ing decade; collectively, they inform the survey’s four key science goals, each of which is considered of equal priority:
Key Science Goal 1. Determine the origins of the Sun’s activity and predict the variations in the space environment.
Key Science Goal 2. Determine the dynamics and coupling of Earth’s magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs.
Key Science Goal 3. Determine the interaction of the Sun with the solar system and the interstellar medium.
Key Science Goal 4. Discover and characterize fundamental processes that occur both within the heliosphere and throughout the universe.
GUIDING PRINCIPLES AND PROGRAMMATIC CHALLENGES
To achieve these four key science goals, the survey committee recommends adherence to the following principles (Chapter 1):
• To make transformational scientific progress, the Sun, Earth, and heliosphere must be studied as a coupled system;
• To understand the coupled system requires that each subdiscipline be able to make measurable advances in achieving its highest-priority science goals; and
• Success across the entire field requires that the various elements of solar and space physics research programs—the enabling foundation comprising theory, modeling, data analysis, innovation, and education, as well as ground-based facilities and small-, medium-, and large-class space missions—be deployed with careful attention both to the mix of assets and to the schedule (cadence) that optimizes their utility over time.
The survey committee’s recommendations reflect these principles while also taking into account issues of cost, schedule, and complexity. The committee also recognizes a number of challenges that could impede achievement of the recommended program: the assumed budget might not be realized or missions could experience cost growth; the necessary activities have to be coordinated across multiple agencies; and the availability of appropriately sized and affordable space launch vehicles, particularly medium-class launch vehicles, is limited.
RECOMMENDATIONS—RESEARCH AND APPLICATIONS
The survey committee’s recommendations are listed in Tables S.1 and S.2; a more complete discussion of the research recommendations—the primary focus of this survey—is found in Chapter 4, along with a discussion of the applications recommendations, while Chapter 7 presents the committee’s vision, premised on the availability of additional funds, of an expanded program in space weather and space climatology. The committee’s recommendations are prioritized and integrated across agencies to form an effective set of programs consistent with fiscal and other constraints. An explicit cost appraisal for each NASA research recommendation is incorporated into the budget for the overall program (Chapter 6); however, for NSF programs, only a general discussion of expected costs is provided (Chapter 5).