Explorer offer insufficient support for fellows (Table A.1) and center staff have less of their own time for research, a minimal amount of research time must be guaranteed to ensure the mission expertise. Each mission center operates most effectively when it ensures a balance between mission support and individual research opportunities for the staff based on the size of the operation and the size of the user community.
As the largest astronomy science centers evolve to support their user communities, they naturally become focal points, allowing astronomers to develop strategies for the immediate and long-term future of the areas of astronomy they serve. When a center convenes an annual time allocation committee for reviewing proposals, it will already have a strategy for allocating observatory time and center resources to optimize the overall scientific return. Moreover, the centers host forums in which users and center scientists plan the evolution of the observatory and the center and discuss the scientific opportunities at possible future observatories and their design parameters. Naturally these discussions, and the documents resulting from them, become inputs to strategic decisions in the community and NASA regarding the future of the field.
Due to the wide public appeal of astronomy and the need to improve science education, NASA requires that all science centers support some program of education and public outreach (EPO). These include Web sites (some for the public at large and some for teachers), press releases, teacher training workshops, and EPO grants. The Web sites provide not only images and graphics specific to a mission but also show interplay between scientists and the public through programs such as Ask an Astrophysicist at HEASARC. The level of support for EPO varies with the size of the center (see Appendix A), with large centers having some staff dedicated to EPO and small centers (XMM–Newton, Rossi X-ray Timing Explorer) often sharing resources and staff with their host institutions or umbrella archive centers. Chapter 5 provides a more extensive discussion of education and public outreach activities at the science centers.