forced in approximately December 2005. At that point the agency will have to weigh the societal benefits of TRMM against both the additional cost and the risk of an uncontrolled reentry if the remaining fuel is used to maintain the satellite’s orbit rather than to guide the spacecraft into the ocean.

The committee’s task focused on the research and operational benefits component of the decision. The committee was not tasked to analyze the risk or cost components, although these components are part of the overall context and thus laid out in Chapter 2. Chapter 3 describes the achievements of TRMM in research and operations to date and Chapter 4 looks to the potential future research and operational applications of TRMM. Chapter 4 differentiates between the potential contributions from a TRMM extension until fuel is depleted to a level that is still sufficient for a controlled reentry or until all fuel is depleted. A series of appendixes provides supporting information that is referenced in the body of the report.


The audience for this report includes NASA and the Japan Aerospace Exploration Agency (JAXA), operational agencies (e.g., the National Oceanic and Atmospheric Administration [NOAA], Department of Defense agencies), Congress (e.g., House Science Committee), the White House Office of Science and Technology Policy and Office of Management and Budget, the scientific community in general, and users in particular.


The committee gathered information using four approaches.

  1. inviting presentations at a workshop on November 8, 2004 (see Appendix C);

  2. promoting and tracking discussion at the workshop (from participants in the room and on the phone [see Appendix D]);

  3. reviewing existing written materials, such as peer-reviewed papers, reports, information from Websites, and letters; and

  4. soliciting input to a Website that posed questions relating to the committee’s phase I task.

The workshop had four sessions (Appendix C) with formal input from 14 people. Approximately 45 people attended the workshop and participated in general discussion. Participants from Japan attended on an open phone line. The formal presentations are available on the Web.1

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