VEXAG Presentation to PSS October 7, 2007 Orlando, Florida

Transcription

1 VEXAG Presentation to PSS October 7, 2007 Orlando, Florida by Janet Luhmann (for the VEXAG Steering Committee: CoChair Sushil Atreya, Focus Group Leads Steve Mackwell and Kevin Baines, Technology Leads Jim Cutts and Tibor Balint, NASA Program representative Tommy Thompson, Ellen Stofan, Larry Esposito)

2 VEXAG (Venus Exploration Analysis Group) VEXAG Meetings to Date: -Kickoff Meeting November 4, 2005, Pasadena -Related Venus Chapman Conference, Feb. 06 -First working meeting May 1-2, 2006, Pasadena -Second Meeting held in Crystal City, VA on Jan 11-12, Next meeting scheduled for November 4-5, 2007 in Greenbelt, MD in conjunction with the Planetary Atmospheres Program Conference 2

3 Current VEXAG Activities and Issues Completing our Report ( White Paper ) outlining Key Science Questions and Goals for Venus Explorationnow available Promoting developments in extreme environment technologies Organizing Venus Flagship Mission STDT kickoff Engaging the Earth Science Community in Comparative Planetology (e.g. at the upcoming VEXAG #4 meeting) Supporting Venus Express, Venus Climate Orbiter, and now EVE activities Providing support to the NRC NOSSE committee 3

4 Report Highlights: Outstanding Questions in Venus Exploration Was a Venus ocean lost, and if so, what caused it to disappear? What is the origin of the superrotation of the Venus atmosphere? When did the Venus greenhouse effect dominate and what implications does this have for the future of the Earth? Was there an ancient magnetic field on Venus and is a record preserved in surface rocks? Why does Venus rotate so slowly and what does it tell us about the formation and early evolution of the planet? What is the nature of the global cataclysm that resurfaced Venus and when did it occur? What are the implications of Venus for the detection of extrasolar terrestrial planets? Was Venus ever habitable and is there evidence for life early in the planet s history? 4

5 VEXAG Report: Venus Exploration Goals and Objectives VEXAG s Analysis translated these Questions into Three Major Goals for Venus Exploration: I. Origin and Early Evolution of Venus: How did Venus originate and evolve, and what are the implications for the characteristic lifetimes and conditions of habitable environments on Venus and similar extrasolar planets? II. Venus as a terrestrial planet: What are the processes that have and still shape the planet? III. What does Venus tell us about the fate of Earth s environment? VEXAG Web-Site -

6 The Challenge: Extreme Environments for Venus In-Situ Missions Greenhouse effect results in VERY HIGH SURFACE TEMPERATURES Average surface temperature: ~ 460 to 480 C Average pressure on the surface: ~ 92 bars Cloud layer composed of aqueous sulfuric acid droplets at ~45 to ~70 km attitude From surface to ~10 km Ref: N.Yajima, N.Izutsu, H.Honda, K.Goto and T.Imamura (ISAS) N.Tomita and K.Akazawa (Musashi Institute of Technology Univ.) Feasibility and Applicability of Planetary Balloons, Website: Sci_Bal/engplanetary.html Target region for VME Venus atmosphere is mainly CO 2 (96.5%) and N 2 (3.5%) with: small amounts of noble gases (He, Ne, Ar, Kr, Xe) small amount of reactive trace gases (SO 2, H 2 O, CO, OCS, H 2 S, HCl, SO, HF ) Zonal winds: at near surface ~1 m/s; while at 60 km altitude ~ 60+ m/s 6 Ref: E. Kolawa, Extreme Environments Technologies

7 Key Extreme Environment Technologies Protection systems: Hypervelocity Entry Pressure Mitigation Temperature Mitigation High-Temperature Electronics Power Storage Power Generation Mobility Technologies Balloon and Parachute Materials Sample Acquisition & Mechanism Telecommunication Issues Testing for Extreme Environments 7

8 NASA s 2006 Solar System Exploration Roadmap In the Solar System Roadmap team considered both the Venus In Situ Explorer (VISE) and Venus Surface Sample Return missions recommended by the NRC s Decadal Survey. The Roadmap Team also proposed a Venus Mobile Explorer (VME) mission as the next logical step after VISE, before a sample return mission. VEXAG has now played a key role in initiating an STDT to study a Flagship mission capable of long duration on the surface and extensive mobility. Ref: NASA SMD PSD SSE Roadmap Team, Solar System Exploration Solar System Exploration Roadmap for NASA's Science Mission 8 Directorate, NASA Science Missions Directorate, Planetary Science Division, Report Number: JPL-D-35618, September 15, 2006.

9 NASA s Solar System Roadmap Team Recommendations for the first Venus Flagship Mission Venus Mobile Explorer (VME) is the next logical step in the exploration of Venus after the New Frontiers VISE mission. VME would: Operate on the surface of Venus for >90 days Sample the surface at local and possibly regional scales. Search for granitic and sedimentary rocks indicative of an ancient ocean Lay the scientific and technological ground work for a subsequent Venus Surface Sample Return VME is a technologically challenging mission requiring an investment in technologies for Surviving and operating in the severe environment of Venus (high temperature, pressure, sulfuric acid) Power RPS is only option for long duration operation Mobility on the surface or in the lower atmosphere Measurement techniques suited to the Venus environment. VME would benefit from technologies demonstrated on VISE 9

10 Solar System Roadmap Team Scenarios Leading to Venus Surface Sample Return Planned, Candidate & In-flight Missions by Decade and Category Inner Planets Class Venus Express (ESA) Science feedforw ard Venus In Situ Explorer (VISE) Geophysical Network - Venus Venus Surface Explorer Venus Atmospheric Ascent Tech Expt. Venus Sample Return NF NF I F New Frontiers Flagship Missions Science & Tech FF Extreme Environments Mercury Sample Return Mars Sample Return South Pole Aitken Basin SR (Moonrise) NF Tech FF? Tech FF Autonomous Rendezvous Earliest Flight Opportunities A-1 A-2 A-3 B-1 B-2 F-1 I-1 F-2 F-3 LEGEND Class: NF - New Frontiers, D - Discovery, I - Intermediate, F - Flagship Fly By Orbiter In-Situ Exploration Sample Return Technology Experiment Presentation to Solar System Exploration Roadmap Team Feb 3,

11 VEXAG Findings Technology Investments There are credible technical approaches, leveraging from and building upon technologies developed in industry, to achieving extended operation in the Venus environment. High temperature electronics can enable systems to operate for extended periods. Advanced radioisotope power systems and active thermal control systems could enable conventional components such as microprocessors or imaging sensors to operate for extended periods on the surface of Venus. While further work on mission architectures will be needed to define specific performance goals and focus the technology, work on the technology can and should begin now. Without NASA direct involvement, it will not be possible to apply the results from industry to the specific needs of in situ exploration. 11

12 VEXAG Proposed Actions Technology Investments A program is needed to develop technologies for operation in the extreme environment of Venus that include: Passive thermal control technologies for extending the period of operation in the Venus surface and near surface environment from hours to days. Active thermal control technologies and power generation systems for extending the period of operation in the Venus environment to many months. High temperature electronics and other components capable of extended operation directly exposed to the Venus surface environment Mobility systems for operation at the surface and in the lower atmosphere of Venus This program should be mission-driven and systems analyses to establish performance objectives and align the program with mission needs is required 12

13 VEXAG Findings New Frontiers Missions 1 VEXAG considers that the Venus In Situ Explorer (VISE) science described in the NF AO continues to be the next step in the exploration of Venus, and should be included in the FY08 New Frontiers AO. In addition to its scientific value, the VISE mission offers a unique opportunity to demonstrate capabilities that would be important to a future Flagship mission. However, under the current wording in the call for proposals, any technological capabilities necessary for VISE would have to be sufficiently low risk to pass the technical selection filters, and any purely technology development element of the mission (e.g. for VME) could not be included without the application of standard screening for flight readiness and value to the mission s science. Note 1 Letter report from VEXAG Co-chairs Sushil Atreya and Janet Luhman to Jim Green, Feb

14 VEXAG Proposed Actions New Frontiers Missions 1 The Venus In Situ Explorer (VISE) should be included in the New Frontiers AO for 2008 and the general scientific goals for this mission should remain unchanged. Consideration should be given to increasing the funding level for New Frontiers to assure the success of the mission. NASA should consider implementing a technology validation element to VISE in particular that would permit demonstration of technologies needed for a long duration mobile mission but not necessary to the success of VISE itself. Note 1 Letter report from VEXAG Co-chairs Sushil Atreya and Janet Luhman to Jim Green, Feb

15 VEXAG Findings Venus Flagship Mission The completion by VEXAG of a list of scientific goals and priorities now makes it timely to initiate a study of the next Venus Flagship mission in order to define a concept in more detail, and to identify the technologies needed to implement the mission. A Venus Flagship mission study should not be viewed as part of the competition for the next Flagship mission as it is already clear that a significant and sustained program of technology development is needed to prepare for that mission and a New Frontiers precursor mission to the Venus surface should precede the Flagship mission. However, this study should not be delayed because a path to addressing specific technology challenges the resulting mission concept raises must be embarked upon at the earliest opportunity. 15

16 VEXAG Proposed Actions Venus Flagship Mission A Science and Technology Definition Team (STDT) including a broad and representative set of the community should guide the study of a Venus Flagship Mission The study should assess: Key scientific questions that can be addressed by a long duration mobile mission to the surface or near surface of Venus. Alternative missions architectures for addressing these scientific questions (charting the path to Venus Sample Return) Precursor scientific measurements and technology validation that might be implemented with prior Discovery and New Frontiers missions. Technology investments needed to enable the Venus Flagship mission emphasizing the long lead time technologies needing early investment. 16

17 Take Home Messages There is a lot of exciting and important science to do above and on Venus, our closest neighbor in the solar system. Venus proximity to earth makes it a highly accessible target Important science can be accomplished with existing technologies to address Venus science objectives including missions under the New Frontiers program However, investments in new technologies are required for next major steps forward in exploration following the scientific exploration pathway established for Mars Technology demonstrations in early missions will retire risk for later missions and should be considered as desirable and acceptable part of a New Frontiers mission to Venus 17

18 (Venera data post-processed by Don P. Mitchell) Robots have been there. We can do it again with more/better capabilities. 18

19 Recent Developments Planning for Venus Flagship Mission study (to be carried out by an official STDT) patterned on Outer Planet Studies was initiated at a JPL workshop on July 31. The findings of this group will help to kickoff the STDT activity to be carried out in the next year. Current focus of the planned STDT study covers Flagship mission architectural options along the pathway from a long-lived mobile in situ mission (e.g. a VME) to Venus Surface Sample Return Dr. Jim Green has asked JPL to also explore technologies that could be developed as a part of the lower cost missions, including New Frontiers missions, and so accomplished much earlier The STDT chairs (for science and technology) are currently awaiting confirmation of their appointments, and the solicitation for membership will appear soon. VEXAG will have a new chair shortly (also in process of confirmation) 19

20 VEXAG NASA Planetary Atmospheres Workshop OPAG November 4-9, 2007 Greenbelt Marriott Hotel Sunday - Nov. 4 (half-day) and Monday - Nov. 5 - VEXAG Meeting #4, Tuesday and Wednesday - Nov NASA Workshop on Planetary Atmospheres, Thursday and Friday Nov Outer Planet Analysis Group

21 VEXAG Meeting #4 - Sunday November 4, Afternoon 12:30 PM - Sign-In / Pick-up Handouts / Coffee and Pastries 1:00 PM - VEXAG Meeting #3 Overview and Objectives - Sushil Atreya and Janet Luhmann 1:15 PM - VEXAG Goals and Objectives Document Steve Mackwell 1:45 PM - Venus Mission Architectures and Technology Developments Jim Cutts and Tibor Balint 2:00 PM Recap of International Planetary Probes Workshop Jim Cutts 2:15 PM - European Venus Explorer Proposal and ESA's Cosmic Vision Program Eric Chassefiere 2:30 PM - Coffee Break 2:45 PM - Education and Public Outreach Rosalyn Pertzborn 3:00 PM - Preview of OPAG Meeting Sushil Atreya for Fran Bagenal 3:15 PM - Special Science Briefing Venus Express VIRTIS Science Results - Pierre Drossart / Giuseppe Piccioni 3:45 PM - Open Mike Presentations (1-2 slides, up to 10 minutes) 4:30 PM - Planetary Science Summer School Venus Mission Study 4:50 PM Preview of Monday s Activities Sushil Atreya and Janet Luhmann 5:00 PM - ADJOURN

22 VEXAG Meeting #4 Monday November 5, :30 AM - Sign-In / Pick-up Handouts / Coffee and Pastries 9:00 AM - NASA Headquarters Perspective on Venus Exploration - Jim Green and Andy Cheng 9:30 AM - Status Report: ESA's Venus Express - Hakan Svedhem 9:50 AM - JAXA's Venus Climate Orbiter - Masato Nakamura and Takeshi Imamura 10:10 AM - NASA S Discovery Candidate VESPER Gordon Chin 10:30 AM Coffee Break 10:45 AM - MESSENGER Flybys Sean Solomon, Hakan Svedhem 11:15 PM Evidence for Past Oceans on Venus Mark Bullock 12:00 LUNCH 1:15 PM Preview of Workshop on Planetary Atmospheres - Phil Crane 1:30 PM - Venus-Earth Climate Connections Special Session 4:45 PM - Wrap-up - Next Meeting - Recommendations - Action Items - Sushil Atreya and Janet Luhmann 5:15 PM ADJOURN

23 VEXAG Meeting #4 Monday Afternoon November 5, :30 PM - Venus-Earth Climate Connections (25-minutes each) o Greenhouse Effect and Radiative Balance on Earth and Venus - Dave Crisp o Climate Sensitivity and History of Venus and Earth - Mark Bullock o Aerosols on Earth and Venus - Brian Toon 2:45 Coffee Break (15 Minutes) o Atmospheric Dynamics of Venus and Earth - Jerry Schubert o Solar History Effects on Venus and Earth Climate Janet Luhmann for David Brain o Sulfur Isotope Ratios and Constraints on Climate - Alex Pavlov 4:15 General discussion - Venus-Earth Climate Connections (all) 4:45 PM - Wrap-up - Next Meeting - Recommendations - Action Items - Sushil Atreya and Janet Luhmann 5:15 PM ADJOURN

24 VEXAG wishes to thank Elizabeth Kolawa, Tibor Balint and their technology development team members at JPL for their ongoing support and inputs to this presentation Further thanks to the Planetary Program supporters of VEXAG: Adriana Ocampo at NASA HQ, and Tommy Thompson, Venus Program Lead at JPL. This content results from the collective efforts of the members of the Venus Exploration Analysis Group 24

25 Back Up Charts Mission Descriptions 25

26 Scientific Objectives: Composition and isotopic measurements of surface and atmosphere Near IR descent images Acquire and characterize a core sample. Demonstrate key technologies for VSSR Mission & LV Class: New Frontiers Class Launch Vehicle Class: TBD Roadmap Strawman New Frontiers Mission: Venus In Situ Explorer VISE Science Payload: Neutral mass spectrometer with enrichment cell. Instruments to measure elements and mineralogy of surface materials. Imaging microscope Technology & Heritage:. Sample acquisition and handling in Venus environment Passive insulation and survival at Venus Mission Technology Studies: Decadal Survey 2002 of Surface & Atmospheric In Situ Explorer (SAIVE) JPL proposal in response to New Frontier Mission solicitation. Technology studies in In Space Propulsion, Low temperature materials and autonomy. 26 POC: Tibor.Balint@jpl.nasa.gov

27 Proposed Roadmap Mission: Flagship Class Venus Mobile Explorer (VME) Measurement Objectives: Survey imaging at a variety of spatial scales Acquire & characterize surface samples at multiple sites Other physical and chemical measurements TBD OR Surface Rover Exploration Metrics: Operate in Venus surface environment for 90 days+ Mobility attributes TBD Technology Heritage from Prior Missions: Sample acquisition and handling in Venus environment Thermal control technology Aerial Platform (recommended by the Roadmap Team) New Technology Capabilities: (Maybe a Long Duration Static Lander as descope) Mobility on surface or through the atmosphere Long duration operation at or near the surface 27 POC Tibor.Balint@jpl.nasa.gov

28 Proposed Roadmap Mission: Flagship Class Venus Surface Sample Return VSSR Science objectives: Measure isotopic composition of oxygen in surface rocks Measure isotopic composition of trace elements to characterize core and mantle formation. Determine the age of returned rocks. Exploration Metrics: Return samples of Venus rock soil and atmosphere for analysis on Earth TBD year turnaround mission TBD weeks on the surface Mission & LV Class: Flagship Class LV- TBD Science Payload: As needed for sample identification. Sampling arm and in situ instrumentation Technology & Heritage: Rendezvous and Sample Return Systems from Mars Sample Return missions Balloon technology demonstrated in VISE mission to deliver sample to ascent vehicle launch altitude Ascent vehicle capable of surviving on the surface of Venus and launched from 65 km altitude to orbit Mission Technology Studies: Decadal Survey, POC:

29 VME Example Summary of Enabling Technologies Technologies must mitigate the extreme environments - High temperature (~460 C) - High pressure (~92 bars) - Corrosion (supercritical CO 2 ) Long-lived in-situ exploration of Venus requires significant technology development, that is common to all mission architectures VME aerial mobility / rover / static lander 29 Venus Mobile Explorer - VME: artist s concept