Assessment of Mission Size Trade-offs for NASA's Earth and Space Science Missions (2000) / Chapter Skim
Currently Skimming:
Appendix E Material Provided by Space Studies Board Discipline Committees
Appendix E Material Provided by Space Studies Board Discipline Committees
Pages 71-85
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 71... ...
EARTH SCIENCE Arguments for a Portfolio of Mission Sizes There are powerful arguments for having a broad portfolio of mission sizes to achieve near-term (10 years) and far-term (10 to 20 years)
|
From page 72... ...
accommodation adequate to support large instruments. Increased science requirements or the need for more comprehensive data sets lead to significant growth in several instruments central to Earth science applications.2 This growth is driven by increases sometimes by large factors in the required spatial resolution, number of spectral bands, and signal amplitude resolution (bits per sample)
|
From page 73... ...
/NPOESS and NASAIEarth Science Enterprise capabilities for climate research. Among the conclusions, the Committee on Earth Studies notes that climate studies require long-term measurements, revision and independent validation of the algorithms, ability to reprocess older data, and good characterization and calibration of instruments.
|
From page 74... ...
Total mission costs are about twice those billed to NASA, thanks to major foreign contributions. GRACE would not be possible without extensive prior developments, including a large science base and an existing spacecraft design, Challenging Minisatellite Payload (CHAMP)
|
From page 75... ...
PLANNED ESSP-2 Gravity field mapping (two spacecraft (GRACE) constellation)
|
From page 76... ...
aNA, not available. Criteria for Evaluating the Mission Mix Previous Space Studies Board reports identified several criteria that can be used for evaluating the balance of missions in the Earth science portfolio.l6 In addition to being assessed on their individual scientific meet, missions are assessed based on the extent to which they do the following: Address the high-pnonty scientific goals;l7 Serve the needs of the U.S.
|
From page 77... ...
believes that the needs of research in the Earth sciences and applications should not be continually deferred until the development of new, unproven technologies. The prospect of lower cost is always attractive, but the practice of placing new technology developments ahead of the conduct of basic and applied research has been disruptive to the Earth sciences for more than two decades.l9 PLANETARY SCIENCES Arguments for a Portfolio of Mission Sizes 77 The Space Studies Board's strategy report for the planetary sciences, An Integrated Strategy for the Planetary Sciences: 1995-2010, covers a diversity of topics and objectives, including studies of protoplanetary disks, planetary systems about other stars, primitive bodies, the origin and evolution of life, the surfaces and interiors of solid bodies, and planetary atmospheres, nngs, and magnetospheres.20 The scientific, technical, and operational ~ , ., , ., ~ aspects of planetary exploration require a range of mission sizes.2l 22 Large missions are necessary to approach future high-pnonty scientific goals such as a sample return from a comet nucleus or from the surface of a planet or satellite, a comprehensive survey of a giant planet (with atmospheric and satellite probes)
|
From page 78... ...
contributed Japanese-led mission; NMS instrument U.S. contribution, $6 million Stardust Collect comet material Medium, Ongoing February 1999 380 kg, 7 years $205 million Galileo Jupiter orbiter and probe Large, Ongoing Launched 1988, $ 1,425 million in orbit 1995 Cassini Saturn system including Large, Ongoing October 1997, Titan probe 5,650 kg, over various timescales $2,550 million up to 11 years PLANNED Contour Imaging and spectral maps Small, Planned 2002 of three comets 489 kg, 6 years, 3 flybys $144 million Genesis Solar wind sample return Medium, Planned January 2001 648 kg, 2-yr operations $216 million Messenger Mercury Orbiter Medium (Discovery)
|
From page 79... ...
contribution $6.6 million for ASPERA, $27 million for other contributions) Large, 225 kg, $354 million Planned June 2003 3 years Planned 2004 More than 9 years Criteria for Evaluating the Mission Mix The following criteria are proposed for evaluating the current mix of missions for solar system exploration: Addresses high-priority scientific goals; Optimizes science return for the money spent; Exhibits compatibility between mission goals and scale; Demonstrates a balanced-risk strategy; Considers future application of new technologies; Shows balance between technology and science; Involves community in mission/instrument/technology selection; Promotes stable funding and continuous planetary exploration; Is consonant with Deep Space Network (DSN)
|
From page 80... ...
unless conducted through the Discovery program. Example of a Portfolio of Mission Sizes Table E.3 includes an array of currently operating and planned missions in space and solar physics.
|
From page 81... ...
, Waiting for Launch 3/15/00, boundary layers, and auroras 536 kg, launch 2-yr primary plus $ 154 million extended phase TIMED Energy flow and dynamics in the Medium (STP) , In Launch 7/01, 60- to 180-km region of Earth's $208 million development 2 years of operation atmosphere, by remote sensing Solar B Solar magnetic field evolution at Medium, Phase A/B Launch 2003 photosphere, lower corona 875 kg, $ 154 million (Japanese-led mission)
|
From page 82... ...
In addition to suiting the scientific and physical requirements, a mix of mission sizes provides for continuity and follow-up in the various subfields of space astronomy and astrophysics. To achieve that diversity, the Bahcall committee recommended that the Explorer program be substantially expanded to allow flying six Delta-class astronomy and astrophysics Explorer missions and five SMEX-class missions for astrophysics during the l990s.28 Most of the Delta-class missions would fall into the medium cost category.
|
From page 83... ...
TABLE E.4 Selected Astronomy and Astrophysics Missions Mission Size/Mass/ Spacecraft Parameters/Goals Time Scale of Life-Cycle Costs (real $) Status Observation ONGOING SWAS Submillimeter spectrum molecules in Small, Ongoing December 1998 star-forming regions $97 million present ACE Particles, isotopic, elemental composition Medium, Ongoing August 1997 of planetary and interstellar space $203 million 2-5 years FUSE Far-UV spectrum, deuterium, H2, hot gas Medium, Ongoing June 1999 $204 million 3 years HST Optical, UV, and near-IA observations Large, Ongoing April 1990-present $9.1 billion (including operations, data analysis, and use of shuttle)
|
From page 84... ...
NGST Near-IR/high-redshift galaxies Large, Planned 2008 3,300 kg, 5 years $1,700 million LISA Interferometer/gravitational radiation Large, Under study 2009 with contributions from several countries $ N/A 6 years Constellation-X X rays (imaging and spectroscopy) Large, Planned 2010 $ N/A 3-5 years TPF IR interferometer/planet detection, Large, Planned 2011 processes related to star and planet $ N/A >5 years formation, AGNs FIRST/Planck Image the anisotropies of the cosmic Large, Planned 2003 for FIRST, background radiation field over the $ N/A 2007 for Planck whole sky (ESA missions with NASA contributions)
|
From page 85... ...
29NASA Advisory Council, Space and Earth Science Advisory Committee, The Crisis in Space and Earth Science: A Time for New Commitment, 1986, pp.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.