[SAGENAP] and NASA’s Space Science Advisory Committee [SSAC]) available to evaluate proposed collaborations. The Office of Science and Technology Policy could play a useful role in facilitating such interagency cooperation.

International collaboration enables projects that are too costly for the United States alone and enhances the scientific return on projects by bringing in the scientific and technical expertise of international partners. In many cases, international collaboration provides opportunities for U.S. astronomers to participate in major international projects for a fraction of the total cost, as in the case of the European Solar and Heliospheric Observatory (SOHO), XMM-Newton, Planck Surveyor, and FIRST missions, and the Japanese Advanced Satellite for Cosmology and Astrophysics mission. Valuable opportunities for international collaboration exist for smaller missions as well. Collaborations on major projects require the full support of the participating scientific communities, which can be ensured if the projects are among the very highest priorities of the participants, as is the case with ALMA.

The committee affirms the value of international collaboration for ground- and space-based projects of all sizes. International collaboration plays a crucial role in a number of this committee’s recommended initiatives, including the Next Generation Space Telescope, the Expanded Very Large Array, the Gamma-ray Large Area Space Telescope, the Laser Interferometer Space Antenna, the Advanced Solar Telescope, and the Square Kilometer Array technology development, and it could play a significant role in other recommended initiatives as well.

Many mysteries confront us in the quest to understand our place in the universe. How did the universe begin? What is the nature of the dark matter and the dark energy that pervade the universe? How did the first stars and galaxies form? Researchers infer the existence of stellar mass black holes in our galaxy and supermassive ones in the nuclei of galaxies. How did they form? The discovery of extrasolar planets has opened an entirely new chapter in astronomy, bringing a host of

Front Matter (R1-R24)

Executive Summary (1-16)

1. Recommendations (17-50)

2. The Science Behind the Recommendations (51-94)

3. The New Initiatives: Building on the Current Program (95-136)

4. Benefits to the Nation from Astronomy (137-158)

5. The Role of Astronomy in Education (159-176)

6. Policy for Astronomy and Astrophysics (177-208)

References (209-212)

Appendix: Definitions (213-228)

Index (229-246)