Amazon.com description: Product Description: Small spacecraft have become popular for a number of reasons, most prominently the needs to reduce overall cost, be built more quickly, and spread mission risks. NASA has been challenged with crafting a program that continues to produce meaningful science within the constraints of the available budget. Still, pound for pound, small spacecraft are not precisely inexpensive, given the effects of complexity, launch costs, and a greater degree of risk. Historically, science spacecraft have demonstrated increasing reliability, but this trend might not continue, given the shift to managed risk. There is generally less money available to smaller programs to test spacecraft functions and operational procedures prior to launch. Small spacecraft are also generally less robust. Efforts to reduce failure potentials through the application of more reliable components, better testing, and advanced design techniques should receive greater attention. Despite the risks, however, small spacecraft fulfill important roles in earth science, astrophysics, space physics, and planetary science. NASA's current generation of small spacecraft is capable of impressive levels of performance.