Pre-Decisional — For Planning and Discussion Purposes Only Science from the Europa Clipper Mission Concept: Exploring the Habitability of Europa D. Senske1, L. Prockter2, R. Pappalardo1, M. Mellon3, W. Patterson2, S. Vance1, B. Cooke1, and the Europa Study Team 1Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA 91109, 2Johns Hopkins Applied Physics Laboratory, Laurel, MD, 20723, 3Southwest Research Institute, Boulder, CO 80302. Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Background The NRC Decadal Survey deemed the Jupiter Europa Orbiter (JEO) mission concept to be of extremely high science value, but unaffordable, and viable descoped options were requested A 1.5 year study developed mission options that retain high science value at significantly reduced cost: the “Clipper” (multiple flyby), a simplified Europa Orbiter, and a Lander (report to NASA, May 2012) Focus now on Europa Clipper concept The Europa Clipper (Multiple-Flyby in Jupiter Orbit) Europa Orbiter Europa Lander Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Europa Science: Goal, Habitability Themes, and Objectives Goal: Explore Europa to investigate its habitability Habitability Themes: Water: Solvent to facilitate chemical reactions Chemistry: Constituents to build organic molecules Energy: Chemical disequilibrium for metabolism Objectives: Ocean: Existence, extent, and salinity Ice Shell: Existence and nature of water within or beneath, and nature of surface-ice-ocean exchange Composition: Distribution and chemistry of key compounds and the links to ocean composition Geology: Characteristics and formation of surface features, including sites of recent or current activity water chemistry energy habitability Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Europa Clipper: Science Investigations and Model Planning Payload Science Objective Key Science Investigations Model Instrument Similar Instrument Ocean & Ice Shell Time-varying gravity field through Doppler tracking, to detect ocean and determine interior structure. Radio Sub-system (RS); Independent Gimbaled Antenna Magnetic induction response, to derive ocean thickness and salinity. Local plasma and electric field, to support magnetic induction experiment. Magnetometer (MAG) with Langmuir Probe (LP) Juno MAG Rosetta LAP Sounding of dielectric horizons at two frequencies, to search for shallow water and the ocean. Ice-Penetrating Radar (IPR) MRO SHARAD Composition Visible and near-infrared spectroscopy, for global mapping and high-resolution scans, to derive surface composition. ShortWave IR Spectrometer (SWIRS) LRO M3 Elemental, isotopic, and molecular composition of the atmosphere and ionosphere, during close flybys. Neutral Mass Spectrometer (NMS) Nozomi Geology Medium to High resolution stereo imagery, to characterize geological landforms, and to remove clutter noise from IPR data. Topographical Imager (TI) New Horizons Ralph/MVIC Floor model instrument Baseline model instrument Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Europa Clipper Concept Summary Jan. 2013 Science: Operations Concept: 32 low altitude flybys of Europa from Jupiter orbit over 2.3 years Detailed investigation of globally distributed regions of Europa Simple repetitive science operations Addition of high resolution reconnaissance camera and thermal imager Magnetometer (Mag) Payload: Langmuir Probe (LP) (x2) Neutral Mass Spectrometer (NMS) Ice Penetrating Radar(IPR) Thermal Imager (Thermal) Remove cost Highlight changes Shortwave Infrared Spectrometer (SWIRS) Gravity Science Antenna (GS) Recon Camera (Recon) Technical Margins 48% 40% 62% Mass Power Data Topographical Imager (TI) Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Innovative Mission Design Dense, globally distributed network of intersecting ground tracks Enables globally distributed coverage through multiple flybys Minimizes time in high radiation environment Multiple Europa Flybys minimize radiation exposure Flyby groundtracks Europa Orbit Radiation Belts Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Model Instrument Surface Coverage SWIR Spec. - Low Res Ice Penetrating Radar –––––– 25 – 400 km (primary data collection) –––––– 400 – 1,000 km (extended data collection) SWIR Spec. – High Res Topographic Imager (altitudes ≤4000 km) High-res swaths at better than 100 m/pixel Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Europa Clipper Operations Concept Simple and Repetitive Magnetometer and Langmuir Probes Continuous measurements ShortWave InfraRed Spectrometer (SWIRS) Global low resolution scan below 66,000 km altitude Targeted high resolution scan below 2,000 km altitude Passive below 1,000 km altitude Gravity Science Measurements below 28,000 km altitude Topographical Imager (TI) Pushbroom stereo imaging below 1,000 km altitude Lower res. pushbroom imaging between 4,000 and 1,000 km altitude Ice Penetrating Radar (IPR) Surface scans below 1,000 km altitude Mass Spectrometer (NMS) In situ scan below 1,000 km altitude Recon Camera High resolution imaging below 105 km altitude Thermal Imager Pushbroom thermal imaging below 60,000 km Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Key Science Questions for Europa Objective Clipper 1. What are the properties and characteristics of Europa’s ocean? Ocean  ✓ 2. How thick is the icy shell? Ice Shell  ✓  3. Is there near-surface water within the ice shell? ✓  4. What is the global distribution of geological features? Geology 5. Is liquid water involved in surface feature formation? Geology/Ice Shell 6. Is the icy shell warm and convecting? 7. What does the red stuff tell us about ocean composition? Composition 8. How active is Europa today? 9. What is the plasma and radiation environment at Europa? Ocean/Composition   10. What is the nature of organics and salts at Europa? 11. Is chemical material from depth carried to the surface? ✓ 12. Is irradiation the principal cause of alteration of Europa’s surface material through time? Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Programmatic Need for Feed-Forward Reconnaissance Data Sets Cassini Enceladus 4 m/pixel Reconnaissance data is necessary to feed forward to a future lander mission: required to evaluate landing safety Observation Purpose High Resolution Imaging Map block abundance. Characterize ≥ meter-scale surface roughness. Stereo Imaging Maps surface slopes for lander tilt hazard, terrain relative navigation. Thermal IR Imaging (Brightness Temperature and Bolometric Albedo) Verify visible block abundance & extrapolate to submeter scale. Validate average surface roughness & extrapolate. Identify regolith cover. Galileo PPR Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Europa Clipper Configuration Shortwave Infrared Spectrometer (SWIRS) Ice Penetrating Radar(IPR) Topographical Imager (TI) Magnetometer (Mag) Gravity Science Antenna (GS) Neutral Mass Spectrometer (NMS) Langmuir Probe (LP) (x2) Thermal Imager (Thermal) Recon Camera (Recon) Europa Clipper Configuration The technical data in this document is controlled under the U.S. Export Regulations; release to foreign persons may require an export authorization Pre-Decisional — For Planning and Discussion Purposes Only 1/29/13

Europa Clipper Spacecraft Benefits of Modular Configuration Implementation flexibility Parallel integration paths Module level integrated testing during Phase C Isolates implementation issues at the module level Robust schedule management Decouples qualification testing until late in integration flow Allows for integration of ASRGs at KSC Smooth funding profile Minimizes peaks in project funding profile Allows flexible phasing of module implementation schedules High Gain Antenna Star Tracker (x2) Avionics Module Reaction Wheels (x4) Avionics Vault Fuel Tank (x2) Oxidizer Tank (x2) Propulsion Module Thruster Cluster Assemblies (x4) Main Engine He Pressurant Tank (x2) ASRG Control Electronics (x4) Power Source Module ASRG (x4) The technical data in this document is controlled under the U.S. Export Regulations; release to foreign persons may require an export authorization Pre-Decisional — For Planning and Discussion Purposes Only 1/29/13

Radiation Mitigation Approach Effective Shield Thickness Resulting End of Mission Dose ß 100 mil Al 2.1 Mrad (End of Mission Total Dose) Tank Wall 200 mil Al 900 krad Propellant Primary Structure 400 mil Al 350 krad Vault 600 mil Al 150 krad Chassis 800 mil Al 110 krad Card Location 1000 mil Al 80 krad (End of Mission Total Dose) Allows use of existing industry geosynchronous class parts The technical data in this document is controlled under the U.S. Export Regulations; release to foreign persons may require an export authorization Pre-Decisional — For Planning and Discussion Purposes Only 1/29/13

Pre-Decisional — For Planning and Discussion Purposes Only Power System Options ASRG: Advanced Stirling Radioisotope Generator Recommended by Planetary Decadal Survey Technical issues need resolution for compatibility with Europa Mission Reliability not yet demonstrated; high per unit cost 25.8 m 3.0 m 11.4 m Solar: Foldout Panel Solar Arrays Technical issues must be resolved before determining feasibility for Europa Mission Reliability uncertain in high radiation environment. Highest mass, lowest cost solution. MMRTG: Multi-Mission Radioisotope Thermoelectric Generator JEO baseline power source still feasible for redesigned Europa Mission Highest 238Pu usage; concern diminished by 238Pu production restart Demonstrated high reliability Mass and cost impact bounded by Solar and ASRG Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Europa Clipper Cost Estimates Cost: Phases A-F, no LV (FY15$) Model May 2012: No Ocean Science or Recon (ASRG) May 2012: Aerospace CATE Oct. 2012: w/ Ocean Science & Recon PRICE-H $1.96B $2.11B $2.07B SEER-H $1.91B $2.05B Performed cost modeling as was done for NRC Planetary Decadal Survey (Aerospace CATE) in addition to other parametric models as a check Changes from May 2012 to Oct. 2012 cost estimates: Updated Flight System cost estimates based on Oct. 2012 Master Equipment Lists (MELs) Updated instrument cost estimate for IPR based on independent assessment Updated instrument cost estimates for all other instruments using NICM (subsystem mode) Included additional instrument costs as applicable for Ocean Science & Recon Updated science and operations estimates Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. The cost information contained in this document is of a budgetary nature and is intended for informational purposes only. It does not constitute a commitment on the part of JPL and/or Caltech. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Assessment of Clipper by NRC and NASA Committees Committee on Astrobiology and Planetary Sciences (CAPS) Assessment to Planetary Science Subcommittee (PSS) (10/3/12): The Europa study team has developed excellent orbiter and flyby (“Clipper”) concepts that are robust and feasible, and are responsive to the Decadal Survey, the current budget constraints, and the need for balance in the Planetary Program The multiple flyby “Clipper” element is favored because it addresses the preponderance of the science objectives laid out in the Decadal Survey Independent review by a CATE process (the same used in the Decadal Survey) affirms that the costs for the orbiter and Clipper are credible and that the risk is low The Clipper mission has excellent scientific value Clipper mission concept is well thought out and realistic Radiation issues have been well addressed High resolution imaging, if possible without significant growth in cost or complexity, would be an excellent “feed forward” element for a future lander mission Copyright 2012 California Institute of Technology. Government sponsorship acknowledged. Pre-Decisional — For Planning and Discussion Purposes Only 1/31/13

Europa Clipper