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Planetary Science Decadal Survey: Saturn Atmospheric Entry Probe

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Data Release, Distribution, and Cost Interpretation Statements This document is intended to support the SS2012 Planetary Science Decadal Survey. The data contained in this document may not be modified in any way. Cost estimates described or summarized in this document were generated as part of a preliminary, first- order cost class identification as part of an early trade space study, are based on JPL-internal parametric cost modeling, assume a JPL in-house build, and do not constitute a commitment on the part of JPL or Caltech. Costs are rough order of magnitude based on architectural-level input and parametric modeling and should be used for relative comparison purposes only. These costs are not validated for budgetary planning purposes. Cost reserves for development and operations were included as prescribed by the NASA ground rules for the Planetary Science Decadal Survey. Unadjusted estimate totals and cost reserve allocations would be revised as needed in future more-detailed studies as appropriate for the specific cost-risks for a given mission concept. Saturn Atmospheric Entry Probe Trade Study i Planetary Science Decadal Survey Mission Concept Study Final Report Study Participants ........................................................................................................ iv Acknowledgments ......................................................................................................... v Executive Summary ..................................................................................................... vi Study Purpose, Objectives, and Approach .............................................................. viii 1. Scientific Objectives ............................................................................................ 1 Science Questions and Objectives ............................................................................................... 1 Science Traceability ...................................................................................................................... 5 2. High-Level Mission Concept ............................................................................... 6 Mission Overview .......................................................................................................................... 6 Concept Maturity Level ................................................................................................................. 7 Technology Maturity ...................................................................................................................... 7 Key Trades .................................................................................................................................... 8 3. Technical Overview ............................................................................................ 13 Instrument Payload Description .................................................................................................. 13 Flight System .............................................................................................................................. 15 Technology Description .............................................................................................................. 19 Concept of Operations and Mission Design ................................................................................ 20 Planetary Protection .................................................................................................................... 26 Risk List ...................................................................................................................................... 27 4. Development Schedule and Schedule Constraints ......................................... 28 High-Level Mission Schedule ...................................................................................................... 28 Technology Development Plan ................................................................................................... 28 Development Schedule and Constraints ..................................................................................... 28 5. Mission Life-Cycle Cost ..................................................................................... 29 Potential Cost-Saving Options .................................................................................................... 29 6. Integrated Assessment and Conclusions ........................................................ 31 Saturn Atmospheric Entry Probe Trade Study ii Figures Figure 3-1. Reference Mission Transfer Trajectory .................................................................................... 23 Figure 3-2. Reference Probe Entry and Saturn Flyby Trajectories ............................................................. 25 Figure 3-3. Variation in Range and Zenith Angle During Communication Window ................................... 25 Figure C-1. Comparison of Proposed Saturn Probes with Galileo Probe .................................................. 37 Tables Table 1-1. Elemental (relative to H) and Isotopic Abundances [5]................................................................ 2 Table 1-2. Science Traceability Matrix .......................................................................................................... 5 Table 2-1. Concept Maturity Level Definitions .............................................................................................. 7 Table 3-1. Mass Spectrometer .................................................................................................................... 14 Table 3-2. Atmospheric Structure Instrument ............................................................................................. 14 Table 3-3. Payload Mass and Power .......................................................................................................... 15 Table 3-4. Conceptual CRSC Characteristics ............................................................................................. 17 Table 3-5. Conceptual Probe Characteristics ............................................................................................. 18 Table 3-6. Study Reference Mission Design ............................................................................................... 26 Table 4-1. Key Phase Duration ................................................................................................................... 28 Appendices A. Acronyms B. References C. Comparison of Saturn Probes to Galileo Probe Saturn Atmospheric Entry Probe Trade Study iii Study Participants Role Participant Affiliation Study Lead and Primary Author Dr. Thomas R. Spilker Jet Propulsion Laboratory Giant Planets Panel Contributing Authors Science Champion Prof. Reta Beebe New Mexico State University Science Dr. Heidi Hammel Space Science Institute Science Dr. Amy Simon-Miller NASA Goddard Space Flight Center Science R. Wayne Richie NASA Langley Research Center (ret.) Science Dr. Kuniyo M. Sayanagi California Institute of Technology Saturn Probe Trade Study Team Systems Engineer Cate Heneghan Jet Propulsion Laboratory Mission Design George Carlisle Jet Propulsion Laboratory Mission Design Jeff Parker Jet Propulsion Laboratory Power Paul Stella Jet Propulsion Laboratory Propulsion Frank Picha Jet Propulsion Laboratory Systems Engineer Omair Khan Jet Propulsion Laboratory Telecom Systems Dave Morabito Jet Propulsion Laboratory Consultant Tibor Balint Jet Propulsion Laboratory JPL SS 2012 PSDS Trades Lead Chet Borden Jet Propulsion Laboratory JPL SS 2012 PSDS Lead Kim Reh Jet Propulsion Laboratory NASA HQ POC Leonard Dudzinski NASA The study team would like to thank the following for their valuable contributions: Prof. David Atkinson Prof. Sushil Atreya Dr. Anthony Colaprete Dr. Paul Mahaffey Dr. Ethiraj Venkatapathy Saturn Atmospheric Entry Probe Trade Study iv Acknowledgments This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. © 2010. All rights reserved. Saturn Atmospheric Entry Probe Trade Study v Executive Summary This study found it might be possible to implement a Saturn probe mission in which a flyby carrier-relay spacecraft (CRSC) would deliver a single probe within the resource constraints of NASA’s New Frontiers Program. Achievement of this goal would require a small and focused set of science objectives. The mission’s science objectives, specified by the study science team, are divided into two groups: “Tier 1,” essentially the science floor objectives that must be addressed to make the mission worthwhile, and “Tier 2,” the next highest priority level, with objectives that prospective PIs could reasonably add, given sufficient resources. By request from the science team, this study used as requirements only the Tier 1 objectives: Determine the noble gas abundances and isotopic ratios of H, C, N, and O (and Ar?) in Saturn’s atmosphere Determine the atmospheric structure at the probe descent location(s) The primary objective of this study was to determine whether any probe mission capable of accomplishing these science objectives could fit within the New Frontiers constraints. A secondary objective was to determine if a single mission delivering two such entry probes to different locations at Saturn might fit within New Frontiers constraints. This secondary objective was judged unlikely early in the study and was removed from further consideration.
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