1
Introduction

NASA’s Earth Science Enterprise (ESE) uses remotely sensed observations to develop scientific understanding of the total Earth system and the effects of natural and anthropogenic changes on the global environment. ESE-supported research combines observations and modeling to characterize forcing and response, understand internal variability in Earth’s systems, and ultimately increase the accuracy of a variety of predictions. ESE pursues vigorous research on climate interactions, atmospheric phenomena, terrestrial and oceanic processes and eco-systems, and solid earth processes with the goal of determining their impacts on natural resource availability, resource management, and food production.1

The acquisition of accurate and adequately sampled measurements from space is crucial to ESE objectives, and so ESE sponsors research to develop new measurement approaches and to expand the scope and accuracy of data analyses. A substantial fraction of ESE’s resources is devoted to developing, launching, and operating satellite missions and generating, validating, and distributing scientifically useful products. These products in turn provide crucial input to a variety of scientific, operational, and applications endeavors.

ESE employs four basic types of space mission programs to provide data in support of ESE scientific objectives:

  • Facility-class missions at the observatory level acquire simultaneous, colocated measurements from many instruments; recent examples include the Upper Atmosphere Research Satellite (UARS), Terra, Aqua, and Aura. This class of missions formed the foundation of the Earth Observing System (EOS) program.

  • Facility-class missions and instruments at the dedicated measurement level provide platforms focused on a single measurement set with previously identified value to generate long-duration, accurate data useful for focused scientific investigations and modeling studies; recent examples include Landsat-7, TOPEX/Poseidon, QuikSCAT, TRMM, TOMS, and SAGE.

  • Exploratory missions provide platforms intended to investigate new processes or phenomena or to evaluate innovative measurement approaches; recent examples include GRACE, CALIPSO, CloudSat, and Triana.2 ESE

1  

The 2001 ESE strategic plan, Exploring Our Home Planet: Earth Science Enterprise Strategic Plan, can be found at <http://www.earth.nasa.gov/visions/stratplan/index.html>. A newer version of the plan was in preparation at the time this report went to pre <http://www.earth.nasa.gov/visions/index.html>.

2  

Mission descriptions are available at <http://earthexplorers.gsfc.nasa.gov/project.html> and at the link to ESSP missions, <http://essp.gsfc.nasa.gov/esspmissions.html>. Also see Appendix C, Tables C.3 and C.4, of this report.



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Steps to Facilitate Principal-Investigator-Led Earth Science Missions 1 Introduction NASA’s Earth Science Enterprise (ESE) uses remotely sensed observations to develop scientific understanding of the total Earth system and the effects of natural and anthropogenic changes on the global environment. ESE-supported research combines observations and modeling to characterize forcing and response, understand internal variability in Earth’s systems, and ultimately increase the accuracy of a variety of predictions. ESE pursues vigorous research on climate interactions, atmospheric phenomena, terrestrial and oceanic processes and eco-systems, and solid earth processes with the goal of determining their impacts on natural resource availability, resource management, and food production.1 The acquisition of accurate and adequately sampled measurements from space is crucial to ESE objectives, and so ESE sponsors research to develop new measurement approaches and to expand the scope and accuracy of data analyses. A substantial fraction of ESE’s resources is devoted to developing, launching, and operating satellite missions and generating, validating, and distributing scientifically useful products. These products in turn provide crucial input to a variety of scientific, operational, and applications endeavors. ESE employs four basic types of space mission programs to provide data in support of ESE scientific objectives: Facility-class missions at the observatory level acquire simultaneous, colocated measurements from many instruments; recent examples include the Upper Atmosphere Research Satellite (UARS), Terra, Aqua, and Aura. This class of missions formed the foundation of the Earth Observing System (EOS) program. Facility-class missions and instruments at the dedicated measurement level provide platforms focused on a single measurement set with previously identified value to generate long-duration, accurate data useful for focused scientific investigations and modeling studies; recent examples include Landsat-7, TOPEX/Poseidon, QuikSCAT, TRMM, TOMS, and SAGE. Exploratory missions provide platforms intended to investigate new processes or phenomena or to evaluate innovative measurement approaches; recent examples include GRACE, CALIPSO, CloudSat, and Triana.2 ESE 1   The 2001 ESE strategic plan, Exploring Our Home Planet: Earth Science Enterprise Strategic Plan, can be found at <http://www.earth.nasa.gov/visions/stratplan/index.html>. A newer version of the plan was in preparation at the time this report went to pre <http://www.earth.nasa.gov/visions/index.html>. 2   Mission descriptions are available at <http://earthexplorers.gsfc.nasa.gov/project.html> and at the link to ESSP missions, <http://essp.gsfc.nasa.gov/esspmissions.html>. Also see Appendix C, Tables C.3 and C.4, of this report.

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Steps to Facilitate Principal-Investigator-Led Earth Science Missions has chosen to implement many of the missions in this class through competitive selection of a principal investigator (PI) who is given responsibility for the programmatic and/or scientific leadership of the mission. Data purchase agreements provide an alternative means of obtaining Earth science data when the data are available from the private sector as commercial products; the best recent example is NASA’s purchase of SeaWiFS data from the private SeaStar mission.3 In data purchase agreements, ESE coordinates data product quality (including formats, accuracy, and overall coverage and usage timelines) with private-sector suppliers based on requirements and assessments provided by NASA-appointed science panels. The private company owns and operates the spaceborne hardware and retains commercial rights to the data, which NASA makes available at no cost to scientists for noncommercial research use under terms previously agreed to by NASA and the private-sector suppliers.4 PI-LED MISSIONS AND CHALLENGES Over the last decade, NASA has increasingly solicited proposals for exploratory missions through Announcements of Opportunity (AOs) and implemented them as PI-led projects. In this study, the committee defines a PI-led mission as one with the following characteristics. A single PI, working with his/her team, is responsible for the leadership and successful performance of the mission/investigation. The PI has a large degree of freedom with which to accomplish the proposed objectives with appropriate NASA oversight, which includes reporting requirements at a level that will ensure mission success and agreed upon science return in compliance with the committed cost, schedule, performance, quality, reliability, and safety requirements. The level of NASA’s oversight involvement may vary from mission to mission, depending on the implementing organization and other programmatic considerations.5 Within ESE, PI-led missions have been aggregated into a program called Earth Explorers,6 which is managed for ESE by the Goddard Space Flight Center. The Earth Explorers Program was established by ESE to provide unique, focused, and rapid remotely sensed measurements that address high-priority Earth science questions.7 Measurements acquired by Earth Explorer missions are intended to be complementary to, and not duplicative of, data available from any existing or approved national, international, or commercial satellites. PI-led Earth Explorer missions are competitively selected from proposals submitted in response to an open AO and are managed by a single PI with formal control over, and responsibility for, all aspects of the mission in cooperation with NASA. The selection, implementation, management, and flight of these types of missions present challenges to both ESE and the Earth science community similar to those in other relatively small, rapid, and cost-constrained space missions.8 In addition, however, PI-led Earth Explorer missions, especially those for which the PI is affiliated with a university, face particular difficulties that arise from factors such as a typical lack of mission- and project-management expertise among PIs, weak institutional support bases, management ambiguities resulting from 3   C.R. McClain, M.L. Cleave, G.C. Feldman, W.W. Greg, S.B. Hooker, and N. Kuring, 1998, Science quality SeaWiFS data for global biosphere research, Sea Technology, Sept., pp. 10-16; see also National Research Council (NRC), Space Studies Board, 2000, The Role of Small Satellites in NASA and NOAA Earth Observation Programs, National Academy Press, Washington, D.C., pp. 84-87 (the NRC Small Satellites report). 4   See discussion of SeaWiFS in Appendix D of the NRC Small Satellites report, pp. 84-87. 5   See AO-01-OSS-03, Medium-Class Explorer and Missions of Opportunity: Announcement of Opportunity, Section 3.1. 6   NASA’s Earth Explorers Program is composed of “flight projects that provide pathfinder exploratory and process driven measurements, answering innovative and unique Earth science questions. The program has the flexibility to take advantage of unique opportunities offered through technical innovation by domestic or international cooperative efforts. It provides the ability to investigate processes having unique measurement requirements and which call for quick turnaround and reaction.” See Earth Explorers mission statement at <http://earthexplorers.gsfc.nasa.gov/>. Currently, the components of the Earth Explorers Program are ESSP; the Rapid Spacecraft Developm Office; SORCE, which is in orbit; and Triana, which has been placed in storage indefinitely. 7   See note 6. Also from N. Chrissotimos, NASA Goddard Space Flight Center, presentation to the Committee on Earth Studies, April 25, 2001, p. 3. 8   See NRC, The Role of Small Satellites in NASA and NOAA Earth Observation Programs, 2000.

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Steps to Facilitate Principal-Investigator-Led Earth Science Missions shared responsibilities between the PI and ESE for the ultimate success of the mission, and the need to balance cutting-edge science with training of the next generation of Earth scientists, engineers, managers, and entrepreneurs. Implementation experiences for Earth Explorer missions to date have been decidedly mixed. Several missions has been successfully launched, others are proceeding well toward near-term launch dates, and a few have suffered significant cost and schedule growth, resulting in long delays and ESE-mandated changes in management and/or flight status. These diverse experiences led NASA to ask the Committee on Earth Studies to examine the challenges associated with Earth Explorer missions led by academic PIs, and to evaluate a series of evolutionary programmatic changes in the Earth Explorers Program that have been made by ESE over the last 7 years (see the statement of task, Appendix A). ORGANIZATION OF THIS REPORT This report discusses issues and improvements in three fundamental areas identified by the committee as having high leverage for enhancing PI-led missions: improving the conceptualization of programs under which PI-led missions are executed, enhancing the institutional investments that support these programs, and improving project implementation processes. These areas are discussed in Chapters 3, 4, and 5, respectively. Chapter 6 provides an overall study summary and conclusion. Additional supporting information is contained in the appendixes.