Review of NASA's Earth Science Enterprise Research Strategy for 2000-2010 (2000)

The Earth Science Enterprise (ESE) is one of four science divisions within the National Aeronautics and Space Administration (NASA). Formerly known as Mission to Planet Earth, the ESE deals with space missions and research aimed at observing and understanding the total Earth system and the effects of natural and human-induced changes on the global environment.¹ Approximately 20% of the $1.4 billion ESE budget for FY00 is devoted to research and analysis and 70% is spent on mission development and operations.² The current centerpiece of the ESE is the Earth Observing System (EOS), a series of large, multi-instrument orbital platforms that will measure 24 parameters needed to understand global climate change. Other important ESE missions and studies focus on understanding the dynamics of the solid Earth and natural hazards such as earthquakes and volcanic eruptions, as well as other ocean, atmosphere, and land phenomena.

As originally conceived, the EOS program was intended to include three series of platforms collecting 15 years' worth of data, but in response to congressional direction, external reviews,³,⁴ and a recognition of the need for greater flexibility, NASA has restructured the program. Current plans call for deployment of a suite of smaller spacecraft (systematic observation missions, exploratory missions, and technology demonstration missions) from 2003 to 2010, each carrying a limited number of research instruments, to follow the first series of EOS platforms. The National Research Council (NRC) reviewed the revised mission plans in 1999,⁵ and among that assessment's major recommendations was a call for NASA to develop a “fully integrated science plan.” In its formulation of the administration's FY01 budget proposal, the Office of Management and Budget directed NASA to develop such a plan and to have it reviewed by the NRC before decisions would be made about the content of the Earth science program.

In response to a request from NASA (Appendix A), the Committee to Review NASA's Earth Science Enterprise Science Plan was assembled to review NASA Earth Science Enterprise Research Strategy for 2000-2010, the overview of NASA ESE Science Implementation Plan. The committee was asked to assess the following: (1) the characterization of the issues and primary questions the Plan proposes to address; (2) the criteria and prioritization process described for both the science questions and the definition of mission concepts; and (3) the soundness of the

selection of detailed questions to be pursued, particularly in light of existing NRC reports, such as Global Environmental Change: Research Pathways for the Next Decade. ⁶

The committee's report begins with a summary of findings and recommendations. Section III, Section IV through Section V address, respectively, the primary science issues, the detailed science questions, and NASA's responsibility for answering the detailed questions. The detailed science questions are listed in Appendix B. Section VI discusses the criteria for setting research priorities and for choosing future missions. Appendix C indicates how the criteria discussed in Section VI would be applied in an Announcement of Opportunity for exploratory missions. Section VII discusses strategic elements of a research strategy and provides specific suggestions for improving the Plan. Finally, the committee's conclusions are summarized in Section VIII.

The NASA Earth Science Enterprise Research Strategy for 2000-2010 was written explicitly to delineate the science objectives and questions that NASA can address and a strategy for addressing those questions. Although the document is called a research strategy, it contains elements of both a strategy, in that it identifies the science questions to be answered, and an implementation plan, in that it shows, for example, how the questions are to be answered by measuring specific quantities. In the review that follows, the document is referred to simply as the Plan.

NASA's Earth Science Enterprise addresses research problems related to Earth's natural systems. Its research strategy is organized around five primary Earth system science issues. Each of the primary science issues is followed by a list of detailed science questions and the criteria according to which the questions were ranked. The quantities needed to answer the detailed science questions are summarized in tables, one for each primary science issue. A discussion of ESE research themes (i.e., ESE's program structure) closes the document.

The ESE research program is divided into five disciplinary themes, including oceans and ice, ecosystems, atmospheric chemistry, global water and energy cycle, and solid-Earth science. This mix of disciplines reflects NASA's heritage as a provider of space-based observing systems for addressing a wide range of research problems in the natural sciences. Many of these problems are also relevant to global change research, and NASA has designated certain components of the ESE as its contribution to the U.S. Global Change Research program (USGCRP).7 The global change component of the ESE is the largest agency contribution to the program, accounting for 70% of the total USGCRP budget and 100% of the USGCRP's space-based observation programs. The ESE program structure has significant overlaps with, but also key differences