1. Introduction / 2. Space system fundamentals / 3. Reviewing a cost estimate / 4. Space vehicle cost crosschecks / 5. Common issues in estimating space programs / 6. Resources for space system cost estimation / 7. Recommendations.

The biennial IAA Symposium on Small Satellites for Earth Observation provides a forum for scientists, engineers and managers to exchange information about planned and on-going programs and missions, and present new ideas, covering small satellite mission objectives as well as technology and management aspects for dedicated earth observation satellites. This volume presents selected contributions of the 5th IAA Symposium on Small Satellites for Earth Observation, April 4 - 8, 2005, organized by the International Academy of Astronautics (IAA), Paris, France, and hosted by the German Aerospace Center (DLR), Berlin, Germany.

Y. Fujimori, Symposium Programme Committee Chair, and Faculty Member, International Space University e-mail: [email protected] M.Rycroft, Faculty Member, International Space University e-mail: [email protected] N. Crosby, International Space University e-mail: [email protected] For the sixth annual ISU Symposium the theme was "Smaller Satellites: Bigger Business? Concepts, Applications and Markets for Micro/Nanosatellites in a New Information World". Thus, the Symposium addressed the crucial question: are small satellites the saviour of space programmes around the world It did this from the unique perspective of the International Space today? University - the interdisciplinary, international and intercultural perspective. This Symposium brought together a variety of people working on small satellites - engineers, scientists, planners, providers, operators, policy makers and business executives, together with representatives from regulatory bodies, from national and international organizations, and from the finance sector, and also entrepreneurs. Discussion and debate were encouraged, based on the papers presented and those published here.

It is within the means of many nations to conduct or participate in cost-effective Earth observation missions. This study provides a definition of cost-effective Earth observation missions and information about background material and organizational support. It discusses cost drivers and provides advice on achieving cost-effective missions and discusses training and education. The conclusions and recommendations range from more general factors, which drive the small satellite mission activities, to visions of future cost-effective Earth observation missions. Complementary to large complex missions, small satellite missions have specific advantages: more frequent missions opportunities and therefore faster return of science and application data, a larger variety of missions and greater diversification of potential users; more rapid expansion of the technical and/or scientific knowledge base; greater involvement of local and small industry. This volume will prove to be a useful source of information to governments, space agencies, academia, and industry.

Remote observations of Earth from space serve an extraordinarily broad range of purposes, resulting in extraordinary demands on those at the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and elsewhere who must decide how to execute them. In research, Earth observations promise large volumes of data to a variety of disciplines with differing needs for measurement type, simultaneity, continuity, and long-term instrument stability. Operational needs, such as weather forecasting, add a distinct set of requirements for continual and highly reliable monitoring of global conditions. The Role of Small Satellites in NASA and NOAA Earth Observation Programs confronts these diverse requirements and assesses how they might be met by small satellites. In the past, the preferred architecture for most NASA and NOAA missions was a single large spacecraft platform containing a sophisticated suite of instruments. But the recognition in other areas of space research that cost-effectiveness, flexibility, and robustness may be enhanced by using small spacecraft has raised questions about this philosophy of Earth observation. For example, NASA has already abandoned its original plan for a follow-on series of major platforms in its Earth Observing System. This study finds that small spacecraft can play an important role in Earth observation programs, providing to this field some of the expected benefits that are normally associated with such programs, such as rapid development and lower individual mission cost. It also identifies some of the programmatic and technical challenges associated with a mission composed of small spacecraft, as well as reasons why more traditional, larger platforms might still be preferred. The reasonable conclusion is that a systems-level examination is required to determine the optimum architecture for a given scientific and/or operational objective. The implied new challenge is for NASA and NOAA to find intra- and interagency planning mechanisms that can achieve the most appropriate and cost-effective balance among their various requirements.