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The Polar Stratosphere of Jupiter

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arXiv 2024年

作者： Hue, Vincent Cavalié, Thibault Sinclair, James A. Zhang, Xi Benmahi, Bilal Rodríguez-Ovalle, Pablo Giles, Rohini S. Stallard, Tom S. Johnson, Rosie E. Dobrijevic, Michel Fouchet, Thierry Greathouse, Thomas K. Grodent, Denis C. Hueso, Ricardo Mousis, Olivier Nixon, Conor A. Aix-Marseille Université CNRS CNES Institut Origines LAM Marseille France Laboratoire d’Astrophysique de Bordeaux Univ. Bordeaux CNRS B18N allée Geoffroy Saint-Hilaire Pessac33615 France LESIA Observatoire de Paris Université PSL Sorbonne Université Université Paris Cité CNRS 5 place Jules Janssen Meudon92195 France Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Dr PasadenaCA91109 United States Department of Earth and Planetary Sciences University of California Santa Cruz Santa CruzCA95064 United States Laboratory for Planetary and Atmospheric Physics STAR Institute University of Liege Liege Belgium Space Science and Engineering Division Southwest Research Institute San AntonioTX United States Department of Mathematics Physics and Electrical Engineering Northumbria University Newcastle upon Tyne United Kingdom Department of Physics Aberystwyth University Ceredigion United Kingdom Escuela de Ingeniería de Bilbao Universidad del País Vasco UPV/EHU Bilbao Spain Solar System Exploration Division NASA Goddard Space Flight Center GreenbeltMD20771 United States

Observations of the Jovian upper atmosphere at high latitudes in the UV, IR and mm/sub-mm all indicate that the chemical distributions and thermal structure are broadly influenced by auroral particle precipitations. Mid-IR and UV observations have shown that several light hydrocarbons (up to 6 carbon atoms) have altered abundances near Jupiter’s main auroral ovals. Ion-neutral reactions influence the hydrocarbon chemistry, with light hydrocarbons produced in the upper stratosphere, and heavier hydrocarbons as well as aerosols produced in the lower stratosphere. One consequence of the magnetosphere-ionosphere coupling is the existence of ionospheric jets that propagate into the neutral middle stratosphere, likely acting as a dynamical barrier to the aurora-produced species. As the ionospheric jets and the background atmosphere do not co-rotate at the same rate, this creates a complex system where chemistry and dynamics are intertwined. The ion-neutral reactions produce species with a spatial distribution following the SIII longitude system in the upper stratosphere. As these species sediment down to the lower stratosphere, and because of the progressive dynamical decoupling between the ionospheric flows and the background atmosphere, the spatial distribution of the auroral-related species progressively follows a zonal distribution with increasing pressures that ultimately produces a system of polar and subpolar hazes that extends down to the bottom of the stratosphere. This paper reviews the most recent work addressing different aspects of this environment. © 2024, CC BY.

关键词： Ionospheric measurement

The InSight-HP3 mole on Mars: Lessons learned from attempts to penetrate to depth in the Martian soil

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arXiv 2021年

作者： Spohn, Tilman Hudson, Troy L. Witte, Lars Wippermann, Torben Wisniewski, Lukasz Kedziora, Bartosz Vrettos, Christos Lorenz, Ralph D. Golombek, Matthew Lichtenheldt, Roy Grott, Matthias Knollenberg, Jörg Krause, Christian Fantinati, Cinzia Nagihara, Seiichi Grygorczuk, Jurek International Space Science Institute Bern Switzerland DLR Institute of Planetary Research Berlin Germany Jet Propulsion Laboratory California Institute of Technology Pasadena United States DLR Institute of Space Systems Bremen Germany Astronika Warsaw Poland Department of Civil Engineering University of Kaiserslautern Kaiserslautern Germany Johns Hopkins Applied Physics Laboratory LaurelMD20723 United States DLR Institute of System Dynamics and Control Oberpfaffenhofen Germany DLR Microgravity User Support Center Cologne Germany Department of Geosciences Texas Tech University Lubbock United States

The NASA InSight lander mission to Mars payload includes the Heat Flow and Physical Properties Package HP3 to measure the surface heat flow. The package was designed use a small penetrator - nicknamed the mole - to implement a vertical string of temperature sensors in the soil to a depth of 5 m. The mole itself is equipped with sensors to measure a thermal conductivity- depth profile as it proceeds to depth. The heat flow would be calculated from the product of the temperature gradient and the thermal conductivity. To avoid the perturbation caused by annual surface temperature variations, the measurements would be taken at a depth between 3 m and 5 m. The mole had been designed to penetrate cohesionless soil similar in rheology to Quartz sand which was expected to provide a good analogue material for Martian sand. The sand would provide friction to the buried mole hull to balance the remaining recoil of the mole hammer mechanism that drives the mole forward. Unfortunately, the mole did not penetrate more than roughly a mole length of 40 cm. The failure to penetrate deeper was largely due to a cohesive duricrust of a few tens of centimeter thickness that failed to provide the required friction. Although a suppressor mass and spring as part of the mole hammer mechanism absorbed much of the recoil, the available mass did not allow designing a system that would have eliminated the recoil. The mole penetrated to 40 cm depth benefiting from friction provided by springs in the support structure from which it was deployed. It was found in addition that the Martian soil provided unexpected levels of penetration resistance that would have motivated to designing a more powerful mole. The low weight of the moIe support structure was not enough to guide the mole penetrating vertically. It is concluded that more mass would have allowed to design a more robust system with little or no recoil, more energy of the mole hammer mechanism and a more massive support structure. In additio

关键词： Friction

Claimed detection of PH3 in the clouds of Venus is consistent with mesospheric SO2

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arXiv 2021年

作者： Lincowski, Andrew P. Meadows, Victoria S. Crisp, David Akins, Alex B. Schwieterman, Edward W. Arney, Giada N. Wong, Michael L. Steffes, Paul G. Parenteau, M. Niki Domagal-Goldman, Shawn Department of Astronomy and Astrobiology Program University of Washington Box 351580 SeattleWA98195 United States NASA Nexus for Exoplanet System Science Virtual Planetary Laboratory Team University of Washington Box 351580 SeattleWA98195 United States Jet Propulsion Laboratory California Institute of Technology Earth and Space Sciences Division PasadenaCA91011 United States Jet Propulsion Laboratory California Institute of Technology Instruments Division PasadenaCA91011 United States Department of Earth and Planetary Sciences University of California RiversideCA92521 United States Blue Marble Space Institute of Science SeattleWA United States NASA/Goddard Space Flight Center GreenbeltMD20771 United States School of Electrical and Computer Engineering Georgia Institute of Technology AtlantaGA30332-0250 United States MS 239-4 Space Science Division NASA Ames Research Center Moffett FieldCA United States

The observation of a 266.94 GHz feature in the Venus spectrum has been attributed to PH3 in the Venus clouds, suggesting unexpected geological, chemical or even biological processes. Since both PH3 and SO2 are spectrally active near 266.94 GHz, the contribution to this line from SO2 must be determined before it can be attributed, in whole or part, to PH3. An undetected SO2 reference line, interpreted as an unexpectedly low SO2 abundance, suggested that the 266.94 GHz feature could be attributed primarily to PH3. However, the low SO2 and the inference that PH3 was in the cloud deck posed an apparent contradiction. Here we use a radiative transfer model to analyze the PH3 discovery, and explore the detectability of different vertical distributions of PH3 and SO2. We find that the 266.94 GHz line does not originate in the clouds, but above 80 km in the Venus mesosphere. This level of line formation is inconsistent with chemical modeling that assumes generation of PH3 in the Venus clouds. Given the extremely short chemical lifetime of PH3 in the Venus mesosphere, an implausibly high source flux would be needed to maintain the observed value of 20±10 ppb. We find that typical Venus SO2 vertical distributions and abundances fit the JCMT 266.94 GHz feature, and the resulting SO2 reference line at 267.54 GHz would have remained undetectable in the ALMA data due to line dilution. We conclude that nominal mesospheric SO2 is a more plausible explanation for the JCMT and ALMA data than PH3 © 2021, CC BY.

关键词： Radiative transfer

The behavior, constraint, and scenario (BeCoS) tool: A web-based software application for modeling behaviors and scenarios

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The behavior, constraint, and scenario (BeCoS) tool: A web-b...

AIAA Aerospace Sciences Meeting, 2018

作者： Kaderka, Justin D. Rozek, Matthew L. Arballo, John K. Wagner, David A. Ingham, Michel D. System Architectures and Behaviors Group Jet Propulsion Laboratory California Institute of Technology M/S 321-425P PasadenaCA91109 United States Flight System Systems Engineering Group Jet Propulsion Laboratory California Institute of Technology M/S 321-525E PasadenaCA91109 United States Structure of the Universe Group Jet Propulsion Laboratory California Institute of Technology M/S 169-327 PasadenaCA91109 United States System Architectures and Behaviors Group Jet Propulsion Laboratory California Institute of Technology M/S 301-445P PasadenaCA91109 United States Software and Information Systems Engineering Group Jet Propulsion Laboratory California Institute of Technology M/S 321-541 PasadenaCA91109 United States

ISBN: (数字)9781624105241

ISBN: (纸本)9781624105241

The Behavior, Constraint, and Scenario (BeCoS) tool has been developed to allow engineers to specify system and component behaviors. The tool is a web application that is developed in JavaScript and uses the React framework for the user interface and Redux for maintaining application state. The foundation of the tool is its underlying ontology, which expands upon a previously-defined behavior ontology with a scenario ontology. The behavior ontology includes elements like behaving elements, state variables, parameters, and constraints, while the scenario ontology includes core constructs like activities, temporal constraints, and timepoints. BeCoS allows users to easily create behaving elements and to specify their state variables, parameters, state machines, and constraints. BeCoS also allows users to develop temporal constraint networks that specify constraints on component states over time. BeCoS is a prototype tool that has been deployed and tested by systems engineers on the Europa Clipper project, which generated several use cases and helped steer its current developmental effort. By enabling systems engineers to specify behavior in a semantically-rigorous manner, BeCoS is an enabling technology for analyses that previously could not be performed, and when exporting its model to other tools, allows for consistent behavior models to be used. © 2018 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Ontology

Mars 2020 surface mission performance analysis: Part 2. surface traversability

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Mars 2020 surface mission performance analysis: Part 2. surf...

AIAA Space and Astronautics Forum and Exposition, 2018

作者： Ono, Masahiro Heverly, Matthew Rothrock, Brandon Ishimatsu, Takuto Almeida, Eduardo Calef, Fred Soliman, Tariq Williams, Nathan Gengl, Hallie Nicholas, Austin Stilley, Erisa K. Otsu, Kyohei Trautman, Marshall Lange, Robert Milkovich, Sarah Jet Propulsion Laboratory California Institute of Technology PasadenaCA91106 United States Research Technologist Mobility and Robotics Systems Section Jet Propulsion Laboratory California Institute of Technology PasadenaCA91106 United States Mechanical Engineering Section Jet Propulsion Laboratory California Institute of Technology PasadenaCA91106 United States Science Data Understanding Group Jet Propulsion Laboratory California Institute of Technology PasadenaCA91106 United States Geophysics and Planetary Geosciences Section Jet Propulsion Laboratory California Institute of Technology PasadenaCA91106 United States Data Visualization Developer Instrument Software and Science Data Systems PasadenaCA91106 United States Software Systems Engineering Section Jet Propulsion Laboratory California Institute of Technology PasadenaCA91106 United States Mission Systems Engineering Section Jet Propulsion Laboratory California Institute of Technology PasadenaCA91106 United States Science Systems Engineer Jet Propulsion Laboratory California Institute of Technology 394B PasadenaCA91106 United States

ISBN: (纸本)9781624105753

– The Mars 2020 Rover Mission (M2020) is characterized by demanding requirement on the distance and time for traveling between scientific Regions Of Interest (ROIs). As a result, surface traversability is one of the major driving factors for the landing site selection of M2020. With the newly developed Mars Terrain Traversability analysis Tools (MTTT), we performed traversability analysis of the eight candidate landing sites with an unprecedented granularity. This paper describes the MTTT analysis capabilityies, as well as how the MTTT capabilities were used to downselect from eight to three candidate landing sites for further evaluation. © 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Site selection

Lunar flashlight cubeSat GNC system development for lunar exploration 69

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Lunar flashlight cubeSat GNC system development for lunar ex...

69th International Astronautical Congress: #InvolvingEveryone, IAC 2018

作者： Lai, Peter C. Sternberg, David C. Haw, Robert J. Gustafson, Eric D. Adell, Phillipe C. Baker, John D. Flight System Engineering Section NASA Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Dr PasadenaCA91109 United States

JPL is developing the Lunar Flashlight (LF) CubeSat mission, a 6U 14 kg spacecraft whose objective is to measure potential surface water ice deposits in the permanently shadowed region (PSR) of the moon in preparation of future possible human lunar exploration. This mission will become the first interplanetary CubeSat to orbit the Moon. It uses a green propulsion system as well as an instrument with IR laser technology to search for volatiles in a specific region of the moon. The Guidance, Navigation and Control (GNC) system is crucial for delivering the spacecraft from Earth to Lunar orbit and to execute scientific measurement. Due to the challenging lunar orbit insertion and high spin rate out of launch vehicle's dispenser, the initial design concept using solar sail propulsion accompanied with small commercial-on-the-shelf (COTS) reaction wheels was abandoned mid-course and replaced by a green propulsion system along with larger reaction wheels, both newly developed for LF. However, using thrusters for small CubeSat created additional difficulties in controlling the spacecraft attitude. The story of the GNC system development, qualifications, technical challenges encountered, and lessons learned are discussed in this paper. Copyright © 2018 by the International Astronautical Federation.

关键词： Surface waters

Carbonates identified by the Curiosity rover indicate a carbon cycle operated on ancient Mars

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Science (New York, N.Y.) 2025年第6744期388卷 292-297页

作者： Benjamin M Tutolo Elisabeth M Hausrath Edwin S Kite Elizabeth B Rampe Thomas F Bristow Robert T Downs Allan Treiman Tanya S Peretyazhko Michael T Thorpe John P Grotzinger Amelie L Roberts P Douglas Archer David J Des Marais David F Blake David T Vaniman Shaunna M Morrison Steve Chipera Robert M Hazen Richard V Morris Valerie M Tu Sarah L Simpson Aditi Pandey Albert Yen Stephen R Larter Patricia Craig Nicholas Castle Douglas W Ming Johannes M Meusburger Abigail A Fraeman David G Burtt Heather B Franz Brad Sutter Joanna V Clark William Rapin John C Bridges Matteo Loche Patrick Gasda Jens Frydenvang Ashwin R Vasavada Department of Earth Energy and Environment University of Calgary Calgary AB Canada. Department of Geoscience University of Nevada-Las Vegas Las Vegas NV USA. Department of Geophysical Sciences University of Chicago Chicago IL USA. Astromaterials Research and Exploration Science Division NASA Johnson Space Center Houston TX USA. Exobiology Branch NASA Ames Research Center Moffett Field CA USA. Department of Geosciences University of Arizona Tucson AZ USA. Lunar and Planetary Institute Universities Space Research Association Houston TX USA. Amentum NASA Johnson Space Center Houston TX USA. Department of Astronomy University of Maryland College Park MD USA. Solar System Exploration Division NASA Godard Space Flight Center Greenbelt MD USA. Center for Research and Exploration in Space Science and Technology NASA Goddard Space Flight Center Greenbelt MD USA. Division of Geological and Planetary Sciences California Institute of Technology Pasadena CA USA Pasadena CA USA. Department of Earth Science and Engineering Imperial College London London UK. Planetary Science Institute Tucson AZ USA. Earth and Planets Laboratory Carnegie Institution for Science Washington DC USA. Department of Earth and Planetary Sciences Rutgers University New Brunswick Piscataway NJ USA. Texas State University-Amentum Johnson Space Center Engineering Technology and Science II NASA Johnson Space Center Houston TX USA. Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA. Institut de Recherche en Astrophysique et Planétologie Université de Toulouse CNRS Centre National d'Études Spatiales Toulouse France. Space Park Leicester University of Leicester Leicester UK. Los Alamos National Laboratory Los Alamos NM USA. Globe Institute University of Copenhagen Copenhagen K Denmark.

Ancient Mars had surface liquid water and a dense carbon dioxide (CO)-rich atmosphere. Such an atmosphere would interact with crustal rocks, potentially leaving a mineralogical record of its presence. We analyzed the composition of an 89-meter stratigraphic section of Gale crater, Mars, using data collected by the Curiosity rover. An iron carbonate mineral, siderite, occurs in abundances of 4.8 to 10.5 weight %, colocated with highly water-soluble salts. We infer that the siderite formed in water-limited conditions, driven by water-rock reactions and evaporation. Comparison with orbital data indicates that similar strata (deposited globally) sequestered the equivalent of 2.6 to 36 millibar of atmospheric CO. The presence of iron oxyhydroxides in these deposits indicates that a partially closed carbon cycle on ancient Mars returned some previously sequestered CO to the atmosphere.

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ALMA Observations of the DART Impact: Characterizing the Ejecta at Sub-Millimeter Wavelengths

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arXiv 2023年

作者： Roth, Nathan X. Milam, Stefanie N. Remijan, Anthony J. Cordiner, Martin A. Busch, Michael W. Thomas, Cristina A. Rivkin, Andrew S. Moullet, Arielle Roush, Ted L. Siebert, Mark A. Li, Jian-Yang Fahnestock, Eugene G. Trigo-Rodríguez, Josep M. Opitom, Cyrielle Hirabayashi, Masatoshi Solar System Exploration Division Astrochemistry Laboratory Code 691 NASA Goddard Space Flight Center 8800 Greenbelt Rd. GreenbeltMD20771 United States Department of Physics The Catholic University of America 620 Michigan Ave. N.E. WashingtonDC20064 United States National Radio Astronomy Observatory 520 Edgemont Rd CharlottesvilleVA22903 United States SETI Institute 189 Bernardo Avenue Suite 200 Mountain ViewCA94043 United States Northern Arizona University Department of Astronomy and Planetary Science P.O. Box 6010 FlagstaffAZ86011 United States Johns Hopkins University Applied Physics Laboratory 11100 Johns Hopkins Rd. LaurelMD20723 United States Planetary Systems Branch MS 245-3 Moffett FieldCA94035 United States Department of Astronomy University of Virginia CharlottesvilleVA22904 United States Planetary Science Institute 1700 East Fort Lowell Suite 106 TucsonAZ85719 United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA91109 United States Campus UAB Carrer de Can Magrans s/n Barcelona Catalonia Cerdanyola del Vallés08193 Spain Institute for Astronomy University of Edinburgh Royal Observatory EdinburghEH9 3HJ United Kingdom Department of Aerospace Engineering Department of Geosciences Auburn University AuburnAL United States Daniel Guggenheim School of Aerospace Engineering Georgia Institute of Technology AtlantaGA United States

We report observations of the Didymos-Dimorphos binary asteroid system using the Atacama Large Millimeter/Submillimeter Array (ALMA) and the Atacama Compact Array (ACA) in support of the Double Asteroid Redirection Test (DART) mission. Our observations on UT 2022 September 15 provided a pre-impact baseline and the first measure of Didymos-Dimorphos’ spectral emissivity at λ = 0.87 mm, which was consistent with the handful of siliceous and carbonaceous asteroids measured at millimeter wavelengths. Our post-impact observations were conducted using four consecutive executions each of ALMA and the ACA spanning from T+3.52 to T+8.60 hours post-impact, sampling thermal emission from the asteroids and the impact ejecta. We scaled our pre-impact baseline measurement and subtracted it from the post-impact observations to isolate the flux density of mm-sized grains in the ejecta. Ejecta dust masses were calculated for a range of materials that may be representative of Dimorphos’ S-type asteroid material. The average ejecta mass over our observations is consistent with 1.3–6.4×107 kg, with the lower and higher values calculated for amorphous silicates and for crystalline silicates, respectively. Owing to the likely crystalline nature of S-type asteroid material, the higher value is favored. These ejecta masses represent 0.3–1.5% of Dimorphos’ total mass and are in agreement with lower limits on the ejecta mass based on measurements at optical wavelengths. Our results provide the most sensitive measure of mm-sized material in the ejecta and demonstrate the power of ALMA for providing supporting observations to spaceflight missions. © 2023, CC BY.

关键词： Radio astronomy

Incorporating AEGIS autonomous science into mars science laboratory rover mission operations 15th

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Incorporating AEGIS autonomous science into mars science lab...

15th International Conference on Space Operations, SpaceOps 2018

作者： Francis, Raymond Estlin, Tara Doran, Gary Gaines, Daniel Johnstone, Stephen Montaño, Suzanne Peret, Laurent Mousset, Valérie Gasnault, Olivier Frydenvang, Jens Wiens, Roger C. Schaffer, Steven Pavri, Betina Verma, Vandana Chattopadhyay, Debarati Bornstein, Benjamin Mittal, Nimisha Deflores, Lauren Jet Propulsion Laboratory Machine Learning and Instrument Autonomy Research Group California Institute of Technology PasadenaCA91109 United States Jet Propulsion Laboratory Artificial Intelligence Research Group California Institute of Technology PasadenaCA91109 United States Intelligence and Space Research Division Los Alamos National Laboratory Los AlamosNM87545 United States Telespazio France FIMOC Toulouse France FIMOC Centre National d’Études Spatiales Toulouse France FIMOC Institut de Recherche en Astrophysique et Planétologie Université de Toulouse CNRS CNES UPS France Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark Los Alamos National Laboratory Intelligence and Space Research Division Los AlamosNM87545 United States Jet Propulsion Laboratory Artificial Intelligence Research Group California Institute of Technology PasadenaCA91109 United States Jet Propulsion Laboratory Instrument Operations Engineering Group California Institute of Technology PasadenaCA91109 United States Jet Propulsion Laboratory Robot Operations Group California Institute of Technology PasadenaCA91109 United States Jet Propulsion Laboratory Planning and Sequencing Systems Group California Institute of Technology PasadenaCA91109 United States Jet Propulsion Laboratory Electronics and Software Section California Institute of Technology PasadenaCA91109 United States Jet Propulsion Laboratory Science Planning Group California Institute of Technology PasadenaCA91109 United States Jet Propulsion Laboratory Instrument System Engineering Group California Institute of Technology PasadenaCA91109 United States

ISBN: (数字)9781624105623

ISBN: (纸本)9781624105623

The AEGIS (Autonomous Exploration for Gathering Increased Science) intelligent targeting software system has been in use on the Mars Science laboratory (MSL) mission since 2016. The system allows on-board autonomous selection of targets for the ChemCam remote geochemistry instrument based on analysis of images taken by the rover. This paper describes the deployment of AEGIS to MSL and the operational use of the system since rollout to science operations in May of 2016. We describe how MSL Science Operations have adapted to include autonomous target selection, both in procedures and in exploration strategies, and how mission planners and scientists have used AEGIS autonomy to enhance their work on the MSL mission. © 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Rovers