the budget plan for the next five years seems to reflect a continued high priority for science, the fencing-off of the International Space Station at a fixed annual level of $2.1 billion and the Space Station 's essential need for Shuttle support potentially expose NASA's science programs to further budget reductions.

The space technology budget is equally vulnerable. New spacecraft and instrument technologies offer the potential for more productive science missions at lower cost, yet this potential may not be realized without adequate investment in the development of those technologies. Further, the space technology program includes the NASA part of advanced launch vehicle development. Though that program offers to eventually lower costs for transportation to space, it will, for the near future, compete for already limited technology funds.



The early NASA spacecraft programs were implemented relatively rapidly and inexpensively, two-to three-year developments being the norm. As the space sciences matured during the 1970s and 1980s, the expanding knowledge base exerted pressure for more sophisticated measurements and more capable missions. These demands, along with administrative delays, led to greater expense and to longer projects. Where most cradle-to-grave project lifetimes during the Apollo era were a few years, major projects started in the late 1970s through the early 1990s often extended over a decade. By the 1980s, with “flagship” missions costing a billion dollars or more, it became evident that very few such missions could be mounted; that if they were, there would be no room for complementary missions; and that if they failed, their loss would be highly damaging. Higher costs and longer projects meant that individual investigators had fewer flight opportunities. Principal investigators of large projects became less willing to risk compromising quality, capability, or reliability to reduce mission costs. Because new technologies often appear risky, managers were wary of using them on very large space science projects, dampening the infusion of new technologies. Figure 3.1 shows schematically the large mission approach that prevailed at NASA until recently, an approach that led to sporadic, but often ground-breaking or astounding scientific results.

Ultimately, the evolution toward ever larger and longer projects became unsustainable and led to a backlash toward “smaller, faster, cheaper” missions. When combined with today's diminishing budgets, the 25-year ratcheting growth of mission cost and duration has reduced flight opportunities in many disciplines to the point where it has become difficult to maintain scientific vigor. While in some disciplines big missions may be necessary to produce seminal science, small projects are the seed corn in many others. Small projects are incubators of new ideas and of new scientific talent, and the exposure of student scientists and engineers to NASA technologies through small projects is a very effective mechanism for technology transfer.

One early response was the creation of the Planetary Observer concept for a series of somewhat smaller planetary exploration missions to be funded annually at about a constant level, analogous to the Earth-orbital Explorer family. (This concept for an annually funded series was never developed according to original precepts, and only the ill-fated Mars Observer mission was implemented.) Later, advisory groups also concluded that, while some objectives might only be achievable through large missions, a larger number of small missions could offer significant scientific advancements in reasonable time scales while encouraging technological innovation.1,2


Advisory Committee on the Future of the U.S. Space Program, Report of the Advisory Committee on the Future of the U.S. Space Program, December 1990.


Vice President's Space Policy Advisory Board, The Future of the U.S. Industrial Base, November 1992.

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