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Statement of Task
Background The 2002 NRC decadal strategy study for solar and space physics, The Sun to the Earth—and Beyond, recommended a robust research program for NASA and NSF that would also address the operational needs of NOAA and DOD. The report includes a recommended suite of activities at NASA, which were ordered by priority, presented in an appropriate sequence, and selected to fit within expected resources during the next decade. In early 2004 NASA proposed to adopt major new goals for human and robotic exploration of the solar system that will depend, in part, on basic and applied research in solar and space physics. In view of the fact that the 2002 NRC strategy did not reflect the new exploration goals, a review of the strategy and of the roles that the solar and space physics program should play in support of the new goals is needed.
NASA’s solar and space physics program is conducted by the Sun-Earth Connection (SEC) Division of the Office of Space Science. At the time of the decadal survey, the SEC program included two ongoing mission lines—the Solar-Terrestrial Probes (STP) and the longstanding series of smaller Explorer missions—plus a new series of missions that were planned to create the “Living With a Star” (LWS) program. Following introduction of the new space exploration goals, NASA plans to move forward with the LWS initiative, which focuses on aspects of space weather. However, elements of the STP and Explorer programs may be deferred in view of their being assigned a lower priority in the context of preparations for human missions to the Moon and Mars. The more applied LWS program is seen as necessary to supply information on the environment of space travel between Earth and the Moon and Mars and on how it is controlled by solar activity. The STP and Explorer missions address more basic scientific questions that are not viewed as being as immediately relevant to human exploration.
Nevertheless, OMB and NASA recognize that a strong basic research program is essential to the existence and growth of any applied science, and they have asked the NRC to provide advice on how and where the basic research aspects of the SEC program are needed to ensure that the applications needs of the exploration program are solidly grounded. The need to describe the connection to Exploration was not foreseen during the decadal survey.
The 2002 solar and space physics decadal survey report summarized the state of knowledge about the physics of the Sun, the interplanetary medium, and the space environments of Earth and other solar system bodies, and it posed key scientific questions for further research. The report also set out an integrated research strategy, with prioritized initiatives, for the next decade. The recommended strategy embraced both basic research programs and applied research activities that will enhance knowledge and prediction of space weather effects on Earth. While the report’s attention to space weather issues elaborated on needs and strategies for addressing effects on terrestrial systems and on both civilian and defense spacecraft in Earth orbit, the effects of space weather on future human missions beyond Earth
orbit were not addressed.
Radiation exposure in space will be a significant and serious hazard during any human mission to the Moon or Mars. There are two major sources of radiation: sparse penetrating galactic cosmic radiation, which varies over the solar cycle on time scales of years, and infrequent but intense solar particle events associated with solar storms, which develop over periods of minutes to days. The radiation can lead to both acute and chronic effects, both of which can be life-threatening.
One major challenge to reducing the risk to humans in space from radiation is the need to develop a fundamental understanding of the physical processes at the Sun and in interplanetary space that control the generation and propagation of the radiation. Researchers have made considerable strides in recent years in tackling these problems, but they still remain far from having a reliable capability to model the changing radiation environment, especially from solar events. Having the right mix of basic research aimed at developing the fundamental science and applied research aimed at developing advanced models and forecast tools will be essential.
The 2002 NRC report provides a strong starting point for such a strategic assessment, and OMB and NASA have turned to the NRC to apply that study to planning for future human exploration missions.
Plan In a meeting on April 2, 2004, with the chair of the SSB Committee on Solar and Space Physics, James Burch, and SSB staff officer Art Charo, the chief of the OMB Science and Space Branch, David Radzanowski, and William Jeffreys of OSTP asked that the SSB organize an independent assessment of how the recommendations of the recent NRC report, The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics, would be relevant to NASA’s new space exploration initiative. In subsequent discussions with Richard Fisher, director of NASA’s Sun-Earth Connection division, Fisher agreed that such an assessment was needed.
NASA’s new space exploration goals include plans for an integrated program of human and robotic exploration of the Moon, Mars, and beyond. To prepare for these new challenges, the NRC will provide an independent assessment of the alignment of the agency’s Sun-Earth Connection (SEC) program with the space exploration initiative, especially with respect to the capability of planned space missions to provide data that are needed to improve scientific understanding, monitoring, modeling, and prediction of the hazardous space environment.
An ad hoc committee of the Space Studies Board will be formed to address this request. Specifically, the committee will:
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Analyze the missions and programs that were recommended by the 2002 NRC Solar and Space Physics Survey and assess their relevance to the space exploration initiative; and
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Recommend an effective strategy for high-priority missions that will:
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provide a basic scientific foundation for future space weather prediction capabilities,
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support the needs of the space exploration initiative,
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address the scientific and operational needs of NASA, NOAA, and the DOD, and
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be feasible within realistic resource projections and time scales.
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Schedule An ad hoc committee, which includes some members of the authoring committee of the 2002 solar and space physics decadal survey report, will be formed to conduct the study. The committee will prepare a brief report for delivery to NASA in the third quarter of 2004.