost 20 times.
- It opened the door to broad U.S./Russian collaboration in space with the Shuttle/Mir program in the 1990s.
- It made 36 trips to assemble and supply the International Space Station between 1998 and 2011.
Even so, the Space Shuttle did not lower the cost of flight into orbit—its most significant failing—and the Challenger and Columbia tragedies served as grim reminders that spaceflight is always risky.
The Space Shuttle program, while an enormous achievement, has wrought something of a divided legacy. In fundamental ways it may be viewed as both a triumph and a tragedy. As a symbol of American technological excellence, and as a reliable, mature, flexible system on which stunning scientific experiments may be conducted it receives high marks. But the program failed to achieve one of its core objectives, lowering the cost of reaching Earth orbit. Granted, this is an extraordinarily elusive goal, but disappointment over not achieving it has plagued NASA and hampered spaceflight ever since. It remains a goal that must be emphasized in the development of any new vehicle that might eventually replace the Space Shuttle.
On January 5, 1972, Richard Nixon announced the decision to build the Space Shuttle by saying, “I have decided today that the United States should proceed at once with the development of an entirely new type of space transportation system designed to help transform the space frontier of the 1970s into familiar territory, easily accessible for human endeavor in the 1980s and ’90s. This system will center on a space vehicle that can shuttle repeatedly from earth to orbit and back. It will revolutionize transportation into near space, by routinizing it.”
For all of the very real shortcomings of the Space Shuttle Program, there is no question but that Nixon’s statement came to pass with this NASA vehicle. It routinized low-Earth orbit in ways never before possible. Earth orbit is no longer a frontier; we understand exactly what to expect and how effectively to utilize it. The Space Shuttle made that possible. It paved the way for the incorporation of low-Earth orbit into the normal realm of human activities.
The Space Shuttle was never a perfect vehicle and its operation over thirty years had its share of failures, but it certainly was one of the most impressive science and technology efforts in human history. A massively complex system—with more than 200,000 separate components that must work in synchronization with each other and to specifications more exacting than any other technological system in human history—the Space Shuttle must be viewed as a triumph of engineering and excellence in technological management. As such it has been an enormously successful program. The research, development, and operation of the Space Shuttle represented a worthy follow-on to the spectacularly successful Apollo program of the 1960s and early 1970s.