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5 Summaries of Major Reports This chapter reprints the summaries of Space Studies Board (SSB) reports that were released in 2011 (note that the official publication date may be 2012). Reports are often written in conjunction with other National Research Council boards, including the Aeronautics and Space Engineering Board (ASEB) or the Ocean Studies Board (OSB), as noted. Two reports were released in 2010 but published in 2011—Assessment of Impediments to Interagency Collaboration on Space and Earth Science Missions and Panel Reports—New Worlds, New Horizons in Astronomy and Astrophysics. Their summaries were reprinted in Space Studies Board Annual Report—2010. Report of the Panel on Implementing Recommendations from the New Worlds, New Horizons Decadal Survey was released in December 2010 in prepublication form and is reprinted here. 37
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38 Space Studies Board Annual Report—2011 5.1 Assessing Requirements for Sustained Ocean Color Research and Operations A Report of the OSB and SSB Ad Hoc Committee on Assessing Requirements for Sustained Ocean Color Research and Operations Summary The ocean hosts a fundamental component of Earth’s biosphere. Marine organisms play a pivotal role in the cycling of life’s building blocks such as nitrogen, carbon, oxygen, silica, and sulfur. About half of the global primary production—the process by which CO2 is taken up by plants and converted to new organic matter by photosynthesis—occurs in the ocean. Most of the primary producers in the ocean comprise microscopic plants and some bacteria; these photosynthetic organisms (phytoplankton) form the base of the ocean’s food web. Scientists are exploring how future climate change and sea surface warming might impact the overall abundance of phyto- plankton. A long-term change in phytoplankton biomass would have major implications for the ocean’s ability to take up atmospheric CO2 and support current rates of fish production. Therefore, sustaining a global record of the abundance of phytoplankton and their contribution to global primary productivity is required to assess the overall health of the ocean, which is currently threatened by multiple stresses such as increased temperature and ocean acidification (both due to anthropogenic CO2 emissions), marine pollution, and overfishing. Because the ocean covers roughly 70 percent of Earth’s surface, ships alone cannot collect observations rapidly enough to provide a global synoptic view of phytoplankton abundance. Only since the launch of the first ocean color satellite (the Coastal Zone Color Scanner [CZCS] in 1978) has it been possible to obtain a global view of the ocean’s phytoplankton biomass in the form of chlorophyll. These observations led to improved calculations of global ocean primary production, as well as better understanding of the processes affecting how biomass and productivity change within the ocean basins at daily to interannual time scales. THE OCEAN COLOR TIME-SERIES IS AT RISK Currently, the continuous ocean color data record collected by satellites since the launch of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS, in 1997) and the Moderate Resolution Imaging Spectroradiometer (MODIS, on Terra in 1999 and on Aqua in 2002) is at risk. The demise of SeaWiFS in December 2010 has accentuated this risk. MODIS on Aqua is currently the only U.S. sensor in orbit that meets all requirements (see below) for sustain- ing the climate-quality1 ocean color time-series and products. However, this sensor is also many years beyond its design life. Furthermore, it is no longer possible to rectify problems with the Aqua sensor degradation that were addressed through comparisons with SeaWiFS in the past few years. Therefore, it is uncertain how much longer data from U.S. sensors will be available to support climate research. Although the European Medium-Resolution Imaging Spectrometer (MERIS) meets all the requirements of a successful mission, it is also beyond its design life. Because of the many uncertainties surrounding the next U.S. satellite mission (more specifically the Visible Infrared Imager Radiometer Suite [VIIRS] sensor scheduled to launch fall 2011); data acquired through the VIIRS mission threaten to be of insufficient quality to continue the climate-quality time-series. Even if fully successful, the VIIRS sensor’s capabilities are too limited to explore the full potential of ocean col- or remote sensing. Thus, the U.S. research community is looking to National Aeronautics and Space Administration (NASA) to provide ocean color sensors with advanced capabilities to support new applications and for significant improvements to current research products beyond what is possible with data from SeaWiFS and MODIS or will NOTE: “Summary” reprinted from Assessing Requirements for Sustained Ocean Color Research and Operations, The National Academies Press, Washington, D.C., 2011, pp. 1-7. 1 Climate-quality observations are a time-series of measurements of sufficient length, consistency, and continuity to assess climate variability and change (following NRC, 2004b).
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39 Summaries of Major Reports be possible from VIIRS. However, the Pre-Aerosol-Clouds-Ecosystem (PACE)—the first of NASA’s planned three missions that would advance the capabilities for basic ocean color research—is not scheduled to launch before 2019. Without the ability to sustain high-quality ocean color measurements or to launch next generation sensors with new capabilities, many important research and operational uses are compromised, including the capability to detect impacts of climate change on primary productivity. Therefore, it is imperative to maintain and improve the capabil- ity of satellite ocean color missions at the accuracy level required to understand changes to ocean ecosystems that potentially affect living marine resources and the ocean carbon cycle, and to meet other operational and research needs. Given the importance of maintaining the data stream, the National Oceanic and Atmospheric Administra- tion (NOAA), NASA, the National Science Foundation (NSF), and the Office of Naval Research (ONR) asked the National Research Council to convene an ad hoc study committee to review the minimum requirements to sustain global ocean color radiance measurements for research and operational applications and to identify options to minimize the risk of a data gap (see Box S.1 for the full statement of task). Because the ability to sustain current capabilities is at risk, the report focuses on minimum requirements to sustain ocean color observations of a quality equivalent to the data collected from SeaWiFS. Meeting these requirements will mitigate the risk of a gap in the ocean color climate data record but will be insufficient to explore the full potential of ocean color research and will fall short of meeting all the needs of the ocean color research and operational community. To meet all these needs, a constellation of multiple sensor types2 in polar and geostationary orbits will be required. Note that satellite require- ments for research leading to the generation of novel products would vary depending on the question addressed and are difficult to generalize. THE REQUIREMENTS TO OBTAIN HIGH-QUALITY GLOBAL OCEAN COLOR DATA Satellite ocean color sensors measure radiance at different wavelengths that originate from sunlight and are backscattered from the ocean and from the atmosphere. Deriving the small ocean component from the total radiance measured by satellite sensors is a complex, multi-step process. Each step is critical and needs to be optimized to ar- rive at accurate and stable measurements. Using a set of algorithms (starting with removal of the contribution from the atmosphere, which is most of the signal), radiance at the top of the atmosphere is converted to water-leaving radiance (Lw) and then to desired properties such as phytoplankton abundance and primary productivity. To detect long-term climactic trends from these properties, measurements need to meet stringent accuracy requirements. Achieving this high accuracy is a challenge, and based on a review of lessons learned from the SeaWiFS/MODIS era, requires the following steps to sustain current capabilities: 1. The sensor needs to be well characterized and calibrated prior to launch. 2. Sensor characteristics, such as band-set and signal-to-noise, need to be equivalent to the combined best attributes from SeaWiFS and MODIS. 3. Post-launch vicarious calibration3 using a Marine Optical Buoy (MOBY)-like approach with in situ measurements that meet stringent standards is required to set the gain factors of the sensor. 4. The sensor stability and the rate of degradation need to be monitored using monthly lunar looks.4 5. At least six months of sensor overlap are needed to transfer calibrations between space sensors and to produce continuous climate data records. 6. The mission needs to support on-going development and validation of atmospheric correction, bio-optical algorithms, and ocean color products. 7. Periodic data reprocessing is required during the mission. 2 Type 1: Polar orbiting sensors with relatively low spatial resolution (1 km) with 8 (or many more) wave bands. Type 2: Polar orbiting sensors with medium spatial resolution (250-300 m) and more bands to provide a global synoptic view at the same time as allowing for better performance in coastal waters. Type 3: Hyper-spectral sensors with high spatial resolution (~30m) in polar orbit. Type 4: Hyper- or multi-spectral sensors with high spatial resolution in geostationary orbit. 3 Vicarious calibration refers to techniques that use natural or artificial sites on the surface of Earth and models for atmospheric radiative transfer to provide post-launch absolute calibration of sensors. 4 Monthly lunar looks refers to the spacecraft maneuver that looks at the surface of the moon once a month as a reference standard to determine how stable the sensor’s detectors are. The information from the lunar looks is then used for determining temporal changes in sensor calibration.
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40 Space Studies Board Annual Report—2011 Box S.1 Statement of Task Continuity of satellite ocean color data and associated climate research products are presently at significant risk for the U.S. ocean color community. Temporal, radiometric, spectral, and geometric performance of future global ocean color observing systems must be considered in the context of the full range of research and operational/application user needs. This study aims to identify the ocean color data needs for a broad range of end users, develop a consensus for the minimum requirements, and outline options to meet these needs on a sustained basis. An ad hoc committee will assess lessons learned in global ocean color remote sensing from the SeaWiFS/MODIS era to guide planning for acquisition of future global ocean color radiance data to support U.S. research and operational needs. In particular, the committee will assess the sensor and system requirements necessary to produce high-quality global ocean color climate data records that are consistent with those from SeaWiFS/MODIS. The committee will also review the operational and research objectives, such as described in the Ocean Research Priorities Plan and Implementation Strategy, for the next generation of global ocean color satel- lite sensors and provide guidance on how to ensure both operational and research goals of the oceanographic community are met. In particular the study will address the following: 1. Identify research and operational needs, and the associated global ocean color sensor and system high-level requirements for a sustained, systematic capability to observe ocean color radiance (OCR) from space; 2. Review the capability, to the extent possible based on available information, of cur - rent and planned national and international sensors in meeting these requirements (includ- ing but not limited to: VIIRS on NPP and subsequent JPSS spacecrafts; MERIS on ENVISAT and subsequent sensors on ESA’s Sentinel-3; S-GLI on JAXA’s GCOM-C; OCM-2 on ISRO’s Oceansat-2; COCTS on SOA’s HY-1; and MERSI on CMA’s FY-3); 3. Identify and assess the observational gaps and options for filling these gaps between the current and planned sensor capabilities and timelines; define the minimum observational require- ments for future ocean color sensors based on future oceanographic research and operational needs across a spectrum of scales from basin-scale synoptic to local process study, such as expected system launch dates, lifetimes, and data accessibility; 4. Identify and describe requirements for a sustained, rigorous on-board and vicarious calibration and data validation program, which incorporates a mix of measurement platforms (e.g., satellites, aircraft, and in situ platforms such as ships and buoys) using a layered approach through an assessment of needs for multiple data user communities; and 5. Identify minimum requirements for a sustained, long-term global ocean color program within the United States for the maintenance and improvement of associated ocean biological, ecological, and biogeochemical records, which ensures continuity and overlap among sensors, including plans for sustained rigorous on-orbit sensor inter-calibration and data validation; algo- rithm development and evaluation; data processing, re-processing, distribution, and archiving; as well as recommended funding levels for research and operational use of the data. The review will also evaluate the minimum observational research requirements in the context of relevant missions outlined in previous NRC reports, such as the NRC “Decadal Survey” of Earth Science and Applications from Space. The committee will build on the Advance Plan developed by NASA’s Ocean Biology and Biogeochemistry program and comment on future ocean color remote sensing support of oceanographic research goals that have evolved since the publication of that report. Also included in the review will be an evaluation of ongoing national and interna- tional planning efforts related to ocean color measurements from geostationary platforms.
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41 Summaries of Major Reports 8. A system needs to be in place that can archive, make freely available, and distribute rapidly and efficiently all raw,5 meta- and processed data products to the broad national and international user community. 9. Active research programs need to accompany the mission to improve algorithms and products. 10. Documentation of all mission-related aspects needs to be accessible to the user community. Meeting these requirements would contribute to sustaining the climate-quality global ocean color record for the open ocean. However, further enhancements to sensors and missions, such as higher spectral and spatial resolution, will be required to meet the research and operational needs for imaging coastal waters and for obtaining information about the vertical distribution of biomass or particle load. High frequency sampling (e.g., imagery every 30 minutes for a fixed ocean area), such as can be obtained from geostationary orbit, are desirable enhancements for applications such as ecosystem and fisheries management, as well as naval applications. ASSESSMENT OF CURRENT AND FUTURE SENSORS IN MEETING THESE REQUIREMENTS As Figure S.1 indicates, all current sensors except for Ocean Colour Monitor on-board Oceansat-2 (OCM-2) are beyond their design life. The recent demise of SeaWiFS is also putting into question the future of the MODIS sensors because their recent rapid degradation resulted in a reliance on SeaWiFS data to calibrate the MODIS data. Without this calibration, it is unclear how long MODIS data can be made available at the necessary accuracy. MERIS is a high-quality mission but also beyond its design life. Therefore, the launch of VIIRS planned for fall 2011 comes at a very critical time. Unless there is a successful transition from European Space Agency’s (ESA) MERIS to ESA’s Ocean Land Colour Instrument (OLCI) sensor, and data from OCLI are available immediately, the success and the continuity of the global ocean color time-series will be dependent on the success of the VIIRS mission, because OCM-2 does not collect global data. The research community has long questioned the ability of VIIRS to deliver high-quality data because of a manufacturing error in one of its optical components. Since this issue has been raised, the sensor has been mounted onto its launch vehicle and undergone additional testing and characterization. The most recent tests have resulted in a more optimistic assessment about its performance, and a software solution to overcome part of the optical hardware issue has been proposed. However, based on the committee’s assessment of the overall planning and budgeting, it is currently unlikely that this mission will provide data of sufficient quality to continue the ocean color climate data record. This conclu- sion reflects inadequacies in the current overall mission design and provisions to address all the key requirements of a successful ocean color mission (see above for 10 requirements). In particular, NOAA has not developed a capacity to process and reprocess the data such as is available at NASA. Conclusion: VIIRS/NPP has the potential to continue the high-quality ocean color time-series only if NOAA takes ALL of the following actions: 1. Implement spacecraft maneuvers as part of the mission, including monthly lunar looks using the Earth-viewing port to quantify sensor stability; 2. Form a calibration team with the responsibility and authority to interact with those generating Level 16 products, as well as with the mission personnel responsible for the sensor, to provide the analyses needed to assess trends in sensor performance and to evaluate anomalies; 3. Implement a vicarious calibration process and team using a MOBY-like approach; 5 Raw data is defined as data in engineering units to which new calibration factors can be applied to generate radiance values at the top of the atmosphere. 6 There are five different levels of processing of satellite data: Level 0: Raw data as measured directly from the spacecraft in engineering units (e.g., volts or digital counts). Level 1: Level 0 data converted to radiance at the top of the atmosphere using pre-launch sensor calibration and characterization information adjusted during the life of the mission by vicarious calibration and stability monitoring. Level 2: Data generated from Level 1 data following atmospheric correction that are in the same satellite viewing coordinates as Level 1 data. Level 3: Products that have been mapped to a known cartographic projection or placed on a two-dimensional grid at known spatial resolution. Level 4: Results derived from a combination of satellite data and ancillary information, such as ecosystem model output.
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42 Space Studies Board Annual Report—2011 ??? ??? ??? ??? 10-year ??? Data Gap ??? ??? ??? Data Gap? FIGURE S.1 The launch sequence of past, current, and planned ocean color sensors in polar orbit are displayed. The sensors still operational are shown with a one-sided arrow; the hatched area indicates when a sensor is beyond its design life. The gray shaded S.1 (and 4-1).eps background indicates a data gap in the past and a potential data gap if MODIS sensors and MERIS cease today. The question marks are used to indicate sensors that either do with added minimum elements or are vulnerable to changes in fund - bitmap not yet meet the vector requirements ing allocation. Future sensors are shown having either a five- or seven-year lifetime, according to their individual specifications. CZCS: Coastal Zone Color Scanner; OCTS: Ocean Color and Temperature Scanner; SeaWiFS: Sea-viewing Wide Field-of-view Sensor; OCM/OCM-2: Ocean Colour Monitor; MODIS-Terra/MODIS-Aqua: Moderate Resolution Imaging Spectroradiometer on Terra/Aqua, respectively; MERIS: Medium Resolution Imaging Spectrometer; GLI: Global Imager; VIIRS: Visible Infrared Imager Radiometer Suite; OLCI: Ocean Land Colour Instrument onboard Sentinel-3; PACE: Pre-Aerosol-Clouds-Ecosystem; GCOM-C: Global Change Observation Mission for Climate Research; JPSS: Joint Polar Satellite System. SOURCE: Based on data from http://www.ioccg.org/sensors_ioccg.html. 4. Implement a process to engage experts in the field of ocean color research to revisit standard algo - rithms and products, including those for atmospheric correction, to ensure consistency with those of heri - tage instruments and for implementing improvements; 5. Form a data product team to work closely with the calibration team to implement vicarious and lunar calibrations, oversee validation efforts, and provide oversight of reprocessing; and 6. Provide the capability to reprocess the mission data multiple times to incorporate improvements in calibration, correct for sensor drift, generate new and improved products, and for other essential reasons. Conclusion: If these steps are not implemented, the United States will lose its capability to sustain the cur- rent time-series of high-quality ocean color measurements from U.S. operated sensors in the near future, because the only current viable U.S. sensor in space (MODIS-Aqua) is beyond its design life. Regardless of how well VIIRS performs, it has only a very limited number of ocean color spectral bands and thus cannot provide the data required by the research community for advanced applications. Under ideal conditions of international cooperation, data from U.S. and non-U.S. sensors planned for the future could be made readily available to meet the many needs for research and operations, but ideal conditions are difficult to negotiate for many
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43 Summaries of Major Reports complicated reasons. The European MERIS mission is currently providing high-quality global data, albeit with somewhat less frequent global coverage owing to its narrower swath as compared to the U.S. missions. The Euro- pean Space Agency (ESA) expects MERIS will continue to operate until its follow-on sensor (OLCI) is launched on ESA’s Sentinel-3 platforms in 2013. ESA, NASA and NOAA have ongoing discussions about full exchange of MERIS mission data, including raw satellite data and calibration data. The Indian space agency launched the OCM-2 sensor in 2009. OCM-2 has excellent technical specifications, but to date, data access is very limited. Furthermore, OCM-2 is not a global mission; its data collection priority focuses on the Indian Ocean. The Japanese space agency is planning an advanced ocean color sensor, Second-Generation Global Imager (S-GLI), for launch in 2014 that has high potential based on its technical specifications. Conclusion: Under the following conditions non-U.S. sensors can be viable options in replacing or augment- ing data: 1. A U.S. program is established to coordinate access to data from non-U.S. sensors, including full access to pre-launch characterization information and timely access to post-launch Level 1 or Level 0 data, and direct downlink for real-time access; and 2. This program includes sufficient personnel and financing to collect independent calibration and validation data, assess algorithms and develop new algorithms as required, produce and distribute data products required by U.S. users, support interactions among U.S. research and operational users in govern - ment, academia and the private sector, and has the capability to reprocess data from U.S. missions (e.g., MODIS, SeaWiFS) as well as the non-U.S. sensors to establish a continuous time-series of calibrated data. The committee finds that non-U.S. sensors can be viewed as a source of data to complement and enhance U.S. missions. For example, merging calibrated data from multiple sensors, particularly if the sensors have different equatorial crossing times, can provide much more complete global coverage than is possible from a single sensor. Mean coverage from a single sensor averages about 15 percent of the global ocean per day, owing to cloud cover and limitations imposed by swath width and orbit characteristics. Daily coverage can be increased by merging data from multiple sensors, if they are in complementary orbits. Furthermore, sensors such as MERIS, OLCI, and OCM-2 have much better capabilities—including higher spatial and spectral resolution—for imaging coastal waters than current U.S. sensors or VIIRS. Routine access to the data from these non-U.S. sensors, particularly MERIS and OLCI, is essential to advance the research and operational uses of ocean color data for U.S. coastal applications. OCM-2 has potential but is not currently operated for global observations. Finally, non-U.S. space agencies are taking some of the development risk for new approaches to ocean color data collection. For example, South Korea in 2010 became the first country to put an ocean color imager into geostationary orbit (viewing the East China Sea), and thus will help the international user community understand the potential of this approach, including the capability to view the same ocean area about every 30 minutes during daylight hours. MINIMIZING THE RISK OF A DATA GAP The risk of a data gap in the U.S. ocean color time-series is very real and imminent because MODIS is not likely to deliver high-quality data for much longer. Many issues remain unresolved regarding the VIIRS missions, and the next U.S. ocean color mission, NASA’s Pre-Aerosol-Clouds-Ecosystem (PACE) mission, will not launch before 2019. To minimize this risk, the principal recommendation of the committee is: Recommendation: NOAA should take all the actions outlined above to resolve remaining issues with the VIIRS/NPP. In addition, NOAA needs to fix the hardware problems on the subsequent VIIRS sensors and ensure all the above actions are incorporated into the mission planning for the subsequent VIIRS launches on JPSS-1 and JPSS-2. Taking these steps is necessary to generate a high-quality dataset, because VIIRS is the only opportunity for a U.S. ocean color mission until the launch of NASA’s PACE mission, currently scheduled for launch no earlier than 2019. In addition, if MERIS ceases operation before Sentinel-3A is launched in 2013, VIIRS/NPP would be the only global ocean color sensor in polar orbit.
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44 Space Studies Board Annual Report—2011 To develop quality ocean color products requires highly specialized skill and expertise. Currently, the NASA Ocean Biology Processing Group (OBPG) at Goddard Space Flight Center (GSFC) is internationally recognized as a leader in producing well-calibrated, high-quality ocean color data products from multiple satellite sensors. NOAA currently lacks the demonstrated capacity to readily produce high-quality ocean color products and provide the comprehensive services currently available from the OBPG, although NOAA is in the process of building its capacity. For example, although NOAA’s National Climate Data Center (NCDC) plans to archive a climate-level7 radiance data record, it is unclear how NOAA can generate the products or make them easily accessible to U.S. and foreign scientists. Both NASA and NOAA support ocean color applications, with NASA focused primarily on research and development and NOAA focused on operational uses. Because both agencies have a strong interest in climate and climate impacts, they share a common interest in climate data records.If NOAA builds its own data processing/ reprocessing group, two independent federal groups will then be developing ocean color products and climate data records. While this can be justified given the distinct missions of NOAA and NASA, it can also raise problems when discrepancies appear in the data records. Moreover, the committee anticipates major challenges to generating high-quality products from the VIIRS/NPP data, which call for involving the expertise currently only available at NASA’s OBPG. For these reasons, the committee concludes the following: Conclusion: NOAA would greatly benefit from initiating and pursuing discussions with NASA for an ocean color partnership that would build on lessons learned from SeaWiFS and MODIS, in particular. 8 Recommendation: To move toward a partnership, NASA and NOAA should form a working group to deter- mine the most effective way to satisfy the requirements of each agency for ocean color products from VIIRS and to consider how to produce, archive, and distribute products of shared interest, such as climate data records, that are based on data from all ocean color missions. This group should comprise representatives from both agencies and include a broad range of stakeholders from the ocean color research and applica - tions community. Based on its review of previous ocean color missions, the committee concludes that a long-term national pro- gram to support ocean color remote sensing involves multiple agencies—NOAA and NASA in particular, with input from the academic research community, and continuous funding that goes beyond the lifetime of any particular satellite mission. Such a mechanism is required to ensure that: 1. Continuity is achieved and maintained between U.S. and non-U.S. satellite missions; 2. Lessons learned from previous missions are incorporated into the planning for future missions; 3. Mission planning and implementation are timed appropriately to ensure continuity between satellite missions; 4. Capability for data processing and reprocessing of U.S. and non-U.S. missions is maintained; and 5. Planning for transition from research to operation occurs early for each mission and is implemented seam- lessly via cooperation and interaction between government, academic, and private-sector scientists. Recommendation: To sustain current capabilities, NOAA and NASA should identify long-term mechanisms that can: • Provide stable funding for a MOBY-like approach for vicarious calibration; • Maintain the unique ocean color expertise currently available at NASA’s OBPG over the long term and make it available to all ocean color missions; • Nurture relations between NASA and NOAA scientists so that both agencies meet their needs for ocean color data in the most cost-effective manner and without needless duplication; 7 Climate-level means repackaged data to look like a MODIS granule and all metadata repackaged accordingly to ease the reprocessing of the Level 0 data. 8 Consistent with the conclusions and recommendations of “Assessment of Impediments to Interagency Collaboration on Space and Earth Science Missions” (NRC, 2010).
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45 Summaries of Major Reports • Establish and maintain validation programs, and maintain and distribute the data over the long term; • Provide the planning and build the will for continuity in the satellite missions over the long term; and • Sustain the viability of the scientific base by supporting research and training. The committee envisions that such a mechanism could be a U.S. working group modeled after the International Ocean Colour Coordinating Group (IOCCG). The establishment of a working group with representation from all the interested federal agencies, from U.S. academic institutions and the private sector could provide the necessary long-range planning to meet the needs of U.S. users, provide external advice to the individual missions, interact with foreign partners, and develop consensus views on data needs and sensor requirements. CONCLUSION The diverse applications of, and future enhancements to, ocean color observations will require a mix of ocean color satellites in polar and geostationary orbit with advanced capabilities. Although the three missions described in NASA’s Decadal Survey (Aerosol-Cloud-Ecosystem/Pre-Aerosol-Cloud-Ecosystem, Geostationary Coastal and Air Pollution Events [GEOCAPE], and Hyperspectral Infrared Imager [HyspIRI]) will potentially provide many advanced capabilities, meeting all user needs within the next decade will likely surpass the capability of a single space agency or nation. Conclusion: U.S. scientists and operational users of satellite ocean color data will need to rely on multiple sources, including sensors operated by non-U.S. space agencies, because the United States does not have approved missions to sustain optimal ocean color radiance data for all applications. Recommendation: NOAA’s National Environmental Satellite, Data, and Information Service and NASA’s Science Mission Directorate should increase efforts to quickly establish lasting, long-term data exchange policies, because U.S. users are increasingly dependent on ocean color data from non-U.S. sensors. The IOCCG presents an effective body through which NASA and NOAA can engage with foreign space agencies and develop a long-term vision for meeting the research and operational needs for ocean color products. Through the IOCCG, space agencies can identify options for collaborations and approaches mutually beneficial to all interested parties. The group has been active in communicating user needs and is working with the Committee on Earth Observation Satellites (CEOS) to develop plans for the Ocean Colour Radiometry Virtual Constellation9 (OCR-VC). In the long term, international partnerships will be needed to sustain the climate-quality global ocean color time-series, and at the same time, to advance ocean color capabilities and research. 9 A virtual constellation is a set of space and ground segment capabilities operating together in a coordinated manner; in effect, a virtual system that overlaps in coverage in order to meet a combined and common set of Earth Observation requirements. The individual satellites and ground segments can belong to a single or multiple owners.
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46 Space Studies Board Annual Report—2011 5.2 Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era A Report of the SSB and ASEB Ad Hoc Committee for the Decadal Survey on Biological and Physical Sciences in Space Summary SCIENCE AND EXPLORATION More than four decades have passed since a human first set foot on the Moon. Great strides have been made since in our understanding of what is required to support an enduring human presence in space, as evidenced by progressively more advanced orbiting human outposts, culminating in the current International Space Station (ISS). However, of the more than 500 humans who have so far ventured into space, most have gone only as far as near-Earth orbit, and none have traveled beyond the orbit of the Moon. Achieving humans’ further progress into the solar system has proved far more difficult than imagined in the heady days of the Apollo missions, but the potential rewards remain substantial. Overcoming the challenges posed by risk and cost—and developing the technology and capabilities to make long space voyages feasible—is an achievable goal. Further, the scientific accomplishments required to meet this goal will bring a deeper understanding of the performance of people, ani - mals, plants, microbes, materials, and engineered systems not only in the space environment but also on Earth, providing terrestrial benefits by advancing fundamental knowledge in these areas. During its more than 50-year history, NASA’s success in human space exploration has depended on the agency’s ability to effectively address a wide range of biomedical, engineering, physical science, and related obstacles—an achievement made possible by NASA’s strong and productive commitments to life and physical sciences research for human space exploration, and by its use of human space exploration infrastructures for scientific discovery. 1 This partnership of NASA with the research community reflects the original mandate from Congress in 1958 to promote science and technology, an endeavor that requires an active and vibrant research program. The committee acknowledges the many achievements of NASA, which are all the more remarkable given budgetary challenges and changing directions within the agency. In the past decade, however, a consequence of those challenges has been a life and physical sciences research program that was dramatically reduced in both scale and scope, with the result that the agency is poorly positioned to take full advantage of the scientific opportunities offered by the now fully equipped and staffed ISS laboratory, or to effectively pursue the scientific research needed to support the development of advanced human exploration capabilities. Although its review has left it deeply concerned about the current state of NASA’s life and physical sciences research, the Committee for the Decadal Survey on Biological and Physical Sciences in Space is nevertheless con - vinced that a focused science and engineering program can achieve successes that will bring the space community, the U.S. public, and policymakers to an understanding that we are ready for the next significant phase of human space exploration. The goal of this report is to lay out steps whereby NASA can reinvigorate its partnership with the life and physical sciences research community and develop a forward-looking portfolio of research that will provide the basis for recapturing the excitement and value of human spaceflight—thereby enabling the U.S. space program to deliver on new exploration initiatives that serve the nation, excite the public, and place the United States again at the forefront of space exploration for the global good. This report examines the fundamental science and technology that underpin developments whose payoffs for human exploration programs will be substantial, as the following examples illustrate: NOTE: “Summary” reprinted from Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era, The National Academies Press, Washington, D.C., 2011, pp. 1-10. 1 These programs’ accomplishments are described in several National Research Council (NRC) reports—see for example, Assessment of Directions in Microgravity and Physical Sciences Research at NASA (The National Academies Press, Washington, D.C., 2003).
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47 Summaries of Major Reports • An effective countermeasures program to attenuate the adverse effects of the space environment on the health and performance capabilities of astronauts, a development that will make it possible to conduct prolonged human space exploration missions. • A deeper understanding of the mechanistic role of gravity in the regulation of biological systems (e.g., mechanisms by which microgravity triggers the loss of bone mass or cardiovascular function)—understanding that will provide insights for strategies to optimize biological function during spaceflight as well as on Earth (e.g., slowing the loss of bone or cardiovascular function with aging). • Game changers, such as architecture-altering systems involving on-orbit depots for cryogenic rocket fuels, an example of a revolutionary advance possible only with the scientific understanding required to make this Apollo-era notion a reality. As an example, for some lunar missions such a depot could produce major cost savings by enabling use of an Ares I type launch system rather than a much larger Ares V type system. • The critical ability to collect or produce large amounts of water from a source such as the Moon or Mars, which requires a scientific understanding of how to retrieve and refine water-bearing materials from extremely cold, rugged regions under partial-gravity conditions. Once cost-effective production is available, water can be transported to either surface bases or orbit for use in the many exploration functions that require it. Major cost savings will result from using that water in a photovoltaic-powered electrolysis and cryogenics plant to produce liquid oxygen and hydrogen for propulsion. • Advances stemming from research on fire retardants, fire suppression, fire sensors, and combustion in microgravity that provide the basis for a comprehensive fire-safety system, greatly reducing the likelihood of a catastrophic event. • Regenerative fuel cells that can provide lunar surface power for the long eclipse period (14 days) at high rates (e.g., greater than tens of kilowatts). Research on low-mass tankage, thermal management, and fluid handling in low gravity is on track to achieve regenerative fuel cells with specific energy greater than two times that of advanced batteries. In keeping with its charge, the committee developed recommendations for research fitting in either one or both of these two broad categories: 1. Research that enables space exploration: scientific research in the life and physical sciences that is needed to develop advanced exploration technologies and processes, particularly those that are profoundly affected by operation in a space environment. 2. Research enabled by access to space: scientific research in the life and physical sciences that takes advan- tage of unique aspects of the space environment to significantly advance fundamental scientific understanding. The key research challenges, and the steps needed to craft a program of research capable of facilitating the progress of human exploration in space, are highlighted below and described in more detail in the body of the report. In the committee’s view, these are steps that NASA will have to take in order to recapture a vision of space exploration that is achievable and that has inspired the country, and humanity, since the founding of NASA. ESTABLISHING A SPACE LIFE AND PHYSICAL SCIENCES RESEARCH PROGRAM: PROGRAMMATIC ISSUES Research in the complex environment of space requires a strong, flexible, and supportive programmatic struc - ture. Also essential to a vibrant and ultimately successful life and physical sciences space research program is a partnership between NASA and the scientific community at large. The present program, however, has contracted to below critical mass and is perceived from outside NASA as lacking the stature within the agency and the com - mitment of resources to attract researchers or to accomplish real advances. For this program to effectively promote research to meet the national space exploration agenda, a number of issues will have to be addressed. Administrative Oversight of Life and Physical Sciences Research Currently, life and physical science endeavors have no clear institutional home at NASA. In the context of a programmatic home for an integrated research agenda, program leadership and execution are likely to be produc -
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60 Space Studies Board Annual Report—2011 HOW TO COMMUNICATE Social Media A major theme of the workshop was the tremendous ongoing changes in traditional media, especially the de- cline of newspapers and the reduction in the number of print and broadcast science reporters, versus the emergence of the new social media. Discussion focused on how the space community is or is not taking advantage of social media tools like Twitter and Facebook to communicate within their own communities and with the public. Two of the scientists, Hammel and Seager in particular, lauded the benefits of the social media and exhorted their colleagues to at least try it. The reluctance on the part of many of their colleagues was palpable, however. Alan Dressler, astronomer at the Observatories of the Carnegie Institution and an SSB member, said that social media was worrisome because of all the “kook mail” he gets. Moore agreed, saying that the climate science community was not embracing it because of the “hate tweets” they have been getting since Climategate. Nicholson was the most ardent of the communicators in encouraging scientists to at least try the various types of social media to see if any meet their goals. If a particular platform does not achieve those goals after a trial pe- riod, she advised them to stop and try another platform. She said social media can provide visibility and promotion, community and networking, monitoring of conferences (such as this workshop), testing the waters for different ideas, keeping a finger on the pulse of what is happening, and improving writing skills, especially brevity. The main advantage of social media, she repeatedly emphasized, is that it allows “many to talk to many” instead of “one to many” as in traditional communications. Scientists should first decide on the message they want to convey, and then choose which of the tools facilitates that, she said. She excitedly explained that communications is moving across platforms now—video, audio, text, and graphics: “We’re in the very beginning of all of this” and have not yet begun to use the Web fully yet, she said. O’Brien and others complimented JPL for embracing Twitter, especially in the case of the Mars Phoenix mis- sion, which was the first space mission to “tweet.” JPL’s Veronica McGregor tweeted in the first person as though she was the spacecraft. In a taped interview that O’Brien played for the audience, McGregor said that people who thought they were not interested in following space missions found that they were fascinated if they could get the information in “tiny updates day by day.” O’Brien provided data showing that 44 percent of people polled want more coverage of scientific news and discoveries (Figure 1). He believes social media is the way to provide that coverage. He recommended that scientists not think about how to get on the CBS Evening News, but about how to use social media instead: “All of you should be tweeting” and “sharing the enthusiasm of what you all do.” Kaufman emphasized that the Facebook/Twitter era does not mean the end of books. He believes that people want long as well as short treatments of topics, noting that he just finished writing a book on astrobiology. Seager read a Facebook message she received from a colleague in Canada who wanted to point out that there have been many new forms of communications in the past century and social media are just the latest, and their full implications are not yet known. Kennel offered his opinion that the social media revolution probably “has the same degree of importance as the invention of printing.” He added that “we don’t know . . . how all of that will work out” and NASA and scientists are groping to find out how to use these new ways, but “if we learn to adapt we . . . will be among the groups that . . . survive this change in the way we communicate.” Tips on Connecting with the Public A recurring theme from the communicators was that the space community has to take the public “along for the ride” on space missions and build that feature into missions from the beginning. O’Brien said “NASA is run by engineers, and there are no mission requirements for public affairs.” That has to change, he said, adding, “It cannot be tacked on” at the end, but must be part of the mission from the beginning—a “clean sheet mission requirement.” One question, however, was how to keep the public interested in programs that proceed on an incremental basis with sometimes slow progress. Varying points of view were expressed. Pappalardo wondered, “If we find microbes” and not people on Mars, “will the people care?” Steven Benner, distinguished fellow at the Foundation for Applied Molecular Evolution, however, said that he detects no intolerance on the part of the public for the “struggle” and “incrementalism” inherent in science. Kaufman agreed, but cautioned that there is “danger when incremental change is miniscule,” because with a dwindling cadre of science writers, the media may decide that something is no longer
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61 Summaries of Major Reports FIGURE 1 Coverage of science news and discoveries. SOURCE: K. Purcell, L. Rainie, A. Mitchell, T. Rosenstiel, and K. Olmstead, Understanding the Participatory News Consumer, Pew Research Center’s Internet & American Life Project, Washington, D.C., March 1, 2010. Courtesy of Pew Research Center’s Internet & American Life Project, Washington, D.C. a story worth covering. O’Brien initially said that the media does a poor job of covering incremental stories, but amended that later in the workshop by observing that with the new social media, that may change. Storytelling, narratives, frames, and “people-izing”—making stories more compelling by incorporating the personal stories and enthusiasm of the scientists involved—were all techniques communicators advised would make science communication more effective. Nicholson explained that telling stories is a narrative art, and when they involve human drama “you have a slam dunk almost every time.” Inspiring awe is another method, she added, citing a New York Times article in February 20103 that looked at the most emailed stories and showed they had one thing in common—they all inspired awe, and science can do that, in her view. She also offered that it is important 3J. Tierney, “Will you be e-mailing this column? It’s awesome,” February 8, 2010, The New York Times, available at http://www.nytimes. com/2010/02/09/science/09tier.html.
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62 Space Studies Board Annual Report—2011 to decide how to frame the issue and gave examples from health communications, where different messages can be framed as a gain or a loss. Messages concerning cancer prevention are communicated quite differently if the goal is to get people to use sunscreen versus getting a mammogram. Scheufele expressed a similar theme, saying that frames, narratives, and terminology are critical aspects of relating to the public. As an example, he noted that, at the time of the economic crisis, the story was about “bank bailouts,” but it quickly changed to “rescues” because while people do not want to bail out a bank, they do want to rescue the economy. Some of the communicators advised that messages need to be conveyed in a manner that the public can absorb. Lawler said he was struck at how stark a picture Moore painted about the climate change situation. It is “doom and gloom,” Lawler said, a story to which people do not respond well. Using storytelling would be better, he concluded, citing Roger-Maurice Bonnet’s presentation in Session 5 as an example. Bonnet, executive director of the Inter- national Space Science Institute in Switzerland, used the ISS as an analogy to Earth in order to get across points such as population limits and the need for certain systems—like a thermal protection system (which for Earth is its atmosphere)—to function correctly for the “crew” to survive. Such analogies were cited as an effective communication technique and one often used by scientists. Hammel used a Humpty Dumpty analogy in Session 4 for explaining how the theory of solar system creation has completely changed since she defended her dissertation in 1988. Saying that people connect to a story through narratives, Lawler commended Hammel for her skill at telling the story of the solar system as though it was a “living creature.” Robinson cautioned, however, that analogies can be misleading. He asserted that space is not like the New World or the Wild West, but more like Antarctica, which he found to be difficult and boring when he was there. Scientists and communicators also discussed the need for accuracy in reporting about science, although Kaufman said all science stories in publications like his are likely to have factual errors. The discussion included the fact that scientific interpretations may evolve over time, and discovery by its nature means an ever-changing landscape. As to how to communicate that to the public, Benner stressed that it is not the job of scientists or the media to represent science as anything other than what it is—there are wrong answers or sometimes the need for the reinterpretation of data. Scientists “are not better than the average bear” and should not be represented that way, he said. Kennel suggested that scientists should use the media as intermediaries, but Vernikos strongly disagreed. She said that scientists were excited about what they were doing, and “it’s an energy transfer” when they tell their stories. Bonnet agreed in general, but added that climate scientists did not communicate effectively and could have benefited from taking advantage of professional communicators. Instead, they have opened the door to undue criticisms, in his view. Scheufele remarked that engaging with the interested public is easy, but the question is how to reach the people who are not inclined, for example, to go to science museums. Fifty percent of highly educated Americans go to museums at least once a year, which means that the other 50 percent never go, he pointed out. For people who only went to high school, attendance is less than 10 percent. Science is not an issue the public cares about, he asserted. He also noted that half of the American public does not know how long it takes Earth to move around the Sun. What to Avoid Hammel said astronomers “failed miserably” in explaining to the public why Pluto was demoted from being a planet. She insisted that it was an easy story to tell, and it only takes her 15 minutes to explain it, but astronomers did not think they had to tell it. Lawler agreed, saying that astronomers did not understand that there is “a real emotional tie that people have with planets,” going back to astrology. They are mythical figures and “when you mess with [them], people get upset.” He said that the public felt Pluto was being “knocked off its throne,” and they needed a new story, not just for their old story to be destroyed. Hammel tells that new story, he said. Kennel cited a colleague who believes the public needs to be better educated so that scientists can communicate with them, but thinks any such effort will fail. He wryly noted that the message from the communicators is that there is a new way to communicate now, but many scientists have not mastered the old way. Scheufele listed five ways to ensure a communications failure: • Be reactive instead of proactive; i.e., only start going public after a crisis/event occurs. • Address only issues and ignore values, emotions, etc., that people bring to the table. • Assume that science will ultimately prevail.
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63 Summaries of Major Reports • Assume that new and social media do not matter as much as traditional media. • Assume that communication is an art rather than a science. ASSESSMENTS OF NASA’S PUBLIC AFFAIRS EFFORTS Kaufman offered an unsolicited compliment that NASA public affairs “is far and away the best one I’ve dealt with,” and while there may be problems with how some information in conveyed, he felt the agency deserved a “shout out” because it is doing a better job than most agencies. Later, NASA official Alan Ladwig directly asked for feedback on how NASA is doing. Dexter Cole of the Sci- ence Channel and Lawler both agreed with Kaufman’s assessment that NASA is better than typical federal agencies. However, Lawler also offered a list of improvements NASA could make both at headquarters and the NASA field centers. Separately, Billings observed that NASA’s efforts over the decades have focused on branding and marketing, which she concludes is ineffective. “The aim of marketing is to build public support, and what we all are talking about here is . . . informing people about the work of the science and scientists.” She believes the key to success is public participation, as described above. IMPLICATIONS OF THE NEW COMMUNICATION ERA AND HOW THE NATIONAL ACADEMIES SHOULD RESPOND In his remarks at the conclusion of the workshop, SSB chair Kennel commented that the convergence of com- puting and communications via the Internet and space communications at end of the 20th century has accelerated to this day. That, too, is a product of the science and technology revolution, he said, but because it changes relation- ships between human beings, it has the potential—combined with science—to produce a second enlightenment in the century we are now entering. It is that second enlightenment, created by a partnership between science and communication, that will be critically needed to cope with stark problems of climate change and sustainability, Kennel believes. He feels that in the climate change area, the science community’s “honest attempts to communicate” failed. While a failure of communication in inspirational areas of space science may have consequences such as delaying funding, the failure of communication in the climate area “threatens our entire civilization,” he said. In closing, Kennel voiced a clarion call to the National Academies to adjust to the revolution in communications. [The] final message . . . is for our own National Academy. It is the principal social tool by which the United States translates scientific knowledge into the public and policy arena and therefore it cannot neglect the revolution in communications. We have also heard of how venerable media institutions who did not react to this revolution have failed and we have heard how those who did have continued to prosper in the present world because of the impor- tance . . . of their brand and what they do. I think it is essential for the Academy in the next couple of years—and that is the time scale on which things are occurring—it is necessary for the Academy to adjust to the revolution in communications and the new media. This doesn’t mean getting a few geeks into the back room and providing equipment to people, it means, like everything else, adjusting the social processes by which science is communicated and the people who work on it. I’m not sure I know how that will be done, but I think I can see the need. I am hoping that as we go forth with our study of the potential for human exploration beyond 2020 that we will be able to stimulate—this is an area where this kind of work is critical— and I hope we will be able to stimulate and help the Academy go through this transition. The one thing that is clear, it draws on the talents of many of the smartest people in the United States and it certainly can do it and I’m sure it will.
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64 Space Studies Board Annual Report—2011 5.5 Vision and Voyages for Planetary Science in the Decade 2013-2022 A Report of the SSB Ad Hoc Committee on the Planetary Science Decadal Survey Executive Summary In recent years, planetary science has seen a tremendous growth in new knowledge. Deposits of water ice exist at the Moon’s poles. Discoveries on the surface of Mars point to an early warm, wet climate and perhaps conditions under which life could have emerged. Liquid methane rain falls on Saturn’s moon Titan, creating rivers, lakes, and geologic landscapes with uncanny resemblances to Earth’s. Comets impact Jupiter, producing Earth-size scars in the planet’s atmosphere. Saturn’s poles exhibit bizarre geometric cloud patterns and changes; its rings show processes that may help us understand the nature of planetary accretion. Venus may be volcanically active. Jupiter’s icy moons harbor oceans below their ice shells: conceivably Europa’s ocean could support life. Saturn’s tiny moon Enceladus has enough geothermal energy to drive plumes of ice and vapor from its south pole. Dust from comets shows the nature of the primitive materials from which the planets and life arose. And hundreds of new planets discovered around nearby stars have begun to reveal how the solar system fits into a vast collection of other planetary systems. This report was requested by the National Aeronautics and Space Administration (NASA) and the National Sci - ence Foundation (NSF) to review the status of planetary science in the United States and to develop a comprehensive strategy that will continue these advances in the coming decade. Drawing on extensive interactions with the broad planetary science community, the report presents a decadal program of science and exploration with the potential to yield revolutionary new discoveries. The program will achieve long-standing science goals with a suite of new missions across the solar system. It will provide fundamental new scientific knowledge, engage a broad segment of the planetary science community, and have wide appeal for the general public whose support enables the program. A major accomplishment of the program recommended by the Committee on the Planetary Science Decadal Survey will be taking the first critical steps toward returning carefully selected samples from the surface of Mars. Mars is unique among the planets in having experienced processes comparable to those on Earth during its forma - tion and evolution. Crucially, the martian surface preserves a record of earliest solar system history, on a planet with conditions that may have been similar to those on Earth when life emerged. It is now possible to select a site on Mars from which to collect samples that will address the question of whether the planet was ever an abode of life. The rocks from Mars that we have on Earth in the form of meteorites cannot provide an answer to this question. They are igneous rocks, whereas recent spacecraft observations have shown the occurrence on Mars of chemical sedimentary rocks of aqueous origin, and rocks that have been aqueously altered. It is these materials, none of which are found in meteorites, that provide the opportunity to study aqueous environments, potential prebiotic chemistry, and perhaps, the remains of early martian life. If NASA’s planetary budget is augmented, then the program will also carry out the first in-depth exploration of Jupiter’s icy moon Europa. This moon, with its probable vast subsurface ocean sandwiched between a potentially active silicate interior and a highly dynamic surface ice shell, offers one of the most promising extraterrestrial habitable environments in the solar system and a plausible model for habitable environments outside it. The Jupiter system in which Europa resides hosts an astonishing diversity of phenomena, illuminating fundamental planetary processes. While Voyager and Galileo taught us much about Europa and the Jupiter system, the relatively primitive instrumentation of those missions, and the low volumes of data returned, left many questions unanswered. Major discoveries surely remain to be made. The first step in understanding the potential of the outer solar system as an abode for life is a Europa mission with the goal of confirming the presence of an interior ocean, characterizing the satellite’s ice shell, and enabling understanding of its geologic history. The program will also break new ground deep in the outer solar system. The gas giants Jupiter and Saturn have been studied extensively by the Galileo and Cassini missions, respectively. But Uranus and Neptune represent * NOTE: “Executive Summary” reprinted from Vision and Voyages for Planetary Science in the Decade 2013-2022, The National Academies Press, Washington, D.C., 2011, pp. 1-7.
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65 Summaries of Major Reports a wholly distinct class of planet. While Jupiter and Saturn are made mostly of hydrogen, Uranus and Neptune have much smaller hydrogen envelopes. The bulk composition of these planets is dominated instead by heavier elements: oxygen, carbon, nitrogen, and sulfur are the likely candidates. What little we know about the internal structure and composition of these “ice giant” planets comes from the brief flybys of Voyager 2. The ice giants are thus one of the great remaining unknowns in the solar system, the only class of planet that has never been explored in detail. The proposed program will fill this gap in knowledge by initiating a mission to orbit Uranus and put a probe into the planet’s atmosphere. It is exploration in the truest sense, with the same potential for new discoveries such as those achieved by Galileo at Jupiter and Cassini at Saturn. The program described in this report also vigorously continues NASA’s two programs of competed planetary missions: New Frontiers and Discovery. It includes seven recommended candidate New Frontiers missions from which NASA will select two for flight in the coming decade. These New Frontiers candidates cover a vast sweep of exciting planetary science questions: the surface composition of Venus, the internal structure of the Moon, the composition of the lunar mantle, the nature of Trojan asteroids, the composition of comet nuclei, the geophysics of Jupiter’s volcanic moon Io, and the structure and detailed composition of Saturn’s atmosphere. And continuation of the highly successful Discovery program, which involves regular competitive selections, will provide a steady stream of scientific discoveries from small missions that draw on the full creativity of the science community. Space exploration has become a worldwide venture, and international collaboration has the potential to enrich the program in ways that will benefit all participants. The program therefore relies more strongly than ever before on international participation, presenting many opportunities for collaboration with other nations. Most notably, the ambitious and complex Mars Sample Return campaign is critically dependent on a long-term and enabling collaboration with the European Space Agency (ESA). To assemble this program, the committee used four criteria for selecting and prioritizing missions. The first and most important was science return per dollar. Science return was judged with respect to the key science ques - tions identified by the planetary science community; costs were estimated via a careful and conservative procedure that is described in detail in the body of this report. The second was programmatic balance—striving to achieve an appropriate balance among mission targets across the solar system and an appropriate mix of small, medium, and large missions. The other two were technological readiness and availability of trajectory opportunities within the 2013-2022 time period. To help in developing its recommendations, the committee commissioned technical studies of many candidate missions that were selected for detailed examination on the basis of white papers contributed by the scientific community. Using the four prioritization criteria listed above, the committee chose a subset of the studied mis - sions for independent assessments of technical feasibility, as well as conservative estimates of costs. From these, the committee finalized a set of recommended missions intended to achieve the highest-priority science identified by the community within the budget resources projected to be available. The committee’s program consists of a balanced mix of small Discovery missions, medium-size New Frontiers missions, and large “flagship” missions, enabling both a steady stream of new discoveries and the capability to address major challenges. The mission rec - ommendations assume full funding of all missions that are currently in development, and continuation of missions that are currently in flight, subject to approval obtained through the appropriate review process. SMALL MISSIONS Missions for NASA’s Discovery program lie outside the bounds of a decadal strategic plan, and so this report makes no recommendations on specific Discovery flight missions. The committee emphasizes, however, that the Discovery program has made important and fundamental contributions to planetary exploration and can continue to do so in the coming decade. Because there is still so much compelling science that can be addressed by Discovery missions, the committee recommends continuation of the Discovery program at its current level, adjusted for infla- tion, with a cost cap per mission that is also adjusted for inflation from the current value (i.e., to about $500 mil- lion in fiscal year [FY] 2015). And so that the science community can plan Discovery missions effectively, the committee recommends a regular, predictable, and preferably rapid (≤24-month) cadence for release of Discovery Announcements of Opportunity and for selection of missions. An important small mission that lies outside the Discovery program is the proposed joint ESA-NASA Mars Trace Gas Orbiter that would launch in 2016. The committee supports flight of this mission as long as the currently negotiated division of responsibilities and costs with ESA is preserved.
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66 Space Studies Board Annual Report—2011 MEDIUM MISSIONS The current cost cap for NASA’s competed New Frontiers missions, inflated to FY2015 dollars, is $1.05 billion, including launch vehicle costs. The committee recommends changing the New Frontiers cost cap to $1.0 billion FY2015, excluding launch vehicle costs. This change represents a modest increase in the effective cost cap and will allow a scientifically rich and diverse set of New Frontiers missions to be carried out, and will help protect the science content of the New Frontiers program against increases and volatility in launch vehicle costs. Two New Frontiers missions have been selected by NASA to date, and a third selection was underway while this report was in preparation. The committee recommends that NASA select two additional New Frontiers mis - sions in the decade 2013-2022. These are referred to here as New Frontiers Mission 4 and New Frontiers Mission 5. New Frontiers Mission 4 should be selected from among the following five candidates: • Comet Surface Sample Return, • Lunar South Pole-Aitken Basin Sample Return, • Saturn Probe, • Trojan Tour and Rendezvous, and • Venus In Situ Explorer. No relative priorities are assigned to these five candidates; instead, the selection among them should be made on the basis of competitive peer review. If the third New Frontiers mission selected by NASA addresses the goals of one of these mission candidates, the corresponding candidate should be removed from the above list of five, reducing to four the number from which NASA should make the New Frontiers Mission 4 selection.1 For the New Frontiers Mission 5 selection, the following missions should be added to the list of remaining candidates: • Io Observer, and • Lunar Geophysical Network. Again, no relative priorities are assigned to any of these mission candidates. Tables ES.1 and ES.2 summarize the recommended mission candidates and decision rules for the New Frontiers program. LARGE MISSIONS The highest-priority flagship mission for the decade 2013-2022 is the Mars Astrobiology Explorer-Cacher (MAX-C), which will begin a three-mission NASA-ESA Mars Sample Return campaign extending into the decade beyond 2022. At an estimated cost of $3.5 billion as currently designed, however, MAX-C would take up a dispro - portionate share of NASA’s planetary budget. This high cost results in large part from the goal to deliver two large and capable rovers—a NASA sample-caching rover and the ESA’s ExoMars rover—using a single entry, descent, and landing (EDL) system derived from the Mars Science Laboratory (MSL) EDL system. Accommodation of two such large rovers would require major redesign of the MSL EDL system, with substantial associated cost growth. The committee recommends that NASA fly MAX-C in the decade 2013-2022, but only if the mission can be conducted for a cost to NASA of no more than approximately $2.5 billion FY2015. If a cost of no more than about $2.5 billion FY2015 cannot be verified, the mission (and the subsequent elements of Mars Sample Return) should be deferred until a subsequent decade or canceled. It is likely that a significant reduction in mission scope will be needed to keep the cost of MAX-C below $2.5 billion. To be of benefit to NASA, the Mars exploration partnership with ESA must involve ESA participa - tion in other missions of the Mars Sample Return campaign. The best way to maintain the partnership will be an equitable reduction in scope of both the NASA and the ESA objectives for the joint MAX-C/ExoMars mission, so that both parties still benefit from it. 1On May 25, 2011, following the completion of this report, NASA selected the OSIRIS-REx asteroid sample-return spacecraft as the third New Frontiers mission. Launch is scheduled for 2016.
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67 Summaries of Major Reports TABLE ES.1 Medium-Class Missions—New Frontiers 4 (in alphabetical order) Mission Recommendation Science Objectives Key Challenges Chapter Comet Surface Sample • Acquire and return to Earth for laboratory analysis a macroscopic • Sample acquisition 4 (≥500 cm3) comet nucleus surface sample Return • Mission design • Characterize the surface region sampled • System mass • Preserve sample complex organics Same as 2003 decadal surveya Lunar South Pole-Aitken Not evaluated by decadal 5 Basin Sample Return survey Saturn Probe • Determine noble gas abundances and isotopic ratios of hydrogen, • Entry probe 7 carbon, nitrogen, and oxygen in Saturn’s atmosphere • Payload requirements • Determine the atmospheric structure at the probe descent location growth Trojan Tour and Visit, observe, and characterize multiple Trojan asteroids • System power 4 Rendezvous • System mass Same as 2003 decadal surveya (and amended by 2008 NRC report Venus In Situ Explorer Not evaluated by decadal 5 Opening New Frontiersb) survey NOTE: On May 25, 2011, following the completion of this report, NASA selected the OSIRIS-REx asteroid sample-return spacecraft as the third New Frontiers mission. Launch is scheduled for 2016. a National Research Council, New Frontiers in the Solar System: An Integrated Exploration Strategy, The National Academies Press, Washington, D.C., 2003. b National Research Council, Opening New Frontiers in Space: Choices for the Next New Frontiers Announcement of Opportunity, The National Academies Press, Washington, D.C., 2008. TABLE ES.2 Medium-Class Missions—New Frontiers 5 (in alphabetical order) Mission Recommendation Science Objectives Key Challenges Decision Rules Chapter Comet Surface Sample See Table ES.1 See Table ES.1 Remove if selected 4 Return for NF-4 Io Observer Determine internal structure of Io • Radiation None 8 and mechanisms contributing to • System power Io’s volcanism Lunar Geophysical Enhance knowledge of the lunar • Propulsion None 5 Network interior • Mass • Reliability • Mission operations Same as 2003 decadal surveya Lunar South Pole-Aitken Not evaluated by decadal survey Remove if selected 5 Basin Sample Return for NF-4 Saturn Probe See Table ES.1 See Table ES.1 Remove if selected 7 for NF-4 Trojan Tour and See Table ES.1 See Table ES.1 Remove if selected 4 Rendezvous for NF-4 Same as 2003 decadal surveya (as Venus In Situ Explorer Not evaluated by decadal survey Remove if selected 5 amendedb) for NF-4 NOTE: On May 25, 2011, following the completion of this report, NASA selected the OSIRIS-REx asteroid sample-return spacecraft as the third New Frontiers mission. Launch is scheduled for 2016. a National Research Council, New Frontiers in the Solar System: An Integrated Exploration Strategy, The National Academies Press, Washington, D.C., 2003. b National Research Council, Opening New Frontiers in Space: Choices for the Next New Frontiers Announcement of Opportunity, The National Academies Press, Washington, D.C., 2008.
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68 Space Studies Board Annual Report—2011 The second-highest-priority flagship mission for the decade 2013-2022 is the Jupiter Europa Orbiter (JEO). However, its cost as JEO is currently designed is so high that both a decrease in mission scope and an increase in NASA’s planetary budget are necessary to make it affordable. The projected cost of the mission as currently designed is $4.7 billion FY2015. If JEO were to be funded at this level within the currently projected NASA planetary budget it would lead to an unacceptable programmatic imbalance, eliminating too many other impor- tant missions. Therefore, while the committee recommends JEO as the second-highest-priority flagship mission, close behind MAX-C, it should fly in the decade 2013-2022 only if changes to both the mission and the NASA planetary budget make it affordable without eliminating any other recommended missions. These changes are likely to involve both a reduction in mission scope and a formal budgetary new start for JEO that is accompanied by an increase in the NASA planetary budget. NASA should immediately undertake an effort to find major cost reductions for JEO, with the goal of minimizing the size of the budget increase necessary to enable the mission. The third-highest-priority flagship mission is the Uranus Orbiter and Probe mission. The committee carefully investigated missions to both ice giants, Uranus and Neptune. Although both missions have high scientific merit, the conclusion was that a Uranus mission is favored for the decade 2013-2022 for practical reasons involving avail- able trajectories, flight times, and cost. The Uranus Orbiter and Probe mission should be initiated in the decade 2013-2022 even if both MAX-C and JEO take place. But like those other two missions, it should be subjected to rigorous independent cost verification throughout its development, and should be descoped or canceled if costs grow significantly above the projected cost of $2.7 billion FY2015. Table ES.3 summarizes the recommended large missions and associated decision rules. EXAMPLE FLIGHT PROGRAMS: 2013-2022 Following the priorities and decision rules outlined above, two example programs of solar system exploration can be described for the decade 2013-2022. The recommended program can be conducted assuming a budget increase sufficient to allow a new start for JEO. It includes the following elements (in no particular order): • Discovery program funded at the current level adjusted for inflation, • Mars Trace Gas Orbiter conducted jointly with ESA, TABLE ES.3 Large-Class Missions (in priority order) Mission Recommendation Science Objectives Key Challenges Decision Rules Chapter Mars Astrobiology • Perform in situ science on • Keeping within Mars Science Should be flown 6 Explorer-Cacher descope Mars samples to look for Laboratory design constraints only if it can be evidence of ancient life or • Sample handling, encapsulation, conducted for a cost prebiotic chemistry and containerization to NASA of no more • Collect, document, and • Increased rover traverse speed than approximately package samples for future over Mars Science Laboratory $2.5 billion (FY2015 collection and return to Earth and Mars Exploration Rover dollars) Jupiter Europa Orbiter Explore Europa to investigate its • Radiation Should be flown only 8 descope habitability • Mass if changes to both the • Power mission design and • Instruments the NASA planetary budget make it affordable without eliminating any other recommended missions Uranus Orbiter and • Investigate the interior • Demanding entry probe mission Should be initiated 7 Probe (no solar-electric structure, atmosphere, and • Long life (15.4 years) for orbiter even if both MAX-C propulsion stage) composition of Uranus • High magnetic cleanliness for and JEO take place • Observe the Uranus satellite orbiter and ring systems • System mass and power
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69 Summaries of Major Reports • New Frontiers Missions 4 and 5, • MAX-C (descoped to $2.5 billion), • Jupiter Europa Orbiter (descoped), and • Uranus Orbiter and Probe. The cost-constrained program can be conducted assuming the currently projected NASA planetary budget (see Appendix E). It includes the following elements (in no particular order): • Discovery program funded at the current level adjusted for inflation, • Mars Trace Gas Orbiter conducted jointly with ESA, • New Frontiers Mission 4 and 5, • MAX-C (descoped to $2.5 billion), and • Uranus Orbiter and Probe. Plausible circumstances could improve the budget picture presented above. If this happened, the additions to the recommended program should be, in priority order: 1. An increase in funding for the Discovery program, 2. Another New Frontiers mission, and 3. Either the Enceladus Orbiter mission or the Venus Climate Mission. It is also possible that the budget picture could be less favorable than the committee has assumed. If cuts to the program are necessary, the first approach should be to descope or delay flagship missions. Changes to the New Frontiers or Discovery programs should be considered only if adjustments to flagship missions cannot solve the problem. And high priority should be placed on preserving funding for research and analysis programs and for technology development. Looking ahead to possible missions in the decade beyond 2022, it is important to make significant near-term technology investments now in the Mars Sample Return Lander, Mars Sample Return Orbiter, Titan Saturn System Mission, and Neptune System Orbiter and Probe. NASA-FUNDED SUPPORTING RESEARCH AND TECHNOLOGY DEVELOPMENT NASA’s planetary research and analysis programs are heavily oversubscribed. Consistent with the mission recommendations and costs presented above, the committee recommends that NASA increase the research and analysis budget for planetary science by 5 percent above the total finally approved FY2011 expenditures in the first year of the coming decade, and increase the budget by 1.5 percent above the inflation level for each successive year of the decade. Also, the future of planetary science depends on a well-conceived, robust, stable technology investment program. The committee unequivocally recommends that a substantial program of planetary exploration technology development should be reconstituted and carefully protected against all incursions that would deplete its resources. This program should be consistently funded at approximately 6 to 8 percent of the total NASA Planetary Science Division budget. NSF-FUNDED RESEARCH AND INFRASTRUCTURE The National Science Foundation supports nearly all areas of planetary science except space missions, which it supports indirectly through laboratory research and archived data. NSF grants and support for field activities are an important source of support for planetary science in the United States and should continue. NSF is also the largest federal funding agency for ground-based astronomy in the United States. The ground-based observational facilities supported wholly or in part by NSF are essential to planetary astronomical observations, both in support of active space missions and in studies independent of (or as follow-up to) such missions. Their continued support is critical to the advancement of planetary science.
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70 Space Studies Board Annual Report—2011 One of the future NSF-funded facilities most important to planetary science is the Large Synoptic Survey Telescope (LSST). The committee encourages the timely completion of LSST and stresses the importance of its contributions to planetary science once telescope operations begin. Finally, the committee recommends expan - sion of NSF funding for the support of planetary science in existing laboratories, and the establishment of new laboratories as needs develop.