Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
4 Leadership for Current and Future Space Missions This chapter evaluates the success of the NASA Astrobiology Institute (NAI) in achieving its stated goal of pro- viding scientific and technical leadership on astrobiology investigations for current and future space missions. NAI CONTRIBUTIONS As pointed out in Chapter 1, the field of astrobiology provides the intellectual and scientific foundation for much if not all of NASAâs current robotic solar system exploration missions1 and many of its astrophysical activities relating to the search for and characterization of extrasolar planets (exoplanets). 2 Understanding how life arose on Earth and how it evolved helps to define the scientific rationale for recognizing life elsewhere in the solar system and beyond. These questions are also central to many of the science goals enunciated in the Vision for Space Exploration.3 The current NASA strategy of âfollow the waterâ for exploring Mars4 and, by extension, the rest of the solar system and beyond forms the basis for future missions that will focus on specific astrobiology themes. The pres- ence of past and recent-present water on Mars has almost certainly been established (e.g., by the Mars Exploration Rovers and the Mars Reconnaissance Orbiter),5 and the existence of subsurface ice is expected to be confirmed with the recently launched Mars Phoenix mission. As a result, the NAI has a unique opportunity to begin prepar- ing for missions that will critically assess the question of life beyond Earth. Astrobiology also has been and will likely remain the major driver in the exploration of the outer solar system, influencing planning for missions to the Galilean satellites of Jupiter and to Saturnâs moons, Titan and Enceladus. Astrobiology also has influenced and will continue to influence NASAâs astrophysical investigations, such as those that use the Hubble Space Telescope, the Spitzer Space Telescope, and, eventually, the Kepler mission and the James Webb Space Telescope in the search for and characterization of Earth-sized planets orbiting other stars. It would be appropriate for the astrobiology community to help define a mission that highlights the search for life in the universe, a compelling question that provides intellectual connections to the search for Earth-like planets and investigations of their potential habitability. Although the NASA Astrobiology Institute has been in existence for almost 10 years, as an institution it has not played a dramatically significant role in NASAâs current and future strategy to explore the solar system and beyond. This does not mean that the NAI and, in particular, members of NAI teams have not played a central role in determining NASAâs plans for current and future missions. The NAI regards the following particular activities as its principal contributions to NASAâs flight program: 42
LEADERSHIP FOR CURRENT AND FUTURE SPACE MISSIONS 43 â¢ Mars landing sites and exploration strategy. The NAI Mars Focus Group, initially chaired by Jack Farmer (principal investigator of the NAI team at Arizona State University), provided key recommendations on Mars landing sites. Subsequently, the NAI has contributed several chairs to NASAâs Mars Exploration Program Analysis Group (MEPAG), the group developing Mars exploration strategy. In addition to Farmer, NAI members who have chaired MEPAG include Ronald Greeley (Arizona State University team), Bruce Jakosky (PI of the NAI team at the University of Colorado), and Jack Mustard (Marine Biological Laboratory team), providing continuing input to NASA mission planners. See Box 4.1 for more information. â¢ Future Mars missions. NAI member Mark Allen (Jet Propulsion Laboratory) developed a proposed Mars Scout, the Mars Volcanic Emission and Life (MARVEL) mission to measure atmospheric composition and loss mechanisms, that has led to the selection of these objectives for the Mars Science Orbiter proposed for launch in 2013. The NAI also provided a context for development of the current Mars Atmosphere and Volatile Evolution BOX 4.1 MARS LANDING SITES AND EXPLORATION STRATEGY The many recent discoveries about the past and present habitability of Mars are linked to an astrobiology-inspired strategy for Mars exploration called âfollow the water.â The NAI played a key role in recommendations for landing sites for the Mars Exploration Rovers (MERs), which were presented by the focus group chair (Jack Farmer, principal investigator [PI] of the NAI team at Arizona State University) at community-wide landing-site workshops. Based on inputs from these workshops, the MER Landing Sites Steering Committee developed a short list of approximately 10 sites, half of them on the NAI list of recom- mendations. Both of the final landing site selections (Opportunityâs landing site on Meridiani Planum and Spiritâs landing site in Gusev Crater) had been given a high priority for astrobiology by the NAI Mars Focus Group. On the question of landing site selection, interactions between the NAI and NASAâs Mars Exploration Program Analysis Group (MEPAG) were promoted through several NAI-sponsored videoconferences orga- nized by the chair of the Mars Focus Group. So effective were these contributions that when Jack Farmer was appointed to lead MEPAG, much of the NAI focus group activity simply merged with the NASA-wide advisory system. Another indication of NAI influence can be drawn from the fact that roughly 70 percent of the au- thors of recent MEPAG reports are members of past or present NAI teams. These individuals include the following: â¢ Ames Research Center teamâDavid Des Marais (PI), Christopher McKay, and Allan Treiman; â¢ Arizona State University teamâPhillip Christensen, James Elser, Jack Farmer (PI), Ronald Greeley, and Ferran Garcia-Pichel; â¢ Carnegie Institution of Washington teamâNora Noffke and Andrew Steele; â¢ Goddard Space Flight Center teamâPaul Mahaffy; â¢ Jet Propulsion Laboratory teamâKenneth Nealson (PI); â¢ Johnson Space Center teamâThomas Kieft; â¢ Marine Biological Laboratory teamâJames Head and Mitchell Sogin (PI); â¢ Massachusetts Institute of Technology teamâRoger Summons (PI); â¢ Pennsylvania State University teamâChristopher House; â¢ SETI Institute teamâRocco Mancinelli (PI); â¢ University of Arizona teamâJohn Baross; â¢ University of Colorado teamâBruce Jakosky (PI) and Stephen Mojzsis; â¢ University of Hawaii teamâJeffrey Taylor; and â¢ University of Washington teamâJohn Baross and Jody Deming.
44 ASSESSMENT OF THE NASA ASTROBIOLOGY INSTITUTE BOX 4.2 FUTURE MARS MISSIONS Mark Allen (Jet Propulsion Laboratory) was stimulated by his membership in the NAI to adapt tech- niques for studying terrestrial photochemistry to the detection of trace gases in the martian atmosphere, and he was first author of the report âIs Mars Alive?â from the NAI Virtual Workshop on Methane on Mars held in March 2005.1 Allenâs Mars Scout (MARVEL) proposal was not selected for flight, but his instru- ment approach combined with excitement about the possible detection of methane on Mars (NAI Goddard Space Flight Center team and others) led to the selection by NASA of a trace gas science payload for the proposed 2013 Mars Science Orbiter. The MAVEN Mars Scout candidate mission (Bruce Jakosky, PI of the NAI team at the University of Colorado) also emerged from the interdisciplinary environment fostered by the NAI. ââ 1M. Allen, B. Sherwood Lollar, B. Runnegar, D.Z. Oehlar, J.R. Lyons, C.E. Manning, and M.E. Summers, âIs Mars Alive?â EOS 87: 433-448, 2006. (MAVEN) Scout proposal led by Bruce Jakosky, the PI of the NAI team at the University of Colorado. See Box 4.2 for more information. â¢ Astrobiology in the NRCâs solar system exploration decadal survey report. Recognizing the increasing importance of astrobiology in planetary science, the NAI provided formal input to the NRCâs solar system explo- ration decadal survey, including a rationale for recognizing astrobiology as a central component, ways in which astrobiology interacts with the rest of solar system exploration, and a ranking of key missions. See Box 4.3 for more information. BOX 4.3 ASTROBIOLOGY IN THE NRCâS SOLAR SYSTEM EXPLORATION DECADAL SURVEY REPORT At the request of the National Research Councilâs (NRCâs) Committee on the Origins and Evolution of Life, the NAI provided input on astrobiology to the NRCâs solar system exploration (SSE) decadal survey committee. Astrobiologists discussed the role of astrobiology in solar system exploration and the nature of flight missions that would contribute simultaneously to addressing the goals and objectives of solar system exploration and astrobiology. The SSE decadal survey committee took the input to heart and, in its report, described the importance of astrobiology as one of the fundamental underpinnings of solar system exploration.1 This embracing of astrobiology was consistent with the increased visibility that astrobiology was receiving as the intellectual centerpiece of the planetary exploration program. As put forward by the NAI, the highest-priority missions lined up remarkably well with those missions that were considered as having the highest priority for solar system exploration independent of the role of astrobiology. This corre- spondence can be seen as evidence of the numerous ways in which astrobiology science goals mesh with non-astrobiology goals designed to elucidate the formation and evolution of our planetary system. Thus the list of priority missions recommended by the NRC agreed closely with those put forward for astrobiology by the NAI. ââ 1National Research Council, New Frontiers in the Solar System: An Integrated Exploration Strategy, The National Academies Press, Washington, D.C., 2003.
LEADERSHIP FOR CURRENT AND FUTURE SPACE MISSIONS 45 BOX 4.4 PALE BLUE DOT From its inception, the NAI has recognized the importance of astronomical biosignatures, evidence for life that could be detected on exoplanets by instruments such as NASAâs proposed Terrestrial Planet Finder mission. Since for the foreseeable future such terrestrial exoplanets will only be seen as single pixels (i.e., pale blue dots), biosignatures must be global, detectable in the spectra of such planets. The challenge is highly interdisciplinary, involving planetary science and geoscience (to understand the range of expected surfaces and atmospheres of terrestrial exoplanets), biology (to understand the influence of microbes and possibly other life forms on the composition of the atmosphere and the reflectance of the surface), and astronomy (to determine which spectral regions might carry spectral biosignatures and to design instru- ments that could detect them). It is desired, of course, to distinguish planets that are habitable (capable of supporting life) from those where life exists and has imposed a detectable biosignature on the spectrum. Over the past decade, the NAI has cosponsored three community-wide âPale Blue Dotâ conferences in which NAI PIs David Des Marais (Ames Research Center) and Victoria Meadows (California Institute of Technology, now at the University of Washington) played leading roles as organizers. Meadows leads the NAIâs Virtual Planetary Laboratory, which has focused on a broadly based theoretical effort to understand the co-evolution of terrestrial-type planets and their biospheres. â¢ Pale blue dot. Three NAI-sponsored conferences have focused on defining astronomical biosignatures, examining the coupling of biotic activity, planetary environmental conditions, and the parent star. The work of the NAIâs Virtual Planetary Laboratory has provided much of the scientific underpinning for these conferences. See Box 4.4 for more information. â¢ M Stars and habitability. The NAI team at the SETI Institute led a workshop as part of a multidisciplinary re-examination of the likely habitability of M-star planets. The positive outcome of this work has more than doubled the range of potential target planets that might support life. See Box 4.5 for more information. â¢ Astrobiology and the James Webb Space Telescope. The NAI Astronomy Focus Group made recommen- dations to NASA for astrobiology programs that could be accomplished with the James Webb Space Telescope, which will be a powerful asset for studying the processes by which planets form and acquire essential ingredients for life, and for investigating faint comets and exoplanets. See Box 4.6 for more information. BOX 4.5 M STARS AND HABITABILITY In the summer of 2006, Rocco Mancinelli (the principal investigator of the NAI team at the SETI Institute) co-organized and hosted a workshop to examine the prospect that planets orbiting dwarf M stars are habitable for either microscopic or complex life. Some 30 scientists from 19 institutions in the United States and the United Kingdom participated, with 13 of the participants representing 6 other NAI teams. A paper summarizing some of the material presented at the workshop, together with other results relating to the habitability of M stars, was published in the February 2007 issue of Astrobiology.1 The consensus of these activities was that there is no reason to preclude the possibility of life on a planet orbiting a dwarf M star. Since the number of M dwarfs is approximately 10 times greater than the number of Sun-like G stars, this conclusion will have important implications for searches for life. ââ 1J. Scalo et al., âM Stars as Targets for Terrestrial Exoplanet Searches and Biosignature Detection,â Astrobiology 7: 85-166, 2007; and âSpecial Collection of Papers: M Star Habitability,â Astrobiology 7: 27-274, 2007.
46 ASSESSMENT OF THE NASA ASTROBIOLOGY INSTITUTE BOX 4.6 ASTROBIOLOGY AND THE JAMES WEBB SPACE TELESCOPE The NAI formed the Astronomy Focus Group in 2003. Its first task was to consider the role of the James Webb Space Telescope (JWST) in contributing to astrobiology. The focus group was chaired by Sara Seager (Carnegie Institution of Washington, now at the Massachusetts Institute of Technology) and Jonathan Lunine (University of Arizona). A workshop held by the group led to recommendations for realizing many ânascent capabilitiesâ of JWST for astrobiology.1 These recommendations included developing comet-track- ing software, allowing high-cadence observations of bright sources, improving stray-light rejection and the stability of the point-spread function to allow observations of faint planets near bright stars, and enhancing coronagraphic capability with careful control of scattered light. Many of the recommendations were imple- mented, leading to an expectation of greatly improved astrobiological capability for this mission. ââ 1S. Seager and J.I. Lunine (eds.), âAstrobiology and JWST: A Report to NASA Recommending Additional or Optimi- zation of the James Webb Space Telescope Capabilities to Maximize Astrobiology Science Return,â unpublished white paper available at http://www.dtm.ciw.edu/seager/NAIAFG/JWST.pdf. â¢ Lunar astrobiology. In response to the plan enunciated by the Vision for Space Exploration to return astronauts to the Moon, the NAI organized a workshop and developed a white paper on lunar astrobiology. Rec- ommendations included using the Moon to understand the environment on ancient Earth and making integrated observations of Earth from the Moon to calibrate potential astronomical biosignatures for exoplanets. Many of these recommendations were subsequently included in the NRC report Scientific Context for Exploration of the Moon.6 See Box 4.7 for more information. BOX 4.7 LUNAR ASTROBIOLOGY In July 2004 the NAI prepared a white paper for NASA headquarters titled âAstrobiology Science Goals and Lunar Explorationâ with Bruce Jakosky (principal investigator [PI] of the NAI team at University of Colorado) as primary author.1 The white paper noted that the Moon preserves unique information about the habitability of the Earth-Moon system, particularly from early eras for which Earthâs record is largely missing. The NAI suggested study of two specific issues concerning the early solar system: the history of impacts and the history of exposure to radiation. The Moon is expected to provide the data for a quantita- tive investigation of these issues. Each of these problems can be addressed in a step-wise manner by a NASA lunar science program that includes orbital imaging and remote sensing, in situ analysis from landed spacecraft, robotic sample-return missions, and human exploration missions. More recent discussion within the NAI (led by Neville Wolff, PI of the NAI team at the University of Arizona) has identified an additional opportunity, using the Moon as a platform for low-spatial-resolution (single-pixel) observations of the whole Earth, as a function of phase, to demonstrate and calibrate approaches to the âpale blue dotâ challenge of detecting biosignatures on exoplanets. ââ 1B.M. Jakosky, A. Anbar, G.J. Taylor, and P. Lucey, âAstrobiology Science Goals and Lunar Exploration: NASA Astrobiology Institute White Paper,â unpublished white paper available at http://nai.arc.nasa.gov/library/downloads/ lunar_astrobiology.pdf.
LEADERSHIP FOR CURRENT AND FUTURE SPACE MISSIONS 47 The main conclusion to be drawn from this list is that the NAIâs influence on missions has been indirect and has come principally through the actions of individual scientists affiliated with NAI teams. This is probably the most appropriate vehicle for the NAIâs involvement in NASAâs flight program. The committee agrees with the NRCâs 2003 review of NASAâs Astrobiology program that considered the appropriateness of the NAIâs involve- ment in the development or selection of missions and cautioned NASA âagainst attempting to force the NASA Astrobiology Institute . . . into an artificially focused role of trying to design specific âastrobiology missionsâ.â 7 While the 2003 report encouraged individual NAI team members to propose instrument or entire PI-class mis- sions (e.g., Discovery, Mars Scout, or Explorers), the direct involvement of the NAI as an entity was worrisome because it might appear to bias NASAâs well-understood and time-tested peer-review selection process in favor of a small group of NAI insiders. To fully integrate astrobiology into NASAâs strategy for future missions while precluding the NAI from becom- ing too directly involved in their design or selection, the astrobiology community itself (both NAI members and others) must take responsibility for providing scientific and technical leadership on astrobiology investigations for current and future space missions. Therefore, the role of the NAI is to provide the astrobiology community with the tools necessary to take that leadership role. The NAI performs this function through its support of focus groups (i.e., forums where like-minded astrobi- ologists can discuss issues of mutual interest) that address a variety of specific issues associated with flight mis- sions. Particularly notable are the activities of the focus groups concerned with defining strategies for exploring Mars (1999-2003), Europa (2001 to present), astro/cometary materials (2002-2003), and Titan (2003-present, now called the Icy Worlds focus group). The recent reinvigoration of the NAIâs Mars focus group has already made significant contributions to NASAâs Mars Next-Decade group, which is looking at Mars exploration activities beyond the Mars Science Laboratory program. This is an important step toward establishing a more strategic role for astrobiology in future mission planning. RELATIONSHIP TO OTHER ASTROBIOLOGY PROGRAMS There are several programs complementary to the NAI that are supported by the Science Mission Directorate: the Exobiology and Evolutionary Biology grants programs, the Astrobiology Science and Technology Instrument Development (ASTID) program, and the Astrobiology Science and Technology for Exploring Planets (ASTEP) program. These programs each contribute to NASA planning of flight opportunities, and there is good synergy among the various activities. The NAI and the scientists it supports have contributed directly to the National Research Councilâs decadal survey process. Indeed, as is mentioned in Chapter 1, the astronomy and astrophysics decadal survey and the solar system exploration decadal survey include language highly supportive of the scientific goals of astrobiology. Both surveys and at least one more recent NRC report8 point to the close alignment between specific missions of interest to astronomers (e.g., the search for and characterization of exoplanets) and planetary scientists (e.g., the exploration of Mars, Europa, and Titan) and the activities of direct interest to astrobiologists. So, although the Astrobiology program has no missions entirely of its own, it has proxy ownership of missions belonging to other NASA science programs. Indeed, this alignment of interest between astrobiology and other NASA programs, for which NAI rightfully deserves credit, represents a very effective leveraging of astrobiology funds. 9,10 In keeping with the close alignment between subjects of interest to astrobiology and the planetary science community, NAI members regularly serve on science definition teams for missions to Mars and Europa and are members of the science teams of the Mars Exploration Rovers, the Mars Reconnaissance Orbiter, the Mars Science Laboratory, and the Mars Phoenix missions. BALANCE OF NAI ACTIVITIES The focus groups provide an appropriate mechanism for the NAI and, more importantly, the wider astrobiol- ogy community to play an important strategic role in defining NASAâs future missions. Participation in the focus groups is open to all interested parties and not just the scientists supported by the NAI or by other NASA programs.
48 ASSESSMENT OF THE NASA ASTROBIOLOGY INSTITUTE A model for how the focus groups could play an even more strategic role in the future is given by MEPAG and its emulators,11 the Outer Planets Analysis Group (OPAG),12 the Venus Exploration Analysis Group (VEXAG),13 and the Lunar Exploration Analysis Group (LEAG).14 Through the drafting and promotion of timely white papers and, more importantly, the systematic documentation of key scientific goals and objectives, and by defining investiga- tions and priorities for their respective areas of interest,15 the âAGsâ have played an important role in NASAâs strategic planning exercises. Moreover, such groups provide a forum at which scientists can interact with their engineering counterparts and form the partnerships essential to the design of future spacecraft missions. The NAI could further promote the astrobiology communityâs contribution to planned and future missions by building on the present missions that include some astrobiology goals, for example the Mars Science Laboratory (MSL), scheduled for launch in September 2009. One of the key questions to be addressed by MSL is the critical astrobiology objective to investigate the past and present habitability of Mars (i.e., the planetâs potential for sup- porting life of any kind). To perform this task the MSL payload includes several instruments that will assess the biological potential of several special regions on Mars, characterize the geology and geochemistry of those regions, investigate the planetary processes that influence habitability, and measure the surface radiation environment. The NAI should actively promote one or more focus groups to build on MSLâs habitability strategy by helping to define the scientific requirements and goals for a follow-up missionâsuch as the proposed Astrobiology Field Laboratoryâthat has the principal goal of determining if life has ever developed on Mars. A similar approach can be adopted for other potential missions that will contribute to achieving the scientific goals outlined in the Astrobiology Roadmap. RECOMMENDATIONS FOR FUTURE NAI ACTIVITIES With respect to the goal of providing scientific and technical leadership on astrobiology investigations for current and future space missions, the committee finds that the NAI has: â¢ Encouraged astrobiologists to provide needed recommendations and expertise to NASA for mission planning. â¢ Promoted the participation of astrobiologists in the science teams for current and future missions. This has been an effective mechanism for involving life scientists and others in NASA programs. â¢ Organized activities, such as focus groups, that have strongly influenced NASA missions. There are many factors that help determine a NASA mission, but this is an important way to ensure that the science is as relevant as possible. â¢ Identified astrobiology questions that underpin most of NASAâs current flight programs. The potential discovery of the existence of life on worlds other than Earth is certainly one of the most important reasons for many NASA missions. But it must be remembered that the goals of astrobiology go beyond the search for life and encompass a far richer and broader set of questions relating to the origin and co-evolution of life and habitable environments. This breadth of goals gives astrobiology great resilience in the face of short-term programmatic changes. The NRCâs 2003 review of NASAâs Astrobiology program recommended that âan important operational goal of astrobiology is to inform NASA missions with respect to the techniques and targets for the search for life else- where, and the search for clues to the steps leading to the origin of life on Earth.â 16 The committee endorses this recommendation and suggests that the most critical function of the NAI is to remain central to NASA spaceflight programs. Recommendation: Because its most critical function is to ensure that its research activities clearly con- tribute to NASAâs current and future spaceflight activities, the NAI should be more proactive in identifying future astrobiology missions. In addition, the NAI should actively encourage a partnership between astro- biologists and their engineering counterparts to help define future NASA missions. Although the committee
LEADERSHIP FOR CURRENT AND FUTURE SPACE MISSIONS 49 has not, in general, prioritized its recommendations, it believes that this one is of the highest importance. The committee suggests the following actions to implement this recommendation: â¢ The NAI focus groups have suffered from a lack of stable leadership and sustained activity, despite their demonstrated value as open community forums for the exchange of ideas and as venues whereby the NAI can take a leadership role within the larger space science community. The creation and continued support of focus groups should be strongly promoted and their performance critically evaluated at periodic intervals by NAI Central and the NAI Executive Council in strategic areas, especially those related to NASA missions and the scientific goals outlined in the Astrobiology Roadmap, to make sure that they remain responsive to NASA needs. â¢ Securing a tie to NASA flight programs is critical to the future of the field of astrobiology because the public is very interested in following NASA missions, and making the latest measurements and information widely available in a timely fashion allows the public to share in the discoveries and perhaps help determine the future directions NASA should pursue. In this context, the NAI should continue to promote a vigorous outreach program. â¢ The NAI should provide scientific recommendations in areas of mission strategy to NASA. It is critical that the exploration of the Moon and of Mars have a very firm scientific justification, and the astrobiology community, through the NAI, should take the lead in providing roadmaps outlining scientific goals, objectives, investigations, and priorities for these endeavors. As progress is made in addressing the key questions in astrobiology, important information such as improvements in scientific understanding of how life evolved on Earth should be factored into specific strategies for how to explore other planets. A continuous updating of the state-of-the-art knowledge founded on ground-based results, improved theories, and the latest astrobiology thinking as it relates to the details of planned missions would help ensure that NASA missions are as productive as possible. The focus groups are an appropriate mechanism for undertaking such activities. â¢ The NAI director has an important role to play as the de facto point of contact between the astrobiology community and relevant NASA flight programs. As such, the director should consult with the teams responsible for current and future flight programs and help to identify the most appropriate sources of astrobiological advice for their respective activities. Similarly, the NAI director should actively encourage NAI and non-NAI astrobiolo- gists to serve on mission planning activities, focus groups, and mission science teams. Recommendation: In selecting new nodes, the NAI should give more weight to the potential contribution of the proposed research to future NASA missions. Specifically, in the evaluation of proposals for new nodes, the NAI should require the proposed research program to demonstrate relevance to potential NASA missions that, if successful, would provide insight that can be translated into enhanced mission activities. NOTES â 1. National Research Council, New Frontiers in the Solar System: An Integrated Exploration Strategy, The National Academies Press, Washington, D.C., 2003, pp. 157-158. â 2. National Research Council, Astronomy and Astrophysics in the New Millennium, National Academy Press, Washington, D.C., 2001, pp. 157-158. â 3. National Aeronautics and Space Administration, The Vision for Space Exploration, NP-2004-01-334-HQ, NASA, Washington, D.C., 2004, pp. 4-13. â 4. See, for example, D.J. McCleese and the Mars Advanced Planning Group 2006, Robotic Mars Exploration Strategy 2007-2016, JPL- 400-1276, Jet Propulsion Laboratory, Pasadena, California, 2006, pp. 7-9. Also see, D.W. Beaty, M.A. Meyer, and the Mars Advanced Planning Group 2006, 2006 Update to Robotic Mars Exploration Strategy 2007-2016, unpublished white paper, posted November 2006 by the Mars Exploration Program Analysis Group at http://mepag.jpl.nasa.gov/reports/index.html. â 5. See, for example, National Research Council, Assessment of NASAâs Mars Architecture 2007-2016, The National Academies Press, Washington, D.C., 2006, pp. 11-12. â 6. National Research Council, The Scientific Context for Exploration of the Moon, The National Academies Press, Washington, D.C., 2007.
50 ASSESSMENT OF THE NASA ASTROBIOLOGY INSTITUTE â 7. National Research Council, Life in the Universe: An Assessment of U.S. and International Programs in Astrobiology, The National Academies Press, Washington, D.C., 2003, pp. 5 and 28. â 8. National Research Program, An Assessment of Balance in NASAâs Science Programs, The National Academies Press, Washington, D.C., 2006, pp. 20-21. â 9. National Research Council, Astronomy and Astrophysics in the New Millennium, National Academy Press, Washington, D.C., 2001. 10. National Research Council, New Frontiers in the Solar System: An Integrated Exploration Strategy, The National Academies Press, Washington, D.C., 2003. 11. For more information about MEPAG see http://mepag.jpl.nasa.gov/. 12. For more information about OPAG see http://www.lpi.usra.edu/opag/. 13. For more information about VEXAG see http://www.lpi.usra.edu/vexag/. 14. For more information about LEAG see http://www.lpi.usra.edu/leag/. 15. For more information about, for example, MEPAGâs Mars Scientific Goals, Objectives, Investigations, and Priorities document, see http://mepag.jpl.nasa.gov/reports/MEPAG%20Goals_2-10-2006.pdf. 16. National Research Council, Life in the Universe: An Assessment of U.S. and International Programs in Astrobiology, The National Academies Press, Washington, D.C., 2003, pp. 2 and 13.