Venera-D: Expanding our Horizon of Terrestrial Planet Climate and Geology through the Comprehensive Exploration of Venus Venera-D Joint Science Definition Team Authors and Study Participants Name Institution Co-Chairs D. Senske Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA L. Zasova Space Research Institute, Moscow, Russia Joint Science Definition Team Members N. Ignatiev Space Research Institute, Moscow, Russia O. Korablev Space Research Institute, Moscow, Russia N. Eismont Space Research Institute, Moscow, Russia I. Lomakin Lavochkin Association, Moscow, Russia M. Gerasimov Space Research Institute, Moscow, Russia M. Ivanov Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, Russia M. Martynov Lavochkin Association, Moscow, Russia I. Khatuntsev Space Research Institute, Moscow, Russia S. Limaye University of Wisconsin, Madison, WI K. Lea Jessup Southwest Research Institute, Boulder, CO T. Economou University of Chicago, Chicago, IL L. Esposito University of Colorado, LASP, Boulder, CO A. Ocampo NASA Headquarters, Washington, DC The Venera-D JSDT would like to thank and acknowledge the support and contribution to this report provided by: Oleg Vaisberg (IKI RAS) for his contribution to the “Solar Wind-Venus Interaction and Venus Magnetosphere” discussion; Alexander Kosov (IKI RAS) for evaluating the scenario and calculating the volume of data that could be transmitted from the Lander to the Orbiter; and Alexander Simonov (Lavochkin Association) for trajectory calculations. The cost information contained in this document is of a budgetary and planning nature and is intended for informational purposes only. It does not constitute a commitment on the part of JPL and/or Caltech. © 2017. All rights reserved. Table of Contents 1 Executive Summary .................................................................................................................................................1 2 The Allure of Venus ..................................................................................................................................................5 2.1 Introduction ................................................................................................................................................... 5 2.2 The Venera-D Concept ................................................................................................................................. 5 2.3 Baseline Venera-D Concept and Science Priorities ..................................................................................... 6 2.3.1 Mission Elements ............................................................................................................................. 6 2.3.2 Prioritized Overarching Science Goals ............................................................................................ 6 2.4 Venera-D Joint Science Definition Team.................................................................................................... 12 3 Science Background, Current Open Questions and Relation to Venera-D ............................................................15 3.1 The Venus Atmosphere .............................................................................................................................. 15 3.1.1 What We Know About the Venus Atmosphere and Open Questions ............................................ 15 3.1.2 Needed Measurements .................................................................................................................. 26 3.2 Science at the Surface of Venus ................................................................................................................ 28 3.2.1 Venus Geology .............................................................................................................................. 28 3.2.2 Venus Geochemistry ...................................................................................................................... 32 3.3 Traceability of Venera-D Goals and Objectives to the Decadal Survey and VEXAG................................. 36 3.4 Venera-D Science Relative to Ongoing and Potential Other Future Missions ........................................... 49 3.5 Science Gaps ............................................................................................................................................. 49 4 Mission Architecture ...............................................................................................................................................51 4.1 General Architecture ................................................................................................................................... 51 4.1.1 Launch, Cruise, and Orbit Insertion at Venus ................................................................................ 51 4.1.2 The Composite Venera-D Spacecraft ............................................................................................ 54 4.1.3 Communication and Data Transmission ........................................................................................ 55 4.1.4 Spacecraft Mass ............................................................................................................................ 56 4.1.5 Architecture Summary ................................................................................................................... 56 5 Technology, Challenges (CH) and Enablers (EN)..................................................................................................57 5.1 Baseline Mission ......................................................................................................................................... 57 5.2 Other Potential Mission Components ......................................................................................................... 59 5.3 Potential Technology Demonstrations ........................................................................................................ 62 6 Opportunities for Lab Work ....................................................................................................................................63 6.1 Baseline Mission ......................................................................................................................................... 63 6.2 Other Potential Mission Components ......................................................................................................... 63 7 Potential Contributions to the Baseline Venera-D Concept ...................................................................................64 7.1 Aerial Platform ............................................................................................................................................ 64 7.2 Small Long-Lived-Stations .......................................................................................................................... 65 8 JSDT Findings and Recommendations ..................................................................................................................67 8.1 Science That Could Be Achieved by Venera-D .......................................................................................... 67 8.2 Strategic Needs for Future Development ................................................................................................... 69 8.3 Architectural Options .................................................................................................................................. 69 8.4 Assessment of JSDT–Chartered Tasks ..................................................................................................... 70 9 Framework for Future Work ...................................................................................................................................71 10 References .............................................................................................................................................................72 Appendix A: Technology Summary Table .....................................................................................................................80 Venera-D Final Report i List of Tables Table 2.3-1. Venera-D Science from Orbit ......................................................................................................................8 Table 2.3-2. Venera-D Descent and Landed Science ...................................................................................................11 Table 2.4-1. Members of the Venera-D Joint Science Definition Team ........................................................................13 Table 3.2-1. Areas of the most important units from different regimes of resurfacing on Venus ..................................30 Table 3.2-2. Results of chemical analyses conducted by the Venera (V) and VEGA (Vg) landers ..............................33 Table 3.3-1. Mapping of the science capability of Venera-D to the NASA Planetary Decadal Survey .........................37 Table 3.3-2. Mapping of science capability of Venera-D to the VEXAG Objectives and Investigations for Atmospheric Science ..............................................................................................................................................42 Table 3.3-3. Mapping of science capability of Venera-D to the VEXAG Objectives and Investigations for Surface Science .....................................................................................................................................................45