The Role of Small Missions in Planetary and Lunar Exploration (1995) / Chapter Skim
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2 The Small-Mission Concept
2 The Small-Mission Concept
Pages 13-21
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From page 13... ...
EXECUTIVE SUMMARY According to a 1986 report by the Committee on Space Astronomy and CHAPTER 1 Astrophysics, "the Explorer program has established an outstanding record of CHAPTER 2 CHAPTER 3 scientific accomplishments in a variety of space science fields including CHAPTER 4 astronomy and astrophysics, space plasma physics, and solar physics" and CHAPTER 5 "there is no doubt that the Explorer program has resulted in outstanding scientific APPENDIX discoveries and continues to contribute in a vital way to the progress of space research."1 These conclusions reflect those of an earlier assessment by the Committee on Solar and Space Physics, which commented that "science ideas of high priority can be addressed with Explorers" and that "a high frequency of flight opportunities is warranted."2 Moreover, the record of the past and plans for the near future testify to the high quality of innovative science that is achieved by peer-selected Explorer missions. The primary complaint from these communities is that flights are much too scarce compared with the numerous scientific problems that can be addressed by low-cost missions.
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From page 14... ...
Nevertheless, the completed Clementine mission and the development of the NEAR and Mars Pathfinder missions provide some calibration as to the level of the returned science that might be expected from small planetary missions. Examples of typical programs that may be possible under the general heading of small planetary science missions include Earth-orbital telescopes, flyby or orbital missions, and in situ sampling probes.
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From page 15... ...
For example, will atmospheric sampling missions be restricted to inner solar system bodies, and are in situ measurements of solid surfaces possible to accomplish at' all within the Discovery constraints? Although it is clearly harder to fit sampling missions and flights to the outer solar system into Discovery's $150 million cost envelope, innovative ways to achieve these objectives may be attainable.
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From page 16... ...
Composition can be well constrained by remote sensing, but sample analysis whether in situ or by returned materials-may be required for definitive results. Cometary missions ranging in complexity from coma analysis, through penetrators and coma sample return, and ultimately to surface sample return may be proposed or attempted as small missions; some of these may turn out to be too expensive to be executed as small missions.
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From page 17... ...
Accordingly, an individual small mission, with its strongly focused science objectives, can address only part of what the Integrated Strategy calls for at these two planets. The Integrated Strategy set as its fourth priority the detection and study of circumstellar disks and extrasolar planets.
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From page 18... ...
Before listing desirable attributes, it is essential to stress that a reduction in mission scale must not be taken to imply any lessening in the quality of the science that must be produced: any space program should aim for nothing less than addressing the most important scientific objectives and use of the most capable instrumentation available, with missions being selected by fully open competition. The reason that care must be taken to ensure that only the highest-quality science is accepted is that, despite being less costly than most previous planetary spacecraft, Discovery missions still have significant costs so that, in a constrained budget, only very few will be flown.
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From page 19... ...
The relatively brief development time of small planetary spacecraft, as in the proposed Discovery program, makes it feasible to address targets of opportunity, whereas a traditional mission lacks the requisite flexibility. For file:///C|/SSB_old_web/smlch2.html (7 of 10)
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From page 20... ...
Such a decentralized mission organization, located within an educational institution, will lend itself to even more wide-spread outreach, extending beyond the university to K-12 education. Finally, teaming among universities, industrial organizations, and NASA centers, as emphasized within the proposed Discovery program, will be useful in stimulating constructive interactions among those organizations.
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From page 21... ...
3. Board on Atmospheric Sciences and Climate and Space Studies Board, National Research Council, A Space Physics Paradox, National Academy Press, Washington, D.C., 1994.
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