JPL D-37401 B January 30, 2007 Titan and Enceladus $1B Mission Feasibility Study Report Prepared for NASA’s Planetary Science Division Prepared By: Kim Reh Contributing Authors: John Elliott Tom Spilker Ed Jorgensen John Spencer (Southwest Research Institute) Ralph Lorenz (The Johns Hopkins University, Applied Physics Laboratory) KSC GSFC ARC Approved By: _________________________________ Kim Reh Dr. Ralph Lorenz Jet Propulsion Laboratory The Johns Hopkins University, Applied Study Manager Physics Laboratory Titan Science Lead _________________________________ Dr. John Spencer Southwest Research Institute Enceladus Science Lead Pre-decisional — For Planning and Discussion Purposes Only Titan and Enceladus Feasibility Study Report Table of Contents JPL D-37401 B The following members of an Expert Advisory and Review Board contributed to ensuring the consistency and quality of the study results through a comprehensive review and advisory process and concur with the results herein. Name Title/Organization Concurrence Chief Engineer/JPL Planetary Flight Projects Gentry Lee Office Duncan MacPherson JPL Review Fellow Glen Fountain NH Project Manager/JHU-APL John Niehoff Sr. Research Engineer/SAIC Bob Pappalardo Planetary Scientist/JPL Torrence Johnson Chief Scientist/JPL i Pre-decisional — For Planning and Discussion Purposes Only Titan and Enceladus Feasibility Study Report Table of Contents JPL D-37401 B This page intentionally left blank ii Pre-decisional — For Planning and Discussion Purposes Only Titan and Enceladus Feasibility Study Report Table of Contents JPL D-37401 B Table of Contents 1. EXECUTIVE SUMMARY.................................................................................................. 1-1 1.1 Study Objectives and Guidelines............................................................................ 1-1 1.2 Relation to Cassini-Huygens, New Horizons and Juno.......................................... 1-1 1.3 Technical Approach................................................................................................ 1-2 1.4 Costing Methodology..............................................................................................1-4 1.5 Cost Results............................................................................................................ 1-5 1.6 Risk Assessment ..................................................................................................... 1-7 1.7 Science Value..........................................................................................................1-8 1.8 Feasibility Assessment and Conclusions ................................................................ 1-9 1.8.1 Titan Missions.......................................................................................... 1-10 1.8.2 Enceladus Missions.................................................................................. 1-10 1.8.3 Conclusions 1-11 1.9 Recommendations................................................................................................. 1-11 2. METHODOLOGY............................................................................................................... 2-1 2.1 Overview................................................................................................................. 2-1 2.2 Guidelines ............................................................................................................... 2-1 2.3 Team ....................................................................................................................... 2-1 2.4 Approach................................................................................................................. 2-2 2.4.1 Science and Measurement Objectives:....................................................... 2-2 2.4.2 Platforms and Mission Concepts................................................................ 2-2 2.4.3 Science Value............................................................................................. 2-4 2.4.4 Mission Cost............................................................................................... 2-4 2.4.5 Risk 2-4 2.4.6 Assessment of feasibility............................................................................ 2-5 3. TITAN SCIENCE AND PAYLOAD................................................................................... 3-1 3.1 The Importance of Titan – An Appealing and Broad Scientific Target ................. 3-1 3.2 Cassini Limitations and the Foundation for New Science...................................... 3-3 3.3 Titan Science Goals ................................................................................................ 3-3 3.3.1 Sources of Methane.................................................................................... 3-3 3.3.2 Condensation and Cloud Formation........................................................... 3-4 3.3.3 Conversion of Methane to Complex Organics in the Upper Atmosphere . 3-4 3.3.4 Aerosol Formation...................................................................................... 3-4 3.3.5 Surface Organic Inventory ......................................................................... 3-4 3.3.6 Geomorphological Processes and Transport of Organics .......................... 3-4 3.3.7 Surface Composition and Astrobiology ..................................................... 3-5 3.4 Rating and Down Selection of Mission Concepts .................................................. 3-5 3.5 Missions Rejected or Not Considered..................................................................... 3-6 3.6 Missions and Payload Studied ................................................................................ 3-7 3.6.1 Titan Orbiter 3-7 3.6.2 Aerobot 3-7 3.6.3 Long-Lived Lander.................................................................................... 3-8 iii Pre-decisional — For Planning and Discussion Purposes Only Titan and Enceladus Feasibility Study Report Table of Contents JPL D-37401 B 3.6.4 ‘Huygens-Like’ Probe................................................................................ 3-8 4. ENCELADUS SCIENCE AND PAYLOAD....................................................................... 4-1 4.1 The Importance of Enceladus ................................................................................. 4-1 4.2 Enceladus Science Goals ........................................................................................ 4-2 4.2.1 Tidal Heating.............................................................................................. 4-2 4.2.2 Interior Structure ........................................................................................ 4-2 4.2.3 Composition 4-3 4.2.4 Tectonism 4-3 4.2.5 Cryovolcanism ........................................................................................... 4-3 4.2.6 Surface Processes....................................................................................... 4-4 4.2.7 Biological Potential.................................................................................... 4-4 4.3 Cassini Limitations ................................................................................................. 4-4 4.4 Rating and Down Selection of Mission Concepts .................................................. 4-5 4.5 Enceladus Plume Sample Return............................................................................ 4-7 4.6 Saturn Orbiter with Multiple Enceladus Flybys ..................................................... 4-8 4.7 Single Enceladus Flyby: The Simplest Possible Mission..................................... 4-10 5. MISSION ARCHITECTURE CONCEPTS......................................................................... 5-1 5.1 Overview................................................................................................................. 5-1 5.1.1 The Saturn System..................................................................................... 5-1 5.1.2 Architectures Studied................................................................................. 5-2 5.2 Travel to Saturn.......................................................................................................5-2 5.3 Mission Option Trades............................................................................................ 5-4 5.4 Aerocapture............................................................................................................. 5-5 5.5 Mission Architectures............................................................................................. 5-7 5.5.1 Titan Orbiter 5-7 5.5.2 Titan Aerobot............................................................................................. 5-9 5.5.3 Titan Lander 5-11 5.5.4 Enceladus Plume Sample Return ............................................................. 5-12 5.5.5 Saturn Orbiter with Enceladus Flybys ..................................................... 5-14 5.5.6 Titan Entry Probe..................................................................................... 5-16 5.5.7 Enceladus Single Flyby............................................................................ 5-17 6. FLIGHT SYSTEM CONCEPTS.......................................................................................... 6-1 6.1 Overview................................................................................................................. 6-1 6.2 SEP Stage Design ..................................................................................................